Types of Preservatives in Pharmaceutical Chemistry

Preservatives are used in pharmaceutical chemistry to prevent the growth of bacteria, mold and other microbes. They are used in the manufacture of pharmaceutical drugs and cosmetics, for their individual antibacterial (destroying and inhibiting the growth of bacteria) and antifungal (destroying and inhibiting the growth of fungus) properties.

Benzoic Acid

Benzoic acid (C7H6O2) is used as a pharmaceutical preservative for its antifungal properties. It is produced commercially by oxidizing toluene. According to "Appl Environ Microbiol", benzoic acid and its salts inhibit the growth of bacteria, yeast and mold. It is used in chemically based ointments to treat fungal diseases, such as athlete's foot, ringworm and tinea. A 0.1 percent concentration of benzoic acid is used in pharmaceutical applications. It is used as an antiseptic in mouthwashes and lotions.

Salicylic Acid

Salicylic acid (C7H6O3) is found as a fluffy powder or as white crystals. It is used as a preservative in food for its antimicrobial properties. Salicylic acid is toxic in large quantities.

Cresol

Cresol, or cresylic acid, (C7H8O) is used as a preservative in pharmaceutical chemistry. It inhibits the growth of numerous pathogenic organisms and is a powerful germicide and antiseptic. Cresol is derived from coal and popularly used to make wood preservatives. It is used for its antioxidant properties to form dyes and fragrances. 0.3 percent concentration of cresol is used in pharmaceutical chemistry. According to the Minnesota Pollution Control Agency, short-term exposure to the substance causes throat irritation, nasal constriction and other respiratory tract irritation. P-cresol, m-cresol and o-cresol are possible human carcinogens (cancer causing substances).

Cetrimide

Cetrimide (C19H42N+) is a popular antiseptic agent that exists as a white crystalline powder. It is a popular preservative for its antimicrobial properties. Cetrimide affects and disrupts the cellular functions of microorganisms, rendering them ineffective. It is used in pharmaceutical chemistry as an antistatic agent, detergent sanitizer, softener for paper products and textiles, algaecide, emulsifying agent, pigment dispersant and an active ingredient used in conditioners. A dilute solution of cetrimide is effective in treating sore gums.

Ethyl Paraben

Ethyl paraben (HO-C6H4-CO-O-CH2CH3), or ethyl para-hydroxybenzoate, is a an antimicrobial preservative most commonly used in cosmetics and pharmaceutical formulations. It is an antifungal agent and found as a white crystalline powder. Ethyl paraben is used as a stand-alone agent or in combination with other antimicrobials and parabens. It is ineffective against molds and yeasts.