MIXTURESMIXTURES

MIXTURESMIXTURES

Mixtures are fluid preparations intended for Mixtures are fluid preparations intended for internal administration.internal administration.

Simple Mixture: if the solute is soluble in the Simple Mixture: if the solute is soluble in the vehicle (large fluid component of the mixture).vehicle (large fluid component of the mixture).

Compound Mixture: if the solute is insoluble or Compound Mixture: if the solute is insoluble or dispersed in the vehicle.dispersed in the vehicle.

Mixtures are used in acute cases such as cough, Mixtures are used in acute cases such as cough, indigestion, diarrhea, constipation for which indigestion, diarrhea, constipation for which short period of treatment is adequate.short period of treatment is adequate.

Classification of MixturesClassification of Mixtures

A. Simple mixtures.A. Simple mixtures.

B. Mixtures containing insoluble diffusible solids.B. Mixtures containing insoluble diffusible solids.

C. Mixtures containing insoluble in-diffusible solids.C. Mixtures containing insoluble in-diffusible solids.

D. Mixtures containing slightly miscible liquids.D. Mixtures containing slightly miscible liquids.

E. Mixture containing precipitate forming liquids.E. Mixture containing precipitate forming liquids.

F. Miscellaneous mixtures. F. Miscellaneous mixtures.

Simple MixturesSimple Mixtures

Those preparations containing soluble Those preparations containing soluble ingredients e.g Iron Ammonium Citrate Mixture ingredients e.g Iron Ammonium Citrate Mixture (used in case of iron deficiency)(used in case of iron deficiency)

R/R/Iron ammonium citrate……………. 0.3 gmIron ammonium citrate……………. 0.3 gm

Tr. Nux Vomica……………………...0.1 mlTr. Nux Vomica……………………...0.1 ml

Spirit Chloroform…………………….0.1 mlSpirit Chloroform…………………….0.1 ml

Aqua ad. …………………………… 30 mlAqua ad. …………………………… 30 ml

Fait Mixture, Mitte iiFait Mixture, Mitte ii

Sig. Fl.oz T.D.S.Sig. Fl.oz T.D.S.

N.B. Tincture Nux Vomica is tonicN.B. Tincture Nux Vomica is tonic

Simple MixturesSimple Mixtures

PROCEDURE:PROCEDURE:Calculate the required weight and volume.Calculate the required weight and volume.Dissolve iron ammonium citrate in ¾ of the Dissolve iron ammonium citrate in ¾ of the vehicle volume, noting that iron ammonium vehicle volume, noting that iron ammonium citrate is added to vehicle and not the reverse.citrate is added to vehicle and not the reverse.Measure the liquid ingredients and add to iron Measure the liquid ingredients and add to iron ammnium citrate solution.ammnium citrate solution.Complete the volume to 60 ml with water.Complete the volume to 60 ml with water.Transfer to clean dry glass bottle and affix the Transfer to clean dry glass bottle and affix the label.label.

Simple MixturesSimple Mixtures

General Notes:General Notes:If solution is If solution is turbidturbid, filter through cotton wool., filter through cotton wool.If If large crystalslarge crystals are used, such as sodium sulphate are used, such as sodium sulphate crystals, it should be powdered and dissolved in mortar.crystals, it should be powdered and dissolved in mortar.Scale solidsScale solids must be crushed on paper and added to must be crushed on paper and added to vehicle in a beaker.vehicle in a beaker.To facilitate the work of a dispenser, To facilitate the work of a dispenser, stock solutionstock solution of of commonly used soluble chemicals are often prepared (in commonly used soluble chemicals are often prepared (in conc. Of 25% w/v).conc. Of 25% w/v).

Hygroscopic solidsHygroscopic solids ( (CaClCaCl22 and MgCl and MgCl22) are best kept in ) are best kept in solution. solution. The use of The use of hot waterhot water hasten dissolution of slowly soluble hasten dissolution of slowly soluble solids (e.g. borax)solids (e.g. borax)

B. Mixtures Containing Insoluble B. Mixtures Containing Insoluble Diffusible SolidsDiffusible Solids

Mixtures containing insoluble ingredients Mixtures containing insoluble ingredients that diffuse readily in the vehicle by that diffuse readily in the vehicle by shaking the bottle and remain dispersed shaking the bottle and remain dispersed long enough so that a dose can be poured long enough so that a dose can be poured out.out.A (Shake The Bottle) label A (Shake The Bottle) label mustmust be used. be used.Examples; magnesium carbonate, light Examples; magnesium carbonate, light kaolin, magnesium trisilicate, bismuth kaolin, magnesium trisilicate, bismuth sulphate and bismuth carbonate sulphate and bismuth carbonate

