Microbiological Quality and in Use Preservative Capacity of Shampoo Preparations Manufactured in Jordan

The microbiological quality of 16 different shampoo formulations (manufactured by 16 different factories) and marketed in Jordan was investigated to determine the preservative capacity of these products at the time of sale and after use. Procedures used were according to those described in ISO technical standards. Thirteen (81.25 %) of the formulations studied were found to be free of contamination. One product harbored Escherichia coli and 2 contained Pseudomonas aeruginosa. Total microbial count in the contaminated brands was 105 CFU / ml. When the contamination free products were returned after a period of normal use, 7 (53.85 %) harbored variety of gram negative and positive bacteria; high numbers of bacteria were detected in 5 (38.5 %) of the returned products. Cocamide diethanolamide in mineral salts medium supported the growth of P. aeruginosa ATCC 9027, whereas sodium lauryl ether sulphate was not inhibitory at the concentration usually used in shampoo formulations. It is concluded that unless adequately preserved, shampoo ingredients can support the growth of microorganisms known to cause spoilage and / or possible health problems. Manufacturers of shampoos in Jordan need to improve the in use preservation efficacy of their products before gaining the confidence of consumers.