Evaluating preservative efficacy in pharmaceutical and cosmetic products

In 1965 the Royal Swedish Medical Board reported high levels of microbial contamination in nan-sterile drug products not normally required to be sterile (Kallings and Enerfeldt, 1965], Since then a number of surveys have confirmed these findings in both pharmaceutical and cosmetic products e.g. Schiller et.al. ( 1968], Anon (1971 a],Bowman, White and Lyles ( 1971), Westwood (1971), Kruger (1973).

Microbial contamination of such products is undesirable because it can cause spoilage of the preparation and pose a health hazard to the user ( Bruch, 1972). Various regulatory bodies have imposed or advised limits on the types and/or numbers of organisms that are undesirable (Engel, 1967) Bruch 1971, 1972; Anon 1972, 1975b). Methods to monitor contamination have been published (Allwood, 1971; Kruger, 1973; British Pharmacopoeia, 1973; Anon, 1975b, 1976, United States Pharmacopoeia, XIX revision, 1975) and guides to good manufacturing practices produced (Anon, 1975a, 1975b).