Simultaneous Determination of Multiple Preservatives and Antioxidants in Topical Products by Ultra-Pressure Liquid Chromatography with Photo Diode Array Detector

An improved analytical method was developed by ultra-pressure liquid chromatography (UPLC) using design of experiments (DoE) for quantification of preservatives and antioxidants. Benzyl alcohol, benzoic acid, phenoxy ethanol, sorbic acid, methyl paraben, ethyl paraben, propyl paraben, and butyl paraben were selected as preservatives for the study. Similarly, propyl gallate, butylated hydroxy anisole, butylated hydroxy toluene, and ascorbyl palmitate were selected as antioxidants. Cream, gel, ointment, and lotion formulations containing these components were manufactured and quantified using this method. Separation was performed by liquid chromatography (LC) using reverse phase silica base C-18 (2.1mmx100mm, 1.7 mu) column equipped with photo diode array detector. 0.1% v/v ortho-phosphoric acid in water, methanol, and acetonitrile were used for gradient elution. Moreover, extraction and solution stability study of highly oxidizable compound ascorbyl palmitate was performed using a peculiar combination of diluents. The method was found to be simple, precise, accurate, and stability indicating. The applicability of the method was also suggested by evaluating the marketed topical formulations.