Principles and procedures of dispensing prescriptions

Syllabus:

Principles involved and procedures adopted in dispensing of

Liquid preparations such as mixtures, suspensions, emulsions, solutions, lotions, and liniments;

Semisolid preparations such as ointments, creams, pastes, jellies and suppositories;

Solid dosage forms such as powders, capsules, effervescent powders, tablet triturates and lozenges;

paints, sprays, inhalations and poultices.

Reference Books:

1. Dispensing Pharmacy, R.M.Mehta

2. Cooper & Guns Dispensing

3. Pharmaceutics-II, A.K. Gupta

4. Remington’s Pharmaceutical Sciences.

MIXTURES

Definition: A mixture is a liquid preparation intended for oral administration in which drugs may be dissolved, suspended or dispersed in a suitable vehicle. Generally several doses are contained in a bottle.

Classification: Mixtures may be classified as follows:

1. Simple mixtures

2. Mixtures containing diffusible solids

3. Mixtures containing indiffusible solids

4. Mixture containing precipitate forming liquids

1. Simple mixture

A simple mixture is one that contains only soluble ingredients.

Method of dispensing

(a) The solid substances are dissolved in 3/4^th volume of the vehicle.

(b) The solution is examined against light for any foreign particle. If foreign particles are present then the solution is passed through cotton wool. Little vehicle is poured through the cotton wool to wash down any drug present in the wool.

(d) More vehicle is added to produce the final volume.

(e) The mixture is transferred to a bottle, capped tightly, polished and labeled.

Container: Narrow mouthed, screw capped, colorless, plain bottle.

Label: The ink used in the label Black.

Special instructions: None

Formula		Use
Ferric ammonium citrate 200gm Chloroform water q.s. 1000ml	Active ingredient Vehicle	Iron haematinic
Ferrous sulphate 3.0g Ascorbic acid 0.1g Orange syrup 10.0ml Chloroform water q.s. 100ml	Active ingredient Antioxidant Flavor Vehicle	Iron haematinic
Ammonium chloride 0.3g Ammonium bicarbonate 0.2g Liquid extract of liquorice 0.5ml Chloroform water q.s. 15.0ml	Active ingredient Active ingredient Active ingredient Vehicle	Expectorant

2. Mixture containing diffusible solids

Diffusible solids are those, which are not soluble in water, but on shaking they can be mixed with it and remain evenly distributed throughout the liquid for a sufficiently long time. So dose transfer is uniform.

However, on standing the insoluble solids settle at the bottom. Whenever a dose is taken the bottle should be shaken to redisperse the solid.

Examples of diffusible solids: Bismuth carbonate, light kaolin, magnesium oxide, magnesium carbonate, magnesium trisilicate etc.

Method of dispensing

(a) All the solid ingredients are powdered in a mortar and mixed thoroughly.

(b) Small amount of vehicle is added to the powder and triturated to form a smooth paste.

(d) If foreign particles are present then the mixture is strained though a muslin cloth.

(e) Liquid ingredient, if any, is added and the volume is produced with the vehicle.

(f) The mixture is transferred to the bottle.

Container: Narrow mouthed, screw capped, colorless, plain bottle.

Label: The ink used in the label Black.

Special instruction(s): SHAKE WELL BEFORE USE

Formula			Use
Magnesium sulfate Light magnesium carbonate Peppermint water	30g 4g 180ml	Active ingredient Active ingredient Vehicle	Saline purgative
Light kaolin Light magnesium carbonate Sodium bicarbonate Peppermint water	2.0g 0.5g 0.5g 15.0ml	Active ingredient Active ingredient Active ingredient Vehicle	Antacid and carminative

3. Mixture containing indiffusible solids

Indiffusible solids are those substances, which are not soluble in water and they do not uniformly distribute throughout the vehicle. Even after shaking they settle quickly, therefore it becomes difficult to measure the dose accurately. In this type of mixture a suspending agent is used that increases the viscosity of the vehicle and thus reduces the rate of settling of the particles.

Examples of indiffusible solids: Chalk powder, acetyl salicylic acid etc.

Examples of suspending agents: Compound tragacanth powder, Tragacanth mucilage, tragacanth powder.

Formula of Compound tragacanth powder (Acacia 20%, tragacanth 15%, starch 20% and sucrose 45%.)

In 100ml of final mixture

Compound tragacanth powder to be taken 2-4g,

Tragacanth mucilage 25ml and

Tragacanth powder 0.2g.

Method of dispensing

(a) Indiffusible, diffusible powders and calculated amount of suspending agent are triturated in a mortar.

(b) Small mount of vehicle is added to the powder and triturated to make a smooth paste.

(d) Liquid ingredient, if any, is added. Volume is made up with the rest of the vehicle.

(e) The mixture is transferred to the bottle, capped, polished and labeled.

Container: Narrow mouthed, screw capped, colorless, plain bottle.

Label: The ink used in the label Black.

Special instruction(s): SHAKE WELL BEFORE USE

Formula			Use
Bismuth carbonate Chalk powder Kaolin Tincture catechu Water q.s.	1g 1g 4g 2ml 30ml	Diffusible Indiffusible Diffusible Astringent Vehicle	Antidiarrhoeal

4. Mixture containing precipitate forming liquid

Some liquid preparations contain resinous matter that is precipitated on addition of water. This precipitates sticks to the container and forms clots.

To disperse this type of liquid first a protective colloid is dispersed in vehicle and then the precipitate forming liquid is added with constant stirring. The resinous particles are coated with the protective colloid.

Examples of precipitate forming liquids:

Compound benzoin tincture

Benzoin Tincture

Lobelia ethereal tincture

Myrrh tincture

Tolu Tincture

Examples of suspending agents: Compound tragacanth powder, Tragacanth mucilage

Method of dispensing by using Compound tragacanth powder

(a) Any insoluble solid is powdered in a mortar and mixed with compound tragacanth powder. Small amount of the vehicle is added to form a smooth paste. The volume is produced to 50% of the final volume with the vehicle.

(b) The precipitate forming liquid is taken in a dry measuring cylinder and is added to the suspension slowly, while the suspension is stirred rapidly. The gum particles coat the resinous particles and give a hydrophilic property to the resin particles.

(c) If any electrolytes are there it should be added only after the resin particles are completely coated with gum, otherwise heavy clotting will take place.

(d) Strained it necessary and volume is made up with vehicle.

(e) The mixture is transferred to the bottle, capped, polished and labeled.

Method of dispensing by using Tragacanth mucilage

(a) Mucilage is taken and added with equal volume of vehicle in a beaker.

(b) The precipitate forming liquid is measured in a dry measuring cylinder and added into the center of the mucilage with constant stirring.

(d) The mixture is strained, if required, and the volume is produced with vehicle.

(e) The mixture is transferred to the bottle, capped, polished and labeled.

