Title 7. PRESERVATIVES.pdf ✅

PHARMD GURU Page 1 INTRODUCTION:  Preservatives are added to various pharmaceutical dosage forms, cosmetic preparations and food preparation to prevent microbial contamination.  In ophthalmic and parenteral formulations, preservatives are used to maintain sterility in the event of accidental contamination during use. AN IDEAL PRESERVATIVE:  Must effective at low concentrations against all possible microorganisms.  Should be nontoxic and compatible with other constituents of the preparation.  Should be stable for the shelf life of the preparation. CLASSIFICATION: 1) P-Hydroxybenzoic Acid Derivatives: Methylparaben, Propylparaben, Butylparaben, Ethylparaben 2) Ester Derivatives: Sodium Benzoate, Sodium Propionate, Potassium Sorbate 3) Alcohol Derivatives: Chlorobutanol, Benzyl Alcohol, Phenylethyl Alcohol 4) Acid Derivatives: Benzoic Acid, Sorbic Acid 5) Mercurial compounds: Phenylmercuric Nitrate, Phenylmercuric Acetate 1)P-HYDROXYBENZOIC ACID DERIVATIVES: Esters of p-hydroxybenzoic acid is known as parabens. PRESERVATIVES


PHARMD GURU Page 4  Chlorobutanol (trichloro-2-methyl-2-propanol) is a preservative.  It has antibacterial and antifungal properties. SYNTHESIS OF CHLOROBUTANOL: BENZYL ALCOHOL:  Benzyl alcohol is used as a preservative in vials of injectable drugs in concentrations of 1% to 4% in water or saline solution.  Benzyl alcohol has the added merits of having a local anesthetic action. PHENYLETHYL ALCOHOL:  Phenyl-ethyl Alcohol occurs naturally in rose oil and pine needle oil.  It is used primarily in perfumery.