Excipients Used in Pharmaceutical Compounding Preparations require excipients to impart a variety of properties to the compounded dosage form. From the compounder’s viewpoint, it is prudent to understand the role of each ingredient in the completed preparation. Many times this insight may alert the compounder to potential instabilities that might occur, clues about the preparation’s performance that would be useful/necessary to share with the patient, or provide alternatives if the preparation is not suitable for a patient due to allergies, preferences, etc. Also, excipients have different roles in different preparations, or oftentimes an excipient will play more than one role in a preparation. The list below is a compilation from several reference sources. It is not an all-inclusive list, nor does it provide an absolute classification scheme for all the excipients used in compounded preparations. It does serve as a basic template that can be expanded as desired. INGREDIENT TYPE DEFINITION EXAMPLES Acidifying agent Provides acidic medium for product stability in liquid Citric acid preparations. Acetic acid Fumaric acid Hydrochloric acid Nitric acid Alkalinizing agent Provides alkaline medium for product stability in Ammonia solution liquid preparations. Ammonium carbonate Diethanolamine Monoethanolamine Potassium hydroxide Sodium bicarbonate Sodium borate Sodium carbonate Sodium hydroxide Trolamine Adsorbent Holds other molecules onto its surface by physical or Powdered cellulose chemical (chemisorption) means. Activated charcoal Aerosol propellant Develops pressure within an aerosol container, which Carbon dioxide expels the ingredients when the valve is opened. Dichlorodifluoromethane Dichlorotetrafluoroethane Trichloromonofluoromethane Air displacement Displaces air in a hermetically sealed container to Nitrogen enhance product stability. Carbon dioxide Antifoaming agent Breaks up and inhibits the formation of foams. Dimethicone Lauric acid NF32 Myristic acid Palmitic acid Simethicone Antifungal preservative Prevents growth of fungi in liquid and semisolid Butylparaben preparations. Use in combination usually enhances Ethylparaben the effectiveness of parabens. Methylparaben Benzoic acid Propylparaben Sodium benzoate Sodium propionate Antimicrobial preservative Prevents growth of microorganisms in liquid and Benzalkonium chloride semisolid preparations. Methylparaben Propylparaben Sorbic acid Antioxidant Prevents deterioration of preparations by oxidation. Ascorbic acid Ascorbyl palmitate Butylated hydroxyanisole Butylated hydroxytoluene Hypophosphorous acid Monothioglycerol Propyl gallate Sodium ascorbate Sodium bisulfite Sodium formaldehyde sulfoxylate Sodium metabisulfite Buffering agent Resists change in pH upon dilution or addition of Potassium metaphosphate acid or alkali. Potassium phosphate, monobasic Sodium acetate Sodium citrate, anhydrous and dihydrate Chelating agent Substance that forms stable water-soluble complexes Edetic acid (chelates) with metals; used in some liquid Edetate disodium pharmaceuticals as stabilizers to complex heavy metals that might promote instability. In such use, they are also called sequestering agents. Clarifying agent Filtering aid used for its adsorbent qualities. Bentonite Talc Colorant Imparts color to liquid and solid (e.g., tablets and FD&C Red No. 3 capsules) preparations. FD&C Red No. 20 FD&C Yellow No. 6 FD&C Blue No. 2 D&C Green No. 5 D&C Orange No. 5 D&C Red No. 8 Caramel Ferric oxide, red Emollient Softens the skin or soothes irritated skin or mucous Acetylated lanolin alcohol membranes. Cetyl acetate Cetyl lactate Cetyl ricinoleate Disopropyl adipate Disopropyl dimerate Glyceryl oleate Hexylene glycol Isopropyl isostearate Isopropyl palmitate Isostearic acid derivatives Maleated soybean oil mixtures Myristyl myristate Octyl dodecanol Octyl hydroxystearate Octyl palmitate Phenyl trimethicone Propylene glycol Tocopheryl acetate Tocopheryl linoleate Triisocetyl citrate Wheat germ glycerides Emulsifying agent Promotes and maintains dispersion of the finely Acacia subdivided particles of liquid in vehicles where it is Agar immiscible. Liquid emulsion or semisolid emulsion Behenoyl Polyoxylglycerides may be the end product. Benzalkonium chloride Benzyl benzoate Caprylic acid Caprylocaproly - Polyoxylglycerides Carbomer Copolymer Carbomer Homopolymer Cetomacrogol Cetyl alcohol Glyceryl monostearate Sorbitan monooleate Polyoxyethylene 50 stearate (myrj23) Encapsulating agent Forms thin shells in which drug is enclosed to ease Gelatin administration. Enteric coating Polymer barrier on tablets meant to prevent Cellulose acetate phthalate medication from breaking down in the stomach, Shellac (35% in alcohol, pharmaceutical glaze) instead allowing breakdown in the small