Container: Narrow mouthed, screw capped, colorless, plain bottle.

Label: The ink used in the label Black.

Special instruction(s): SHAKE WELL BEFORE USE

Formula
Lobelia Ethereal Tincture Tragacanth Mucilage Potassium iodide Stramonium tincture Chloroform water	Precipitate forming liquid, active ingredient Protective colloid Electrolyte, active ingredient Active ingredient Vehicle

SUSPENSIONS

Suspensions are biphasic systems where solid is dispersed in liquid. These systems are unstable. The particles settle down with time. Rate of settling may be slowed down by adding a suitable suspending agent. These agents increases the viscosity of the vehicle hence they are also called as thickening agent.

Properties of a good suspension

1. After shaking, the medicament stays in suspension long enough for removal of the correct dose from oral products and the correct proportion to active ingredients from external preparations.

2. The sediment produced on standing is easily redispersed. Deflocculated system produces cake, which is not redispersible. So the system must be partially flocculated with the help of flocculating agents.

3. It is easily pourable.

4. It is comparatively free from large particles, which gives a bad appearance, gives a gritty taste to oral preparation and produces irritation on the skin if it is an external product.

Classification of thickening agents:

1. Polysaccharides

(a) Natural e.g. Gum acacia, Gum tragacanth, Starch, sodium alginate

(b) Semi-synthetic e.g. Methylcellulose, Hydroxyethylcellulose, Sodium carboxymethylcellulose,

Microcrystalline cellulose

2. Inorganic clays e.g. Bentonite, Veegum (Aluminium magnesium silicate), Hectorite

3. Synthetic e.g. Carbomer (Carbopol), Colloidal Silicon Dioxide.

Preparation of suspensions

1. Suspensions containing diffusible solids – same as Mixture containing diffusible solids

2. Suspensions containing indiffusible solids – same as Mixture containing indiffusible solids

3. Suspensions containing poorly wettable solids

4. Suspensions containing precipitate forming liquid – same as Mixture containing precipitate forming liquid.

5. Suspensions produced by chemical reactions

Preparation of suspension containing poorly wettable solids

Principle:

Some substances, e.g. sulphur and hydrocortisone (a steroid) are booth insoluble in water and are poorly wetted by it. When these powders are added to water they forms clump and become difficult to disperse. On shaking, it produces foam that is stabilized by a layer of non-wettable particles on the water-air interface.

To solve these problems a suitable wetting agent is added.

For external preparations: Quillaia extract (it contains saponin that acts as wetting agent), Sodium lauryl sulfate (SLS)

For internal preparations (i.e. oral preparations): Polysorbates (Tween 80), alcohol, glycerol etc.

General method of preparation

(a) The poorly wettable solids are taken in a mortar and triturated with the wetting agents.

(b) Gradually vehicle is added to it.

Container: For oral preparation: Narrow mouthed, screw capped, colorless, plain bottle.

For external preparation: Narrow mouthed, screw capped, colorless, fluted bottle.

Label: The ink used in the label Black.

Special instruction(s): SHAKE WELL BEFORE USE

For external preparation(s) FOR EXTERNAL USE ONLY

Formula
Precipitated sulfur Alcohol 95%v/v Glycerol Quillaia Tincture Calcium hydroxide solution	Poorly wettable solid Wetting agent Wetting agent Wetting agent Vehicle

5. Suspensions produced by chemical reactions

Some times two reagents are added to react in the solution to form a very fine suspension. The particles thus produced are very fine and diffusible, so no suspending agent is required.

Example: Zinc sulphide lotion B.P.C. that is used to treat acne and scabies.

Formula
Sulphurated potash Zinc sulfate Camphor water	Reagent 1 Reagent 2 Vehicle

Method of preparation:

(a) Sulphurated potash is dissolved in ½ of the vehicle.

(b) Zinc sulfate is dissolved in another ½ of the vehicle.

(d) The suspension is transferred to a tared bottle and the volume is made up with the vehicle.

Container: For external preparation: Narrow mouthed, screw capped, colorless, fluted bottle.

Label: The ink used in the label Black.

Special instruction(s): SHAKE WELL BEFORE USE, KEEP IN A DARK CUPBOARD

For external preparation(s) FOR EXTERNAL USE ONLY

EMULSIONS

An emulsion is a biphasic liquid preparation containing two immiscible liquid phases, one of which is dispersed as fine globules (or droplets) in another. The fine globules are called dispersed phase and the other is called continuous phase.

Emulsions are unstable so the system is stabilized by addition of a third agent. It is called emulsifier or emulsifying agent or emulgent.

Types of emulsions:

The emulsions are of two types:

			Dispersed phase	Continuous phase
1	Oil in water type	o/w	Oil	Water
2	Water in oil type	w/o	Water	Oil

Tests of identification of type of emulsion

The following tests are done to distinguish between o/w and w/o type emulsions.

Test	Method	Observation	Inference
Miscibility test	Emulsion is taken in a beaker and small volume of water is added to it.	The water mixes with the emulsion The water remains separate.	o/w type w/o type
Dye test	Scarlet red (oil soluble) is mixed with the emulsion and a drop of it is placed on a microscopic slide and viewed under microscope.	Droplets are red, background is colorless Droplets are colorless, background is red.	o/w type w/o type
Conductivity test	A pair of electrodes are dipped in an emulsion and the electrodes are connected to a battery, a bulb and a switch. The switch is put on.	The bulb glows. The bulb did not glow.	Water conducts electricity, so o/w w/o

Classification of emulsifiers:

EMULSIFIERS

Hydrophilic colloids

Finely divided solid particles

Synthetic Surface Active Agents

Vegetable source

Gum acacia

Tragacanth

Starch

Animal source

Wool fat

Egg yolk

Gelatin

Synthetic

Methyl cellulose

Hydroxyethyl cellulose,

Colloidal clays:

Bentonite (aluminium silicate)

Veegum (magnesium aluminium silicate).

Anionic

Potassium stearate

Sodium lauryl sulphate

Cationic

Cetyl trimethyl ammonium bromide (or cetrimide)

Ampholytic

N-dodecyl alanine

Non-ionic

Sorbitan mono-oleate

(TWEEN)

Polyoxyethylene sorbitan mono-oleate (Polysorbate)

Other ingredients used in emulsion: Preservatives, Antioxidants, Falvors.

