1. API: Any substance or mixture of substances intended to be used in the manufacture of a drug (medicinal) product and that, when used in the production of a drug, becomes an active ingredient of the drug product. An active pharmaceutical ingredient is any part of a drug that produces any effect.
2. Preservatives: Preservatives are added to stop microbial growth. Preservatives for ointment include p-hydroxy benzoates, phenol, benzoic acid, sorbic acid, methyl paraben, propyl paraben, quaternary ammonium compounds, mercury compounds, etc. The preservatives should not react with any of the formulation's components. Plastic containers may absorb the
preservative, decreasing the concentration of the preservative for
killing the bacteria.
3. Humectants: Glycerin, propylene glycol, and sorbitol may be added to prevent the preparation from losing moisture.
4. Emulsifying agents: If required, Polysorbate and anionic emulsifying agents are added.
5. Antioxidant: Some ingredients like wool fat and
wool alcohols are susceptible to oxidation. Therefore, a suitable antioxidant
may be incorporated to protect the active ingredients from oxidation.
6. Organoleptic agents: suitable coloring agents –
(amaranth, brilliant blue, etc.) and flavoring agents (vanilla, strawberry,
raspberry) are added. Ointment must be
stored at an optimum temperature otherwise separation of phases may take place
in the emulsified products which may be very difficult to remix to get a
uniform product.