B. Mixtures Containing Insoluble Diffusible B. Mixtures Containing Insoluble Diffusible SolidsSolids

WHITE MIXTUREWHITE MIXTURE::

R/R/

Magnesium sulphate ……………4 gmMagnesium sulphate ……………4 gm

Magnesium carbonate (light)……2 gmMagnesium carbonate (light)……2 gm

Peppermint water ad………….....30 mlPeppermint water ad………….....30 ml

Fait Mixture, Mitte ii (60 ml)Fait Mixture, Mitte ii (60 ml)

Sig., two table spoonful to be taken half Sig., two table spoonful to be taken half an an hour before breakfasthour before breakfast

- Used as laxative.- Used as laxative.

B. Mixtures Containing Insoluble Diffusible B. Mixtures Containing Insoluble Diffusible SolidsSolids

Procedure:Procedure:1. Dissolve magnesium sulphate in about 30 ml of 1. Dissolve magnesium sulphate in about 30 ml of

peppermint water.peppermint water.2. In dry clean mortar triturate magnesium 2. In dry clean mortar triturate magnesium

carbonate (light) to a smooth past with a little of carbonate (light) to a smooth past with a little of vehicle, transfer to a measuring cylinder with vehicle, transfer to a measuring cylinder with successive portions of the vehicle.successive portions of the vehicle.

3. Add to the magnesium carbonate suspension 3. Add to the magnesium carbonate suspension the prepared magnesium sulphate solution with the prepared magnesium sulphate solution with stirring, and complete to volume with vehicle.stirring, and complete to volume with vehicle.

4. Transfer to white glass bottles and affix the label 4. Transfer to white glass bottles and affix the label together with shake the bottle label.together with shake the bottle label.

C. Mixtures Containing Insoluble C. Mixtures Containing Insoluble In-diffusible SolidsIn-diffusible Solids

Those mixtures containing insoluble solids that Those mixtures containing insoluble solids that settle down very rapidly and not remain evenly settle down very rapidly and not remain evenly distributed in the vehicle long enough to ensure distributed in the vehicle long enough to ensure uniformity of the measured dose.uniformity of the measured dose.They required a suspending agent.They required a suspending agent.As a general rule, the suspending agent ordered As a general rule, the suspending agent ordered by the prescriber should be used, when no by the prescriber should be used, when no suspending agent is ordered, the dispenser must suspending agent is ordered, the dispenser must select the most suitable one for a particular select the most suitable one for a particular solid.solid.

C. Mixtures Containing Insoluble In-C. Mixtures Containing Insoluble In-diffusible Solidsdiffusible Solids

Suspending Agents:Suspending Agents:These are substances included to keep insoluble These are substances included to keep insoluble medicament(s) in a state of suspension at least medicament(s) in a state of suspension at least sufficiently long for a dose to be poured out of the sufficiently long for a dose to be poured out of the container.container.

1. Gum Acacia Powder:1. Gum Acacia Powder:

- mixed with substance to be suspended before- mixed with substance to be suspended before adding the vehicle adding the vehicle

- used in concentration of 6-10% w/v of the mixture- used in concentration of 6-10% w/v of the mixture

C. Mixtures Containing Insoluble In-diffusible C. Mixtures Containing Insoluble In-diffusible SolidsSolids

Suspending Agents (cont.)Suspending Agents (cont.)

2. Gum Tragacanth powder:2. Gum Tragacanth powder:

- it usually make lumps when vehicle is added to- it usually make lumps when vehicle is added to it, so it is better to use it a mucilage. it, so it is better to use it a mucilage. - used in concentration of 0.25-2.3% w/v.- used in concentration of 0.25-2.3% w/v.- used only when ordered by the prescriber.- used only when ordered by the prescriber.

C. Mixtures Containing Insoluble In-diffusible C. Mixtures Containing Insoluble In-diffusible SolidsSolids

Suspending Agents (cont.)Suspending Agents (cont.)

3. Compound Tragacanth Powder:3. Compound Tragacanth Powder:- It consists of tragacanth powder, acacia powder, It consists of tragacanth powder, acacia powder,

starch and sucrose.starch and sucrose.- Starch grains prevent formation of lump.Starch grains prevent formation of lump.- Mixed with substance to be suspended in the Mixed with substance to be suspended in the

mortar and vehicle is added gradually with mortar and vehicle is added gradually with trituration.trituration.