Method of preparation of emulsions

The following methods are commonly used for the preparation of emulsions on a small scale:

1. Dry gum method 2. Wet gum method 3. Bottle method 4. Others

For preparing any emulsion with gum acacia first a primary emulsion is produced (w/o type). Then it is diluted with more volume of water to prepare the final emulsion (o/w type). The formula is as follows:

Type of oil	Example of oil	Ratio of oil:water:gum	Method used
Fixed oil	Castor oil, Almondoil, Arachis oil, Cod-liver oil	4 : 2 : 1	Wet gum, Dry gum
Mineral oil	Liquid paraffin	3 : 2 : 1	Wet gum, Dry gum
Volatile oil	Turpentine oil, Peppermint oil, Cinnamon oil	2 : 2 : 1	Bottle method

1. Dry gum method

1. The required quantity of oil is measured in a dry container and taken in a mortar.

2. The calculated quantity of the gum acacia (i.e. 1part) is taken in the mortar and triturated to form a uniform paste.

3. The calculated quantity of water to form primary emulsion (i.e. 2parts) is taken triturated vigorously till a clicking sound is produced and the product becomes whitish. The emulsion produced at this stage is called primary emulsion (w/o).

4. Rest of the water (or vehicle) is added in small volume and mixed thoroughly to produce the final emulsion.

5. The emulsion is transferred to the bottle, capped, polished and labeled.

2. Wet gum method

1. The calculated quantity of the gum acacia (i.e. 1part) is taken in a mortar.

2. The calculated quantity of water is taken in the mortar and triturated to form mucilage.

3. The oil is added in small portions to the mucilage and triturated vigorously until a clicking sound is produced and the product becomes whitish. The emulsion produced at this stage is called primary emulsion (w/o).

4. Rest of the water (or vehicle) is added in small volume and mixed thoroughly to produce the final emulsion.

5. The emulsion is transferred to the bottle, capped, polished and labeled.

3. Bottle method

Bottle method is used for preparation containing volatile oils and low viscosity oils.

The proportion of oil : water : gum = 2 : 2 : 1

1. The required quantity of oil (2 parts) is measured and is transferred into a large bottle.

2. Calculated quantity of powdered acacia (1 part) is taken in the bottle and closed. The bottle is shaken vigorously until the oil and gum are mixed thoroughly.

3. The calculated amount of water (2 parts) is taken in the bottle and closed. It is shaken vigorously to form the primary emulsion.

4. Rest of the water is added in small portions and shaken vigorously to mix.

5. The emulsion is transferred to the final bottle, closed, polished and labeled.

4. Other methods

A coarse emulsion is produced which is then passed through hand homogenizer many times until a uniform emulsion is produced.

Examples of homogenizers are: Hand homogenizer, Silverson mixer homogenizer, Colloid mill.

These homogenizers are based on the principle that the larger globules in coarse emulsions are broken down into smaller globules when passed through small orifice (hole) of the instruments.

Storage: The emulsions should be packed in a bottle leaving space over the preparation for shaking before use.

Should be stored in a cool place. It should not be stored in high temperature or in refrigerator (it will crack).

Emulsions for internal use: Packed in narrow mouthed plain bottle.

Emulsions for external use: Packed in wide (mouthed if viscous), fluted bottle.

Label: SHAKE WELL BEFORE USE.

Examples:

Castor oil 8ml Water q.s. 30ml Purgative	Arachis oil 50ml Water q.s. 200ml Purgative	Cod liver oil 30ml Syrup 12ml Ferric ammonium citrate 4g Cinnamon water q.s. 90ml Vitamin A&D with iron supplement
Liquid paraffin 8ml Water q.s. 30ml Purgative

SOLUTIONS

A solution is a clear homogenous mixture that is prepared by dissolving a solid, liquid or gas in a liquid.

Classification

MIXTURES: Already discussed previously under simple mixture (page 1).

SYRUP:

A syrup is a concentrated , nearly saturated solution of sucrose in purified water. The concentration of sugar is 66.7%w/w (or 85%w/v). The syrups are sweet viscous preparations.

Classification: 1. Medicated syrup: Contains medicinal substances.

2. Flavored syrup: Contains flavoring agents, used for flavoring a liquid oral preparation.

Formulation of syrups

1. Vehicle: Purified water

2. Adjuncts: Chemical stabilizers: Glycerin, sorbitol or propylene glycol is added in small quantity to prevent crystallization. Tween80 may be added to dissolve certain insoluble substances and thus produce a clear solution.

Coloring agents: Amaranth (pink red), Compound Tartrazine (yellow), Green S with Tartrazine (Green).

Flavoring agents: Tinctures: Lemon tincture, ginger tincture.

Fruit juices Raspberry, Wild cherry

Essence Vanilla, Orange.

Preservative: Syrup containing 67.7%w/w sucrose has self-preservative action due to high osmotic pressure. It prevents the growth of bacteria, fungi and moulds. So no preservative in needed. In dilute solutions benzoic acid, sodium benzoate, methyl paraben may be used.

Storage of syrup:

Stored in narrow mouthed, well closed, amber color or plain bottle.

Instruction: KEEP IT IN A COOL PLACE.

ELIXIRS

See CHAPTER2: Pharmacopoeial preparations, page-3.

Storage Stored in narrow mouthed, well closed, amber color or plain bottle.

Instruction: KEEP IT IN A COOL PLACE.

LINCTUS

See CHAPTER2: Pharmacopoeial preparations, page-4.

LINIMENT

· Liniments are fluid, semi-fluid or semi-solid preparations intended for application to the skin.

· They may be alcoholic or oily solutions or emulsions. Alcohol helps in penetration of drug into the skin. In oily liniment arachis oil is generally used, it helps in spreading the liniment on the skin.

· Most of them are massaged into the skin (counter irritant or stimulating type).

· Generally liniments contain medicaments possessing analgesic (reduces pain), rubefacient (produce local reddening of skin when rubbed) and counter irritant (counters strong irritation).

· The liniments should not be applied on broken skin, because it will produce excessive irritation.

Storage: Stored in fluted bottle (to indicate an external preparation), well-closed air tight container. It must be stored in a cool place, because it contains volatile ingredients.

Instruction: FOR EXTERNAL USE ONLY

“Shake the bottle before use.”

“Not to be applied to open wound or broken skin”.

Example: Turpentine liniment

Rx Soft soap 8g

Camphor 5g

Turpentine oil 65ml

Purified water, q.s. 100ml

Procedure:

(i) In a dry beaker, camphor is dissolved in turpentine oil.

(ii) Soft soap is dissolved in a mortar with small amount of purified water. The oil solution is added in small amount to the soap solution and mixed thoroughly until a smooth creamy emulsion is formed.

(iii) Sufficient purified water is added to the creamy emulsion and mixed thoroughly.

(iv) The preparation is transferred to a bottle, polished and labeled.

LOTIONS

Lotions are liquid preparations for external application without friction.

The lotion is soaked in a absorbent cotton or gauze and are applied on the skin

Lotions may be used for local cooling, soothing, protective or antiseptic purposes.

Container: Dispensed in a colored, fluted bottle.

Instruction: FOR EXTERNAL USE ONLY

“Shake well before use” – because on long standing some ingredient may separate out.

