Validation of quantitative procedure for determination methylparaben and propylparaben in ointment by high performance liquid chromatography

Abstract

       The preservatives methylparaben and propylparaben are mainly used in pharmaceutical and cosmetic products. However, monitoring of these preservatives is essential as they need to be used with the allowable concentration to ensure the safety of consumers. The aim of study is to develop an analytical method for the simultaneous quantitative determination of methylparaben and propylparaben in ointments by high performance liquid chromatography. The samples are dissolved by ethanol:H2O (70:30, v/v) and quantifies by high – performance liquid chromatography, using stainless steel RP–18 column (250 mm x 4.6 mm i.d., 5 μm particle size), with a mobile phase containing methanol:kali dihydrophosphat (65:35, v/v) and PDA detector at 256 nm. This method meets requirements for specificity, system compatibility, precision, linearity and accuracy according to the ICH guideline. The extraction and measurement method could be applicable for oinments containing methylparaben and propylparaben.