T. Nawas et A. Alkofahi, MICROBIAL-CONTAMINATION AND PRESERVATIVE EFFICACY OF TOPICAL CREAMS, Journal of clinical pharmacy and therapeutics, 19(1), 1994, pp. 41-46
Nineteen different brands of topical creams were tested in duplicate f
or microbial growth. The efficacy of their preservation was assessed,
when possible, by standard pharmacopoeial procedures. Microbial growth
was demonstrated in cultures from all specimens. However, high counts
(> 10(4) c.f.u./g) were obtained from eight specimens from six differ
ent brands. The microbes were found to belong to different species of
bacteria and fungi including Pseudomonas aeruginosa. Two samples of ea
ch of the seven, easily emulsifiable creams, were challenged with stan
dard strains of Staphylococcus aureus, Escherichia coli, Pseudomonas a
eruginosa and Candida albicans to assess the efficacy of the preservat
ives used in their preparations. With the exception of a single brand,
all creams tested were ineffectively preserved. This study highlights
the dangers of marketing domestically prepared topical creams and mor
e effective monitoring of the components for all topical creams is rec
ommended. The inclusion of a proper preservative system in these formu
las is essential.