Examples: Calamine lotion (for preparation see Practical note), Salicylic acid lotion BP

OINTMENT

Ointments are semi-solid preparations meant for external application to the skin or mucous membrane. The drug may be dissolved, suspended or emulsified in an ointment base. They may contain a preservative.

Classification of ointment bases

1. Oleaginous bases: They are nonaqueous e.g. vegetable oils, animal fats, waxes, soft paraffin, hard paraffin, liquid paraffin etc.

2. Absorption bases: They are anhydrous but can absorb small quantity of water but still retain ointment like consistency. e.g. Wool fat, Lanolin, Wool alcohol, Beeswax etc.

3. Emulsion bases: They are either o/w or w/o type of emulsion and have cream like consistency. They (o/w) are washable with water. e.g. Emulsifying Ointment B.P., Cetrimide Emulsifying Ointment B.P.

4. Water soluble bases: This base is completely soluble in water. e.g. Polyethyleneglycols (PEG) also called Carbowax.

Preparation of ointment:

A well-made ointment is –

(a) Uniform throughout, i.e. it contains no lumps of separated high melting point ingredients of the base, there is no tendency for liquid constituents to separate and insoluble powders are evenly dispersed.

(b) Free from grittiness i.e. insoluble powders are finely subdivided and large clumps of particles are absent.

The ointments can be prepared by any of the following methods:

1. Trituration method

2. Fusion method

3. Chemical reaction method

4. Emulsification method

1. Trituration method:

This method is used when the drug is insoluble in the base and the base is soft.

(i) Solid ingredients are finely powdered in a mortar.

(ii) Required quantity of the ointment base is weighed .

(iii) The powders are taken on an ointment slab. Small amount of the base is taken on the solid powder and triturated with the flat side of a horn spatula until a uniform product is formed.

(iv) Remaining quantity of the base is added and mixed uniformly with the spatula.

Example: Sublimed sulfur, finely sifted 10g

Simple ointment 90g

2. Fusion method

When an ointment base contains a number of solid ingredients of different melting points, ointment is prepared by fusion method.

Method-I: The ingredients are melted according to the decreasing order of their melting points. First the highest melting point compound is melted in a beaker then the next melting point and so on. This method prevents the charring of the materials.

Method-II: all the ingredients mixed and melted at a time. In this case the overall melting range reduces.

Example:

Simple ointment

Wool fat 5g

Hard paraffin 5g

Cetostearyl alcohol 5g

White soft paraffin 85g

Cetrimide ointment

Cetrimide 1g

Cetostearyl alcohol 10g

White soft paraffin 10g

Liquid paraffin 29g

Purified water 50g

3 .Chemical reaction method:

Certain chemical reactions are involved in the preparation of several ointments.

Example-1: Ointments containing free iodine

Principle: Iodine is sparingly soluble in pure water. So a concentrated solution of potassium iodide is prepared and the iodine is dissolved in it. Iodine forms soluble complexes by reaction (KI.I₂, KI.2I₂, KI.3I₂ etc.)

Iodine 4g

Potassium iodide 4g

Wool fat 4g

Yellow fat 76g

Water 12g

Procedure:

(i) Potassium iodide is dissolved in water. Iodine is dissolved in the potassium iodide solution.

(ii) Wool fat, yellow soft paraffin are melted in a beaker on a water bath, cooled to about 40⁰C.

(iii) Iodine solution is added to the oil phase. Stirred until cool and stored in a glass jar.

Example-2: Non-staining iodine ointment

Principle: Fats and oils obtained from animal or plant sources often contain unsaturated fatty acids or their esters. The iodine combines with double bonds and thus free iodine is not available.

e.g. CH₃(CH₂)₇CH = CH(CH₂)₇COOH + I₂ ® CH₃(CH₂)₇CH.I – CH.I (CH₂)₇COOH

Oleic acid Di-iodostearic acid

Since free iodine is not available, these ointments are dark, greenish black in color. It leaves no stain when rubbed on the skin.

Iodine ointment, non-staining B.P.C.

Iodine 5g

Arachis oil 15g

Yellow soft paraffin q.s. 100g

Procedure:

(i) Iodine is powdered and shaken with arachis oil at room temperature until dissolved and the temperature of the solution is raised to 50⁰C, with stirring until the brown color disappears.

(ii) Sufficient amount of yellow soft paraffin, heated to 40⁰C, poured into the iodine solution. Mixed well and kept in a wide-mouthed ointment jar and left undisturbed to cool down.

4. Emulsification method

(i) In this methods the fats, oils and waxes are melted in a beaker at 70⁰C.

(ii) The aqueous phase is also heated to 70⁰C.

(iii) The aqueous solution is slowly added to the melted base. Stirred to cool down.

Emulsifiers used are:

for o/w type emulsion – water soluble soap

for w/o type emulsion – triethanolamine stearate soap, cetyl alcohol, Calcium soap of beeswax.

Containers of ointments: Wide mouthed, glass or plastic jar having screw caps or collapsible tubes may be used.

Labelling: FOR EXTERNAL USE ONLY

Storage: Stored in a cool place. Keep away from direct sunlight, temperature or direct heat source.

CREAMS

These are semi-solid emulsions for external use.

Classification of creams: (i) Aqueous cream (o/w type) (ii) Oily cream (w/o type)

They do not stain the skin.

Aqueous creams: The emulsion is o/w type. These creams are relatively non-greasy.

(a) Creams containing anionic emulsifying agent:

Emulsifiers: Anionic emulsifiers e.g. Emulsifying ointment

(b) Creams containing cationic emulsifying agent:

Emulsifiers: Cationic emulsifiers e.g. Cetyl trimethyl ammonium bromide (Cetrimide)

Emulsifiers: Monostearin, sorbitan esters (polysorbates), fatty alcohols (like stearyl alcohol)

Procedure:

(i) Oil phase containing oils, waxes are melted together at 70⁰C.

(ii) Aqueous phase containing water-soluble ingredients, emulsifying agents are dissolved in water and temperature is raised to 70⁰C on a water bath.

(iii) Aqueous phase is mixed to oil phase. Constantly stirred until cooled.

Oily creams: The emulsion is w/o type. These creams are greasy in nature.

(a) Sterol creams: Emulsifiers: – Woolfat, wool alcohol.

(b) Soap creams: Emulsifiers: – Triethanol amine soap, Borax soap.

Procedure:

(i) Oil phase containing oils, waxes and emulsifying agent are melted together at 70⁰C.

(ii) Aqueous phase containing water-soluble ingredients are dissolved in water and temperature is raised to 70⁰C on a water bath.

(iii) Aqueous phase is mixed to oil phase. Constantly stirred until cooled.

Containers: Wide mouthed, air-tight jars.

Label: FOR EXTERNAL USE ONLY, “Store in a cool place”

PASTES

Pastes are semi-solid preparations for external application . It contains high proportions of finely powdered drugs. They are very thick and stiff.

