Quality control testing of various samples of peppermint oil collected from local market of Karachi

ABSTRACT

Menthol is the most commonly used substance in many cosmetics and pharmaceutical products either as an active ingredient or in the form of excipient. In the present study, different samples of commercially available peppermint oil were subjected to standardization by determination of physicochemical characteristics, acid value, and resinified oil content. Thin layer chromatography [TLC] has been used to confirm the presence of menthol. The result showed that the quality control test performed for the evaluation of the physicochemical parameters of peppermint oil can be considered useful in its standardization. The results of acid value and the resinified oil tests, carried out on the raw material, have found to be within the standard limits. The results indicated specified number of free fatty acids and absence of greasy impurities. The data obtained from the study would be useful in the authentication of the commercial peppermint oil samples. In TLC studies, the Rf value of the active constituent has been determined by comparison with its standard spot. This technique may be used as a tool for the correct identification of the active constituent which could help in the standardization of the peppermint oil samples