- Used in concentration of 2% w/v of the mixture.Used in concentration of 2% w/v of the mixture.- Usually used when no particular suspending Usually used when no particular suspending

agent is orderedagent is ordered- Disadvantage; starch impart opacity to the final Disadvantage; starch impart opacity to the final

mixture.mixture.

C. Mixtures Containing Insoluble In-diffusible SolidsC. Mixtures Containing Insoluble In-diffusible Solids

Suspending Agents (cont.)Suspending Agents (cont.)

4. Mucilage of Acacia or Tragacanth4. Mucilage of Acacia or Tragacanth

used in concentration of 25% of final volumeused in concentration of 25% of final volume

Disadv: form solid mass with some insoluble Disadv: form solid mass with some insoluble solid e.g. bismuth saltssolid e.g. bismuth salts

R/R/Prepared chalk…………….0.6 gmPrepared chalk…………….0.6 gmTincture of catechu………..0.3 mlTincture of catechu………..0.3 mlGlycerin…………………….1.0 mlGlycerin…………………….1.0 mlChloroform water to……….15 mlChloroform water to……….15 mlPrepare mixture, send 10 dosePrepare mixture, send 10 dose

N.B. prepared chalk (calcium carbonate) is N.B. prepared chalk (calcium carbonate) is insoluble in-diffusible solid.insoluble in-diffusible solid.This formula is used as antacid.This formula is used as antacid.

Calculation of the amount of suspending agent:Calculation of the amount of suspending agent:

If no suspending agent is ordered we usually If no suspending agent is ordered we usually use the compound tragacanth powder in 2% use the compound tragacanth powder in 2% concentration. concentration.

15 X 15 X 2 2 = 0.3 gm for each dose = 0.3 gm for each dose

100100

So, for 10 doses = 0.3 gm X 10 = 3 gmSo, for 10 doses = 0.3 gm X 10 = 3 gm

D. Mixtures Containing Slightly D. Mixtures Containing Slightly miscible liquidsmiscible liquids

ExampleExample

R/R/

Creasote………………. 0.3 mlCreasote………………. 0.3 ml

Sodium benzoate…….. 0.3 gmSodium benzoate…….. 0.3 gm

Syrup tolu……………… 2.0 mlSyrup tolu……………… 2.0 ml

liquid extract of liquorices….2.0 mlliquid extract of liquorices….2.0 ml

Camphor water ad……….. 30.0 mlCamphor water ad……….. 30.0 ml

Fait Mistura, Mitte iiFait Mistura, Mitte ii

D. Mixtures Containing Slightly miscible D. Mixtures Containing Slightly miscible liquidsliquids

Procedure:Procedure:1.1. Calculate the weight and volumes enough to make 60 Calculate the weight and volumes enough to make 60

ml.ml.2.2. Dissolve sodium benzoate in about 10 ml of camphor Dissolve sodium benzoate in about 10 ml of camphor

water, add other liquid ingredients (syrup tolu and water, add other liquid ingredients (syrup tolu and liquorices).liquorices).

3.3. In a clean dry mortar triturate 1.2 gm of compound In a clean dry mortar triturate 1.2 gm of compound tragacanth powder (2% w/v) with about 10 ml of tragacanth powder (2% w/v) with about 10 ml of camphor water.camphor water.

4.4. Creasote is added dropwise to the gum mucilage with Creasote is added dropwise to the gum mucilage with continuous trituration.continuous trituration.

5.5. Transfer to cylinder containing the solution of step 2, Transfer to cylinder containing the solution of step 2, and complete volume to 60 ml with camphor water.and complete volume to 60 ml with camphor water.

E. Mixtures Containing Precipitate E. Mixtures Containing Precipitate Forming LiquidsForming Liquids

Spirit (for example) is an alcoholic solution of Spirit (for example) is an alcoholic solution of volatile liquid.volatile liquid.On dilution of spirits with water, they yield a fine On dilution of spirits with water, they yield a fine precipitate (ppt).precipitate (ppt).In the finally divided state the ppt is more easily In the finally divided state the ppt is more easily dissolved by the vehicle than in case if it was dissolved by the vehicle than in case if it was added directly to it.added directly to it.As a rule, it is necessary to shake until the As a rule, it is necessary to shake until the precipitated substance is dissolved.precipitated substance is dissolved.