They form protective coating over the are on which applied.

Classification:

1. Hydrocarbon base: Soft paraffin and liquid paraffin.

2. Water miscible base: Glycerin, Emulsifying ointment

3. Water soluble base: High and low molecular weight polyethylene glycols (PEG 200, 400, 600, 4000, 6000 etc.)

Method of preparation:

(i) The base is melted in a beaker.

(ii) All the powders are sieved through #120 mesh and are taken in a mortar.

(iii) Small amount of base is triturated within a warm mortar to make a uniform paste.

(iv) Rest amount of the base is added and mixed.

Storage of the pastes: Pastes are stored in a well-closed jar or in a collapsible tube. The paste should be kept in a cool place.

Label: Apply with a spatula or a lint.

Difference between Paste and Ointment

Paste	Ointment
1. contains large amount of powdered solid (50% approx.) 2. Very thick and stiff. 3. Less greasy 4. Applied with a spatula or spread with a lint. 5. Forms a protective coating through which the moisture from the skin can escape.	1. May contain small amount of suspended particles. 2. Soft semisolid preparations. 3. More greasy 4. Applied on the skin without friction. 5. Forms an occlusive layer through which moisture cannot escape.

JELLIES

Jellies are transparent or translucent, non-greasy, semisolid preparations, generally applied externally. They are used for medication, lubrication and some miscellaneous applications.

Uses:

1. Medicated jellies: Soluble drugs like local anaesthetic and antiseptics are given in medicated jellies. When the water evaporates, it gives a cooling sensation and a thin film is left over the skin that adheres well. It is easily removed by washing with water.

2. Lubricant jellies: Catheters, rubber gloves or finger stalks used for rectal examination require lubrication before use. The jelly must be sterile for inserting in side the body such as bladder. In painful investigation, the jelly may contain local anaesthetic.

3. Miscellaneous jellies: Patch testing of some allergens and in electro-cardiography.

Formulation:

1. Gelling agents: Tyragacanth, sodium alginate, pectin, starch, gelatin, Methyl cellulose, Hydroxypropylmethyl cellulose, Carbopol, Polyvinyl alcohol etc. All these gelling agents are hydrocolloid in nature. They bind the free water and thus make the system viscous.

2. Preservatives: All jellies, because of their water content, grows microorganisms, hence a suitable preservative is used. E.g. Methyl hydroxybenzoate (Methyl paraben), Propyl hydroxy benzoate (Propyl paraben), Benzoic acid, Benzalkonium chloride, Chlorhexidine acetate etc.

3. Hygroscopic substances: To prevent rapid loss of water from the jellies a hygroscopic agent is added. E.g. Glycerol, Propylene glycol, sorbitol etc.

4. Chelating agents: Bases sensitive to heavy metal ions are saved by adding some chelating agents like EDTA (Ethylene diamine tetra acetate) to chelate the heavy metal ions.

Preparation: Preparation of jelly with cellulose derivatives like, Sodium carboxymethyl cellulose, methyl cellulose etc.

(i) The preservative (dissolved in alcohol) and any other water-soluble ingredients are dissolved in water and heated to 70⁰C.

(ii) Jelling powder is added in small quantity to the hot water and dispersed. Stirred to cooling.

(iii) When the solution is cooled the powder will form jelly.

(iv) The jelly is transferred in to a collapsible tube.

Container: Jellies are packed in collapsible tubes

Storage: Stored in cool place to prevent drying.

Example:

Ichthammol jelly

Ichthammol 2g

Tragacanth, in powder 5g

Alcohol (90%) 10ml

Glycerol 2g

Water, q.s. 100g

Lubricating jelly

Sodium carboxymethyl cellulose 5g

Glycerol 15g

Methyl hydroxyparaben 0.1g

Patent Blue V 0.001g

Purified water q.s. 100g

SUPPOSITORIES

Definition:

Suppositories are conical or ovoid, solid preparations for insertion in to the rectum where they melt, dissolve or disperse and produce a local or a systemic effect.

The suppositories generally weigh 1, 2 or 4g.

Types of suppository bases:

1. Fatty bases – these melt at body temperature. E.g. cocoa butter (i.e. theobroma oil).

2. Water soluble or water miscible bases: – these dissolve or disperse in rectal secretion, e.g. Glycero-gelatin base, and Polyethylene glycol base (PEG 400, 1000, 4000, 6000 etc.)

Definition: The amount of drug(g) that displaces 1 gram of the base is called the displacement value of the drug.

The displacement value is constant for a drug and a base.

Mathematical expression: Displacement value of a drug

Preparation of cocoa butter suppositories:

1. Lubrication of moulds: The moulds cleaned are lubricated by aqueous lubricant (Soft soap + glycerol + alcohol). After lubrication the moulds are kept inverted to drain out excess lubricant.

2. Melting of the base: The cocoa butter is weighed and grated with a spatula and taken in a beaker and heated on a water bath. When about 2/3 portion of cocoa butter oil was melted the beaker was taken out of the water bath and the solid residue was mixed and melted with a spatula. [N.B. Over heating may occur if the base is left over the heat until completely melted.]

3. About half of the melted base was taken on to the powdered drug on the ointment tile and levigated with the spatula to mix it smoothly. When the base was solidified, it was softened by holding the tile over the water bath for few seconds.

4. The dispersion was transferred in the beaker again and stirred gently to form a homogeneous mixture. Stirring was continued until the mixture begins to thicken. The cavities of the mould were filled up with the dispersion. The mould was left for two to three minutes until the mass had just set in then the mould was scrapped with a sharp knife. The mould was left in a cool place for 10 to 15 minutes. Then the mould was opened and suppositories were removed.

Preparation of glycero-gelatin suppositories:

Glycero-gelatin base is 1.2 times more denser than cocoa-butter base. To get the displacement value of a drug for glycero-gelatin base the following formula can be used:

Displacement value of a drug in glycero-gelatin base

1. The moulds are cleaned and lubricated with either liquid paraffin or arachis oil. The mould is kept in inverted position.

2. Glycerol is heated to 100⁰C on a water bath.

3. In another beaker water soluble ingredients (thermostable) are dissolved and heated on another water bath. Gelatin is added to water to wet the material. Gelatin is added to water with gentle stirring. Heated on a boiling water bath until all the gelatin goes into solution.

4. The beaker is weighed and water is either evaporated or more water is added to make up the volume.

5. The molten mass is poured into the moulds and chilled in a refrigerator.

Container: Each suppository is packed in thin aluminium foil and placed inside partitioned, rigid paper boxes. Hygroscopic suppositories such as glycero-gelatin suppositories should be placed in airtight jars.

Label: ‘Store in a cool place only’, ‘FOR RECTAL USE ONLY’

POWDERS

Definition: Powders are solid dosage form of medicament in which the drugs are dispensed in a finely divided state.

