Survey of microbial quality and product integrity of cosmetics sold in Port Harcourt, Nigeria

Microbial quality of cosmetic products affects their shelf-life and effectiveness. A total of 30 (thirty) unopened cosmetic samples were studied. The methods employed in the analysis included physicochemical characteristics, microbial challenge test while preservative concentrations was determined by high performance liquid chromatography (HPLC). Results showed that less than 10% of the samples contained microorganisms. Pseudomonas aeruginosa was the only isolate recovered from the samples. The preservative capacity of 63.3% of cosmetic samples was ineffective, while 36.7% passed the test. The result of HPLC analysis revealed that values for methyl paraben and propyl paraben ranged from 0.00030 % to 0.134 % and 0.0001% to 0.153% respectively. The values for physiochemical parameters analysed varied between 4727 mPa.S and 19,820 mPa.S for viscosity; and from 2.4 to 5.85 for pH. Moisture contents were between 14.59 % and 22.6 %. Our findings indicate that majority of the cosmetic samples do not contain microorganisms while a few samples were adequately preserved. The challenge test showed that preservatives were active more on the inoculated Candida albicans than on bacterial species (Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922) and Staphylococcus aureus). This will help in monitoring and reducing deterioration of cosmetic products, while maintaining quality.