Pharmaceutics (20) Excipients used in Liquid Dosage Forms (Part 02) | Excipients | Pharmaceutics

Download "Solution Pharmacy" Mobile App to Get All Uploaded Notes, Model Question Papers, Answer Papers, Online Test and other GPAT Materials - https://play.google.com/store/apps/de... Excipients Used In the Formulation of Liquid Dosage Forms Liquid dosage forms in addition to drug substance also contain excipients which serve different and specialized pharmaceutical purposes in the formulation. These excipients in most cases are present in a greater proportion with regards to the drug substance as it forms the bulk of the formulation. It is, therefore, essential to ensure that all excipients used in the formulation of liquid dosage forms are physically and chemically compatible with the drug substance and every other component of the formulation. 1. Vehicles/ Solvents In liquid pharmaceutical formulations, vehicles are major components used as a base in which drugs and other excipients are dissolved or dispersed. Vehicles used in the formulation of liquid dosage forms may be aqueous (e.g., water, polyhydric alcohols, hydro-alcoholic solutions and buffers) or oily (e.g., vegetable or mineral oils, organic oily bases, emulsified bases etc). 2. Co-solvents Co-solvents are primarily liquid components often used to increase the water solubility of drugs which do not contain ionisable group(s) and whose solubility can thus not be increased by pH adjustment. Examples of excipients used as co-solvents include glycerol, propylene glycol, ethanol, the low molecular weight PEGs etc. 3. Surfactants Surfactants or surface-active agents are molecules with well-defined polar (hydrophilic) and non-polar (hydrophobic) regions that associate in aqueous media to form dynamic aggregates, known as micelles. Depending on the nature of the polar area, surfactants can be anionic (e.g., sodium dodecyl sulfate), cationic (e.g., trialkylammonium), zwitterionic (e.g., glycine and proteins) and nonionic (e.g., polyethylene glycol). Among these, the most commonly used ones are the anionic and non-ionic surfactants. 4. Preservatives Preservatives are chemical compounds that are added to formulations to protect them from microbial contamination. Among the acidic types are phenol, benzoic acid, boric acid, chloro-cresol, 9-phenyl phenol, alkyl esters of para-hydroxybenzoic acid, sorbic acid, and their respective salts. Neutral preservatives include chlorobutanol, benzyl alcohol, and beta-phenylethyl alcohol. 5. Viscosity modifiers/ Suspending agents Viscosity modifiers also known as suspending agents are excipients that minimize interparticle attraction and aggregation by functioning as energy barrier thus retarding particle settling. Common viscosity modifiers used in liquid pharmaceutical dosage forms include cellulose derivatives (e.g., methylcellulose, microcrystalline cellulose, carboxymethylcellulose, ethylcellulose, etc), clays (e.g., hectorite, bentonite, aluminium and/or magnesium silicate), natural gums (e.g., acacia, guar gum, tragacanth, xanthan gum, alginates, carrageenan and locust bean gum), synthetic polymers (e.g., carbomers, polyvinyl pyrrolidone, polyvinyl alcohol and poloxamer), Get in touch with the solution by just clicking the following links- Facebook Group-   / solutionpharamcy   Mobile App - https://play.google.com/store/apps/de... New Channel (Pharmacy Dictionary)    / @pharmacydictionary   E-Mail for official and other work - [email protected] #solutionpharmacy #Pharmacologyclass #Pharmacognosyvideos #GPAT