Classification: 1. Bulk powder for internal use

2. Bulk powder for external use, e .g. dusting powders and insufflations.

3. Divided powders (i.e. single dose)

1. Bulk powder for internal use

Preparation:

Whenever several powder ingredients are present the powders are mixed in ascending order of bulk in a mortar. At each addition, a quantity that is approximately equal the bulk already existed in the mortar is added.

Example:

Compound Calcium Carbonate Powder

Sodium bicarbonate 37.5g

Calcium carbonate 37.5g

Heavy Magnesium carbonate 12.5g

Light Kaolin 12.5g

Compound Sodium Chloride & Dextrose Powder

Sodium chloride 0.50g

Potassium chloride 0.75g

Sodium carbonate 0.75g

Dextrose 20.0g

Container: Kept in a well-closed, air tight container.

Mode of use: Prescribed amount is dissolved in required amount of water and taken orally.

2. Bulk powder for external use

Classification:

A. Dusting powder (a) Medical powder (b) Surgical dusting powder

B. Insufflations

C. Dentrifices (tooth powder)

A(a) Medical dusting powder

These are used for superficial skin conditions. They are not sterile. They are not applied on open wounds or broken skin.

Ingredients: Purified Talc, Light kaolin, Starch etc. They contain powdered drugs. Talc, kaolin are mineral ingredients. They may be contaminated with spores of Clostridium tetani and Clostridium welchii. So talc or kaolin must be sterilized by heating at 160⁰C for one hour.

Preparation:

After mixing the powders in a mortar it passed through a mesh no. 120 to remove gritty particles. Then it is packed in a suitable container.

Container: Dusting powder is packed inside a sifter-top container. (It is a container with holes in the cap. Whenever the container is shaken the powders are spread on the skin.)

Example:

Starch salicylic acid dusting powder

Starch, in powder 75g

Zinc oxide 20g

Salicylic acid, in powder 5g

Dicophane dusting powder

A(b) Surgical dusting powder

These are used in body cavities and major wounds, on burns and on the umbilical cords of newborns, hence they must be sterile.

They often contain an antibacterial agent and the diluent may be sterilized maize starch.

Example: Chlorhexidine B.P.C., Hexachlorphane B.P.C.

B. Insufflations

Finely divided powders intended for application to body cavities such as tooth socket, ears, nose, vagina and throat are known as insufflations. N apparatus is used to deliver a stream of finely divided powder particles to the site of application is called an insufflator.

They are used to produce either –

(a) a local effect, as in the treatment of ear, nose and throat infections with antibiotics, or

(b) a systemic effect, from a drug that is destroyed in the intestine.

The diluent used in nasal mucosa is lactose and used on open wound is sterilizable maize starch.

Container: Well-closed container supplied with an insufflator instrument.

The required dose of powder is taken in the container of the insufflator and with the bulb a pressure is given to force the powder through the nozzle.

Storage: With moisture the nozzle of the insufflator may get choked hence., the powder must be kept in a dry place and in a well closed container.

C. Dentifrices (tooth powders)

Powders used to clean the teeth are called dentifrices. It is applied with a tooth brush. They contain

(i) a suitable detergent – hard soap powder

(ii) a suitable abrasive agent – calcium sulfate, magnesium carbonate, dibasic calcium phosphate

(iii) Sweetening agent – sodium saccharin

(iv) Flavoring agent – peppermint oil, clove oil etc.

Packaging: Sifter top metallic or plastic container.

3. Divided powders (i.e. single dose)

In this form of powder, each dose is separately enclosed in a piece of paper.

Classification:

(a) Simple powder: Contains only one ingredient.

(b) Compound powder: Contains more than one ingredient.

The total amount in each dose should not be less than 120mg so that the powder is large enough to be handled conveniently.

Packing:

(1) For wrapping divided powders, white glazed paper (demy paper) is generally used.

(2) The powder wrappers are stacked in a paper box and dispensed.

(3) Some time double wrapping is required, especially if the powder is hygroscopic. In this case waxed paper is used as inner wrapper, then the demi wrapper as the outer wrapper.

General method of preparation of powders:

1. Spatulation: If the solids form eutectic mixture, they form liquid on trituration. In this case they should be mixed lightly with a spatula.

2. Trituration: The solids are taken in a mortar and triturated with a pestle. This method reduced the particles and at the same time mixes the powders.

3. Geometric dilution: This method is used when very small amount of potent drug is to be mixed with large amount of diluent. The method can be explained with an example:

For example, say 100mg of a potent drug (A) is to be mixed with 900mg of diluent (B), then the geometric dilution method is as follows:

(i) 100mg A + 100mg B ® 200mg mixture

(ii) 200mg mixture + 200mg B ® 400mg mixture

(iii) 400mg mixture + 400mg B ® 800mg mixture

(iv) 800mg mixture + rest of B ® 1000mg mixture

CAPSULES

Capsules are oral unit dosage forms in which the drug is enclosed in a water soluble hard gelatin shell. Capsules are made of gelatin.

Classification: A. Hard gelatin capsules B. Soft gelatin capsules

Hard gelatin capsule shell number: Larger ¬ 000, 00, 0, 1, 2, 3, 4, 5 ® Smaller

METHODS OF FILLING OF HARD GELATIN CAPSULES:

Method-I:

(i)

All the powders are mixed together by trituration in a mortar (either in ascending order of mixing or by geometric dilution method).

(ii) The powder mixture is taken over a glazed tile and spread with a spatula so that the height of the powder bed is 1/3^rd the height of the base of the capsule shell.

(iii) The base of a capsule is held within thumb and index finger and the open end is pressed on the powder bed. It is pressed until filled and the weight is taken. This method is carried out until the capsule gains required weight.

(iv) The cap is closed. Similarly all the capsules are filled and then they are polished with a clean piece of cloth.

Method-II:

(i)

All the powders are mixed together by trituration in a mortar (either in ascending order of mixing or by geometric dilution method).

(ii) The powder mixture is heaped on a glazed tile. The base of the capsule is held on its side and the powder is pushed with the spatula until required weight of powder is filled.

(iii) The cap is closed. Similarly, all the capsules are filled and then they are polished with a clean piece of cloth.

Method-III

A simple capsule filling apparatus can be used. It consists of a plastic block (A) with rows of cavities that hold the capsule base. A plastic bridge (B) contains a row of holes corresponding to the rows of cavities. The powder is poured into the capsule base with the help of a long stem funnel so that the end of the funnel can pass into the mouth of the capsule below.

The capsule bases are placed into the cavities. A funnel is passed through the hole into the capsule base. Weighed amount of powder is passed down into the capsules. A thin glass or plastic rod is used to push the powder into the capsule. The cap of the capsule is placed over the base and locked.

