- Dosage form
- Dosage Forms classification
- Liquid Dosage form
Dosage form (DF) :- Is a pharmaceutical products involving a mixture of active drug components and non drug components in the form in which it is marketed for use.
Common dosage forms include pill, tablet, capsule, syrup, aerosol or inhaler, liquid injection etc.
The route of administration of drug delivery is dependent on the dosage forms of the substance.
Dosage Forms classification :-
1. Solid dosage forms
2. Liquid Dosage forms
3. Semi solid dosage forms
4. Aerosol
5. Sterile dosage forms
In this chapter we discussed about liquid Dosage form in detail.
Liquid Dosage form :-
• Liquid Dosage form commonly used in pharmacy are either monophasic or biphasic.
• Monophasic liquid Dosage form refers to liquid preparation in which there is only one phase.
• It is represented by true solution.
• A true solution is a clear homogeneous mixture that is prepared by dissolving a solid, liquid or gas in a liquid.
• The component of solution present in large amount is known as 'solvent' and the component present in small amount is known as 'solute'.
• Monophasic liquid Dosage form are classified into two group
1. Liquid means for internal administration for example mixture, syrup and elixir.
2. Liquid means for external administration for example gargle, mouthwash, throat paint, douches, nasal drops, ear drops, liniment and lotions.
• Liquid meant for internal administration :- Liquid preparation for internal administration include following categories of preparation :-
1. Mixture 2. Syrup 3. Elixir 4. Linctuses
• Mixture :- A mixture is a liquid preparation means for oral administration in which medicament or medicament are dissolved or suspend in a suitable vehicle.
• Generally several doses are dispensed in a bottle. In case a bottle contain one dose it is called draught.
• Mixture are not prepared to keep them for a long period because they are mainly prescribed for acute condition such as cough, indigestion, diarrhoea, constipation etc.
• So the mixture should be extemporaneously prepared and supplied only for small number of doses which can be used up within a short period. In case further need arises then a fresh mixture is prepared for the patient.
• Classification of mixture :- Mixture are classified into :-
1. Simple mixture containing soluble substance
2. Mixture containing diffusible solids
3. Mixture containing indiffusible soilds
4. Mixture containing precipitate forming liquid
5. Mixture containing slightly soluble liquids.
• Simple mixture containing soluble substance:- Simple mixture contains only soluble ingredients e.g. carminative Mixture, diarrhoea mixture and expectorant mixture.
• Method of dispensing :-
1. Dissolve the solid substance in 3/4 of the vehicle.
2. Examine the solution critically by holding it against the light. If foreign particle are visible, strain it through a cotton wool
3. Add any liquid ingredients.
4. Add more of vehicle to produce the final volume.
5. Transfer the mixture into the bottle. Cork it and then throughout polish the bottle to remove finger print. Attach the label wrap the bottle and dispense.
Example :- Prepare and dispense 90 ml of the following mixture.
Rx,
Potassium bromide 4.0 g
Tincture nux vomica 4.0 ml
Chloroform water. Add upto 90 ml
Direction :- One tablespoonful to be taken three times after males.
Method :- Dissolve potassium bromide in ¾ of chloroform Water. Filter the solution to remove foreign particle. Add tincture nux vomica. Incorporate more of chloroform Water to make required volume. Transfer the mixture to a bottle. Cork, labels and dispense.
• Mixture containing diffusible solids :- Diffusible solid are those which do not dissolve in water, but may be mixed there with so that upon shaking, the powder drug is evenly diffused throughout the liquid for sufficient time to ensure uniform distribution in each dose.
• The commonly used diffusible drug are bismuth carbonate, bismuth subnitrate , Magnesium carbonate, Magnesium oxide, quinine sulphate etc.
• Method of dispensing :-
1. Finely powder the drug in a mortar. Add any soluble drug and mix.
2. Measure ¾ of the vehicle. Make a smooth cream by using a portion of the vehicle and then add the remaining portion of the measured vehicle.
3. Transfer the content of mortar into a measure. Rinse the mortar with a little of vehicle and transfer it into a measure.
4. Add any liquid ingredient.
5. Add more of vehicle to produce the required volume.
6. Transfer the mixture to the dispensing bottle, cork , label and dispense. Apply the secondary labels “ Shake the bottle well before use”.
Example Prepare and dispense the following mixture.
Rx,
Magnesium sulphate 15.0 g
Magnesium carbonate 2.0 g
Peppermint water add upto 90 ml
Prepare a mixture.
Direction :- One tablespoonful to be taken two hours before breakfast.
Method :- Mix the required quantity of magnesium sulphate and magnesium carbonate in a mortar. Measure the ¾ of the peppermint water. Add the small quantity of it to the powder. Trituration thoroughly so as to form a smooth cream. Then add the remaining quantity of peppermint water. Strain through a muslin piece if foreign particle are present. Incorporate more of peppermint water to produce the final volume. Transfer the mixture to a bottle, cork and label.
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