Pharmaceutical Excipients Lecture PDF

 Definition: Excipient is a pharmacologically inactive subs. formulated alongside The active pharmaceutical ingredient (API) of a medication. Purposes served by excipients: ⚫ Provide bulk to the formulation. ⚫ Facilitate drug absorption or solubility & other pharmacokinetic consideration...

 Definition: Excipient is a pharmacologically inactive subs. formulated alongside The active pharmaceutical ingredient (API) of a medication. Purposes served by excipients: ⚫ Provide bulk to the formulation. ⚫ Facilitate drug absorption or solubility & other pharmacokinetic considerations. ⚫ Aid in handling of “API” during manufacturing. ⚫ Provide stability and prevent from denaturation. No interaction with Pharmacologically drug inert. 3  Pharmaceutical Excipients used in pharmaceutical preparations Fillers Flavouring Agents Binders Colouring Agents Coating Agents Sweeting Agents Anti-adherent Disintegrants Preservatives Sorbents Antioxidants Glidants Lubricants 4 Typically fill out the size of a tablet or capsule, making it practical to produce & convenient for the consumer to use Function of fillers: Add volume and/or mass to a drug subs, so facilitating precise metering & handling in preparation of dosage forms. Used in tablets and capsules. Typical features of fillers: A good filler should be inert, compatible with the other components , Non- hygroscopic, relatively cheap, compactable, and preferably tasteless or pleasant tasting. 5 Example: Plant cellulose & Dibasic calcium phosphate, Lactose, Mannitol, Sorbitol, Calcium carbonate, and Magnesium stearate. Vegetable fats & oils are used in soft gelatine capsules.  Binders: Binders hold the ingredients in a tablet together. Binders ensure that tablets & granules formed with required mechanical strength, & give volume to low active dose tablets. Typical features of Binders: A Binder should be compatible with other constituents of formulation & add sufficient cohesion to the powders. Classification & examples: according to their application: 1.Solution binders dissolved in a solvent e.g.; water or alcohol 2. Dry binders added to powder e.g.; Cellulose, methyl cellulose, Polyvinyl pyrrolidone, and Polyethylene glycol. 7 Disintigrants are substance or mixture of substs. added to the drug formulations, which facilitate dispersion or breakup of tablets & contents of capsules into smaller particles for quick dissolution when it comes in contact with water in the GIT. Ideal properties of disintigrants: Good hydration capacity. Poor solubility and poor gel formation capacity. Examples: Polyvinylpyrrolidone, carboxymethyl cellulose, and sodium starch glycolate. 8 Coating is a process by which an essentially dry, outer layer of coating material is applied to the surface of a dosage form and agents used in this process are called coating agents. Types: 3 types of coating agents are used pharmaceutically: 1. Film coating. 2. Sugar coating. 3. Compression coating. Function of coating agents: Protection, Masking, Elegance, Ease of swallowing, and identification. 9 Sorbents are materials that soak up oil from the water. Types & examples of sorbents: Natural sorbents: peat moss, sawdust, feathers & anything else natural that contains carbon. Synthetic sorbents: polyethylene and nylon. Functions of sorbents: Used for tablet/capsule moisture-proofing by limited fluid. sorbing (taking up of a liquid or a gas by adsorption ) in a dry state. 10 Anti-adherents: Anti-sticking agents prevent adhesion of tablet surface to the die walls and the punches. Example: Water insoluble lubricants as Magnesium stearate, talc & starch used as ant adherents.  Lubricants prevent ingredients from clumping together and from sticking to the tablet punches or capsule filling machine. Lubricants also ensure that tablet formation & ejection occur with low friction between the solid and die wall. Types: 1. Hydrophilic lubricants: poor lubricants, no glidant or anti-adherent properties. 2. Hydrophobic lubricants : Most widely used today. Generally good lubricants & effective at low conc. Also have both anti- adherent & glidant properties. For these reasons, hydrophobic lubricants used much more frequently than hydrophilic. Example; magnesium stearate. 12 Roles of lubricants: 1.True Lubricant Role: To decrease friction at the interface between a tablet’s surface & die wall during ejection and reduce wear on punches. 2. Anti-adherent Role: Prevent sticking to punch faces or in case of encapsulation lubricants. Prevent sticking to machine dosator, tamping pins. 3. Glidant Role: Enhance product flow by reducing interparticle friction. Example of lubricants: Polyethylene glycol, Magnesium stearate, Stearic acid and its derivatives.  Glidants: A substance as colloidal silica that enhance the flow of a granular mixture by reducing inter-particle friction & used in the pharmaceutical production of tablets & capsule. Functions : Glidants used to promote powder flow by reducing interparticle friction & cohesion. Glidants used in combination with lubricants as they have no ability to reduce die wall friction. Example: Fumed silica, talc, & magnesium carbonate. 14  Preservatives: Substances that commonly added to various foods and pharmaceutical products in order to prolong their shelf life. Preservative system protect the product against microbial proliferation but does not compromise product performance. Ideal properties of preservatives: Preservative must exert a wide spectrum of antimicrobial activity at low inclusion levels. Preservative Maintain activity throughout product manufacture, shelf life and usage. Not compromise the quality or performance of product, pack or delivery system. Not adversely affect patient safety or tolerance of product. Examples: Methyl & Ethyl parabens, Propyl paraben, Benzoic acid & its salts, Sorbic acid and its salts. 15 An antioxidant is a molecule inhibits the oxidation of other molecules. Oxidation is a chemical reaction transfer electrons or hydrogen from a substance to an oxidizing agent. Ideal Properties of Antioxidants: Effective at a low, nontoxic conc. Stable & effective under normal conditions of use, over a wide pH and temprature range. Soluble at the required conc. Compatible with a variety of drugs & pharm. excipients. Free from objectionable odor and taste. Colorless in both the original and oxidized form. Nontoxic both internally & externally at the required conc. Unreactive (does not adsorb, penetrate, or interact) with containers or closures. Reasonable cost Examples: BHT( Butylated Hydroxy Toluene), BHA( Butyl Hyd Anisol), Sodium sulfite 16 Sweetening agents employed in liquid formulations designed for oral administration specifically to increase the palatability of the therapeutic agent. Example: Sucrose, Saccharine, Aspertame, Sorbitol. Uses of sweetening agent: The main agents employed in oral preparations are sucrose, liquid glucose, glycerol, sorbitol, saccharin sodium & aspartame. Aspartame is an artificial sweetening agent. The use of artificial sweetening agents in formulations is increasing. Thus, use of sugars in oral formulations for children and patients with diabetes mellitus must be avoided. 17 Flavoring agents are added to increase patient acceptance. The four basic taste sensations are salty, sweet, bitter, sour. Certain flavors used to mask these specific taste sensations. Examples: Clove oil, citric and syrup, glycerin, rose oil, orange oil, menthol. Coloring agents: The pharmaceutical ingredients that impart the preferred color to the formulation are called coloring agents. Two types of coloring agents: 1. Natural Coloring agents. 2. Synthetic coloring agents. 18