Difference between hard gelatin capsule and soft gelatin capsule

Hard gelatin capsule	Soft gelatin capsule
1. The hard gelatin capsule consists of two parts:- (a) Body and (b) Cap	1. The soft gelatin capsule becomes a single unit after sealing the two halves of the capsule.
2. They are cylindrical	2. They are available in round, oval and tube like shapes.
3. Hard gelatin capsule can contain powder or granules.	3. Soft gelatin capsule can contain liquid and semisolids.
4. They do not contain plasticizer.	4. They contain plasticizer like glycerol, propylene glycol.

Containers of capsule

Capsules should be dispensed in tightly closed container. A silica gel bag is provided in very humid condition.

Storage: Capsules should be stored below 30⁰C. The capsules may contain 12 to 16% moisture depending on the storage condition. When humidity is low, capsules become brittle and when humidity is high capsules become soft and loose their shape.

EFFERVESCENT POWDERS

Effervescent powders contains an acid (either tartaric acid or citric acid) and a base (sodium bicarbonate) – both are in dry condition. When this powder is dissolved in water the base reacts with acid to produce carbon dioxide. This carbon dioxide liberates very rapidly to produce effervescence.

The reaction is as follows:

Medicaments: Often inorganic salts containing water of crystallization are incorporated. e.g. magnesium and sodium sulfates, sodium phosphate and lithium citrate.

Sometimes saccharin or sucrose may be added as a sweetening agent.

Preparation:

Method-I: All the powders are mixed in dry condition in a mortar and packed in an air-tight container.

Method-II: Dry acid and base are packed separately in to two packets. The colors of the packets are different. Before use both the powders are added to water and when the reaction subsides (ends) the solution is taken.

Container: They may be packed as divided dose or may be packed in an air-tight, wide-mouthed bottle.

Storage: In presence of moisture both the acid and base reacts and carbon dioxide forms. To prevent this reaction the powders must be kept completely dry. This type of powders are packed in air-tight wide mouthed bottle.

TABLET TRITURATES

Definition: These are powders moulded into tablets. They are flat, circular discs, usually containing a potent drug mixed with a diluent. Diluent mostly used are lactose, sucrose and dextrose etc. Tablet triturates disintegrate very quickly in contact with water.

Apparatus: Triturate mould

The triturate mould is made of stainless steel, vulcanite or plastics. It consists of an upper plate containing holes and a lower plate containing equal number of pegs.

Preparation:

1. The drug and diluent are very finely powdered in a mortar.

2. A suitable liquid (60% alcohol) is added and mixed to form a stiff paste.

3. The upper plate is placed on a clean tile and the stiff paste is pressed into the holes with a spatula. The extra amount is scrapped off smoothly.

4. The filled plate is placed over the lower plate (with pegs) and pressed down. Well-formed tablets remain on the pegs. In this conditions the tablets are left for drying at room temperature for 1to 2 hours.

Packing:

In presence of moisture it may deteriorate, hence the tablets must be stored in air-tight container. The tablet triturates are soft, so they crush easily. So the tablets are packed in a single row in a barrow-tube sealed with a plug-type plastic closure.

Storage: The products are stored in a cool place.

Use: Used as oral tablets or hypodermic tablets.

LOZENGES (TROCHES)

These are solid preparations consisting mainly of sugar and gum. They are very hard and dissolve very slowly to slowly release the drug.

Use:

They are used to medicate the mouth and throat and for the slow administration of drugs for indigestion and cough.

Preparation:

(i) Compressed Lozenges: They are prepared by compression in a tablet punching machine. To increase the hardness of the tablet the following actions are taken:

(a) very high compression force is applied

(b) no disintegrant is added

(ii) Moulded Lozenges: The powdered drugs and diluents are mixed and the powder is mixed with binder and water to make a suitable plastic mass. The mass is rolled with a spatula and the roll is cut into equal size pieces. They are dried in hot air.

Container: Lozenges may soften in humid condition, so they must be packed in air-tight containers and kept in a dry and cool place.

PAINTS

Throat paints are viscous liquid preparations used for mouth and throat infections.

Glycerin is commonly used, because it is very viscous and it adheres well to the mucous membrane of mouth and throat. It also gives a sweet taste and warm sensation to the inflamed area.

Examples: Compound iodine paint (Mandl’s paint), boric acid glycerin, phenol glycerin, tannic acid glycerin.

Containers: Air-tight, colored, fluted bottle.

Labelling: “FOR EXTERNAL USE ONLY’

Storage: Stored in a cool place.

SPRAYS

Sprays are preparations of drugs in aqueous, alcoholic or glycerin containing media. They are applied to the mucosae of nose or throat with an atomizer or nebulizer.

Classification

(i) Throat Sprays (ii) Nasal Sprays

Throat Sprays

Use:

Solutions when sprayed with the help of atomizer (scent spray type) coarse droplets are formed. These droplets can reach upper respiratory tract and can be used to spray antibiotics in laryngitis, pharyngitis and tonsilitis.

Solutions when sprayed from nebulizer, finer droplets are produced, which can reach the lungs. They are used to spray bronchodilators (like sulbutamol, terbutaline etc.) in asthma or hay fever.

Formulation:

The solution is generally aqueous or alcoholic.

It contains antibiotics or bronchodilators.

After spraying droplets are formed. When these droplets are carried to the lungs, on the way they evaporates and the droplet size get reduced to a very small size, which is very easily exhaled out from the lungs. So to reduce evaporation glycerin or propylene glycol is added to the solution.

Container: Fluted, narrow-mouthed, light-resistant, screw-capped bottle. A nebulizer or atomizer is provided.

Label: “Store in a cool place”

Instruction: The patient is instructed about the use of atomizer or nebulizer.

Nasal Sprays

Use: Nasal sprays are used to reduce nasal congestion and to treat infections.

Formulation: Nasal decongestant is used like oxymetazoline hydrochloride spray, nafazoline spray etc.

Container: The droplets must retain in the nasal tract hence the droplets size must be bigger. So a atomizer or a

squeeze bottle spray is used.

INHALATIONS

These are liquid preparations containing volatile substances.

Use: They are used to relieve congestion and inflammation of the respiratory tract.

Formulation:

Type-I: Pure ingredients

Some ingredients are volatile at room temperature and may be inhaled from handkerchief .

Others are added to hot, but not boiling (65⁰C) and the vapor is inhaled for about 10minutes.

Type-II: Solution of ingredient or volatile substances adsorbed on magnesium carbonate dispersion.

These solutions or dispersions are added to hot, but not boiling (65⁰C) water and the vapor is inhaled for about 10minutes

Volatile ingredients: Camphor, Menthol, Thymol, Turpentine oil, Eucalyptus oil etc.

Container: Narrow mouthed, Screw-capped, colorless, fluted bottle.