intestine. Film coating Polymer coating applied to tablets meant to protect Hydroxyethyl cellulose the dosage form or modify its release. Hydroxypropyl cellulose Hydroxypropyl methylcellulose (Hypromellose) Methylcellulose (e.g., Methocel) Ethylcellulose (e.g., Ethocel) Flavorant Gives a pleasant flavor and often odor to a Anise oil preparation. Synthetic flavorants may also be used in Cinnamon oil addition to the natural flavorants listed. Cocoa Menthol Orange oil Peppermint oil Vanillin Flavoring/sweetening agent Imparts a pleasant flavor and sweetness to a Acacia syrup preparation. Aromatic syrup Aromatic elixir Cherry syrup Cocoa syrup Orange syrup Syrup Foam adjuvant Improves the stability and reduces the specific Arachidic acid gravity of foam. It may increase the foaming capacity Arachidyl alcohol of surfactants. Behenic acid Behenyl alcohol Cetyl alcohol Hexadecanoic acid Octacosanoic acid Oleyl alcohol Stearic acid Stearyl alcohol Foaming agent Amphiphilic substance that facilitates the formation Brij 38 of foam. Brij 52 Brij 56 Isoceteth-20 Laureth-4 Lecithin Myrj 45 Myrj 49 Myrj 59 Polyglyceryl-4 isostearate Polyoxyethylene (20) sorbitan monostearate (Tween 60) Polyoxyethylene (2) sorbitan monooleate (Tween 80) Sodium lauryl sulfate Sorbitan laurate Sorbitan monolaurate Sorbitan palmitate Triethanolamine lauryl sulfate Gelling agent Increases the viscosity of a substance; can act as a Acrylic acid/ethyl acrylate copolymers stabilizer. Carboxymethyl cellulose Carboxyvinyl polymers Carrageenan gum Egg albumin Gelatin agar Guar gum Hydroxyethyl cellulose Hydroxypropyl guar gum Hydroxyl propylmethyl cellulose Polymethacrylic acid polymers Polyvinyl alcohol Polyvinylpyrrolidone Locust bean gum Quince seed extract Sodium alginate Sodium caseinate Starch Tragacanth gum Xanthan gum Humectant Prevents drying of preparations, particularly Glycerin ointments and creams. Propylene glycol Sorbitol Hydrophilic solvent Liquid with high miscibility with water, used to Azone dissolve solutes. Caprylic acid Diethylene glycol Dimethylacetamide Dimethylformamide Dimethylsulfoxide Dioxolane Di-terpenes Ethylene glycol Glycerin Hexylene glycol Lauric acid Lauryl alcohol Lemonene l-menthol Myristyl alcohol Polyethylene glycols Propylene glycol Terpeneol Terpenes Hydrophobic solvent Liquid with low or no miscibility with water, used to Borage seed oil dissolve solutes. Canola oil Coconut oil Cod-liver oil Corn oil Cottonseed oil Docosahexaenoic acid Eicosapentaenoic acid Evening primrose oils Flaxseed oil Gamma-linoleic acid Linoleic acid Linolenic acid Mineral oil Olive oil Omega-3 and omega-6 fatty acids Salmon oil Sesame oil Some essential oils Soybean oil Sunflower oil Triglyceride oil Wheat germ oil Levigating agent Liquid used as an intervening agent to reduce the Mineral oil particle size of a powder by grinding, usually in a Glycerin mortar. Propylene glycol Ointment base Semisolid vehicle for medicated ointments. Lanolin Hydrophilic ointment Polyethylene glycol ointment Petrolatum Hydrophilic petrolatum White ointment Yellow ointment Rose water ointment pH Modifier (Acidifying Decreases or increases pH in preparations or protects Acetic acid agent/Alkalizing compounds from rapid change in pH. Acetic acid, glacial agent/Buffering agent) Adipic acid Ammonia solution, strong Ammonium carbonate Ammonium chloride Ammonium phosphate Boric acid Calcium carbonate Calcium hydroxide Calcium lactate Calcium phosphate, tribasic Citric acid, monohydrate Citric acid, anhydrous Diethanolamine Fumaric acid Glycine Hydrochloric acid Hydrochloric acid, diluted Alpha-lactalbumin Lactic acid Lysine hydrochloride Maleic acid Methionine Monoethanolamine Monosodium glutamate Nitric acid Phosphoric acid Phosphoric acid, diluted Potassium bicarbonate Potassium citrate Potassium hydroxide Potassium metaphosphate Potassium phosphate, dibasic Potassium phosphate, monobasic Propionic acid Racemethionine Sodium acetate Sodium bicarbonate Sodium borate Sodium carbonate Sodium citrate Sodium hydroxide Sodium lactate solution Sodium phosphate, dibasic Sodium phosphate, monobasic Succinic acid Sulfuric acid Tartaric acid Trolamine Plasticizer Component of film-coating solutions to make film Diethyl phthalate more pliable, enhance spread of coat over tablets, Glycerin beads, and granules. Solvent In preparation of a solution, aqueous or oleaginous Alcohol solvent may be used to dissolve another substance. Bacteriostatic Sodium Chloride Injection Water and hydroalcoholic alcohol, water and glycerin Corn oil may be used as co-solvents when needed. Sterile Cottonseed oil solvents are used in preparations such as injections. Glycerin Isopropyl alcohol Mineral oil Oleic acid Peanut oil Purified water Water for Injection Sterile Water for Injection Sterile