Abstract

ANTIMICROBIAL EFFICACY OF LOW LEVEL COSMETIC PRESERVATIVES

Ch. Lalitha*and P. V. V. Prasada Rao

ABSTRACT

Preservatives are used in cosmetics to inhibit the development of microorganisms either previously existing or introduced during the use. An ideal preservative could be one that controls the microbial growth effectively at optimum concentration, while many preservatives cause allergic contact dermatitis and also show other side effects when employed on a sensitive human body. Since no single preservative could control the proliferation of microorganisms at lower concentrations for long period, use of a mixture of preservatives can potentially have synergistic effects against microorganisms. One more advantage of using a combination of preservatives is that, they can address a wide spectrum of microorganisms. In the present study the antimicrobial efficacy of the preservatives Phenoxyethanol (PE), Potassiumsorbate (PS), Sorbicacid (SA), Methylparaben (MP), Propyl paraben (PP) and Sodiumbenzoate (SB) were investigated. The Minimum Inhibitory Concentrations (MIC) of the preservatives singly and in combinations against Micrococcus luteus, Staphylococcus epidermidis, and Pseudomonas aeruginosa were studied. A series of challenge tests was used to explore Antimicrobial efficacy of preservatives in certain cosmetic products to verify the effectiveness of different combinations of preservatives.

Keywords: preservative, allergic, low level concentrations, wide spectrum, challenge tests.