Label: ‘Keep the bottle tightly closed’

POULTICE

Definition: Poultices are paste like preparations used externally to reduce inflammation. After heating, the preparation is spread thickly on a dressing and applied, as hot as the patient can bear (endure) it, to the affected area.

Formulation: Poultice must retain the heat for a considerable time because they are intended to supply warmth to the inflamed parts of the body.

Example: Kaolin Poultice B.P.C.

Heavy kaolin 50%w/w

Glycerol 40%w/w

Thymol

Boric acid

Peppermint oil

Methyl salicylate

Produces a thick paste. Low cost.

Produces the paste. Have good heat capacity

Powerful bactericide

Weak antimicrobial agent

Odor

Anti-inflammatory

Preparation:

(i) Heavy kaolin is heated on a aluminium tray to 100⁰C to dry completely, cooled and passed through mesh #180.

(ii) Boric acid is sieved and mixed with the kaolin in a mortar and triturated with glycerol to form a smooth paste.

(iii) The paste is transferred to a wide mouthed glass jar. Mouth is closed with a aluminium strip or a paper. The jar is heated at 120⁰C for 1 hour to kill any bacterial spore that may be present in the kaolin.

(iv) After cooling the volatile ingredients are added and stirred thoroughly.

(v) The jar is closed tightly to prevent moisture absorption (glycerol absorbs moisture) and loss of volatile substances.

QUESTIONS

For final examination

Q1. Give two examples each of diffusible and indiffusible solids.

Q2. How will you prepare a mixture containing indiffusible solids?

Q3. How will you dispense the following formulae:

Compound benzoin tincture

Benzoin Tincture

Lobelia ethereal tincture

Myrrh tincture

Tolu Tincture

Precipitated sulfur

Alcohol 95%v/v

Glycerol

Quillaia Tincture

Calcium hydroxide solution

Q4. Give one example of a suspension prepared by chemical reaction. Give the method of preparation of that suspension.

Q5. Classify emulsion. Give the identification tests of emulsion.

Ans: Classification of emulsion: (A) Simple emulsion – (i) o/w type and (ii) w/o type

(B) Multiple emulsion – (i) o/w/o type (ii) w/o/w type

Identification test:

The following tests are done to distinguish between o/w and w/o type emulsions.

Test	Method	Observation	Inference
Miscibility test	Emulsion is taken in a beaker and small volume of water is added to it.	The water mixes with the emulsion The water remains separate.	o/w type w/o type
Dye test	Scarlet red (oil soluble) is mixed with the emulsion and a drop of it is placed on a microscopic slide and viewed under microscope.	Droplets are red, background is colorless Droplets are colorless, background is red.	o/w type w/o type
Conductivity test	A pair of electrodes are dipped in an emulsion and the electrodes are connected to a battery, a bulb and a switch. The switch is put on.	The bulb glows. The bulb did not glow.	Water conducts electricity, so o/w w/o
Fluorescence test	A drop of emulsion is placed on a slide, placed under UV light, and observed through a microscope.	Fluorescent dots Background is fluorescence	Oils fluoresce in UV light o/w type w/o type
CoCl₂ / filter paper test	Filter paper impregnated with CoCl₂ and dried (blue). A drop of emulsion is taken on it.	Color changed to pink Color unchanged (i.e. blue)	o/w w/o

Q6. Classify emulsifiers with one example each.

Q7. Give the difference between lotion and liniment.

Q8. Write short note on elixir.

Q9. Classify ointment bases with one example each.

Q10. How will you prepare the following formulae

Wool fat 5g

Hard paraffin 5g

Cetostearyl alcohol 5g

White soft paraffin 85g

Sublimed sulfur, finely sifted 10g

Simple ointment 90g

Text Box: Q16. Write short note on insufflation.
Q17. Distinguish (difference) between hard and soft gelatin capsules.
Q18. Write a short note on effervescent powder / granules.
Q19. Write a short note on tablet triturate.
Q20. Write a short note on lozenges.
Q21. Write a short note on sprays.
Q22. Write a short note on throat paints.
Q23. Write a short note on inhalations.
Q24. Write a short note on poultices.

Q11. What is the difference between creams and ointments?

Q12. What is the difference between paste and ointments?

Q13. How will you prepare lubricating jelly of the following formula:

Sodium carboxymethyl cellulose 5g

Glycerol 15g

Methyl hydroxyparaben 0.1g

Patent Blue V 0.001g

Purified water q.s. 100g

Q14. Define displacement value? How will you dispense cocoa butter suppositories each containing 200mg Zinc oxide? [Ans. See practical notes]

Q15. Classify powder with one example each.

DOWN LOAD-------ORIGINAL-------PRINCIPLES AND PROCEDURES OF DISPENSING PRESCRIPTATION

FOR PHARMACEUTICS THEORY

PRINCIPLES AND PROCEDURES OF DISPENSING PRESCRIPTIONS

Search This Blog

Principles and procedures of dispensing prescriptions

Preparation of suspensions

Preparation of suspension containing poorly wettable solids

For internal preparations (i.e. oral preparations): Polysorbates (Tween 80), alcohol, glycerol etc.

General method of preparation

EMULSIONS

Tests of identification of type of emulsion

Miscibility test

Dye test

Conductivity test

Finely divided solid particles

Synthetic Surface Active Agents

Vegetable source

Animal source

Synthetic

Colloidal clays:

Bentonite (aluminium silicate)

Anionic

Cationic

Ampholytic

Non-ionic

Method of preparation of emulsions

Formulation of syrups

ELIXIRS

LINCTUS

LINIMENT

LOTIONS

Compound Calcium Carbonate Powder

A(a) Medical dusting powder

A(b) Surgical dusting powder

B. Insufflations

C. Dentifrices (tooth powders)

Miscibility test

Dye test

Conductivity test

Fluorescence test

CoCl₂ / filter paper test

Search This Blog

Principles and procedures of dispensing prescriptions

Preparation of suspensions

Preparation of suspension containing poorly wettable solids

For internal preparations (i.e. oral preparations): Polysorbates (Tween 80), alcohol, glycerol etc.

General method of preparation

EMULSIONS

Tests of identification of type of emulsion

Miscibility test

Dye test

Conductivity test

Finely divided solid particles

Synthetic Surface Active Agents

Vegetable source

Animal source

Synthetic

Colloidal clays:

Bentonite (aluminium silicate)

Anionic

Cationic

Ampholytic

Non-ionic

Method of preparation of emulsions

Formulation of syrups

ELIXIRS

LINCTUS

LINIMENT

LOTIONS

Compound Calcium Carbonate Powder

A(a) Medical dusting powder

A(b) Surgical dusting powder

B. Insufflations

C. Dentifrices (tooth powders)

Miscibility test

Dye test

Conductivity test

Fluorescence test

CoCl2 / filter paper test

CoCl₂ / filter paper test