A Simultaneous Quantification of Four Potential Genotoxic Impurities Purinediol Hydrochloride, N7-Isomer, Monoalkyl Contaminant and Diacetyl Purine Present in Penciclovir Using LC-MS/MS

Background: Penciclovir is a medication for antiviral therapy for curing different kinds of herpes virus infections. The four contaminants are the starting materials of Penciclovir which are present at a trace level in the drug in which one of its impurities is its isomer. Purinediol Hydrochloride, N7-Isomer, Monoalkyl contaminant and Diacetyl Purine are the four potential impurities present in the drug. Materials and Methods: The separation was achieved in the Zorbax SB C8 column using a gradient elution of 10 mM Ammonium bicarbonate in water as a buffer and a mixture of Methanol and Acetonitrile in the ratio of 20:80 v/v at a flow rate of 0.6 mL/min at 40°C. The Agilent Q-TOF 6540 series instrument was used in positive polarity in the scan range of 50-100 m/z. The sensitive and rapid Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) technique was developed for the quantification of four impurities present in the drug. Results: Various validation parameters have been studied. The correlation coefficients of impurities and their linearity values are quite satisfactory within the examined range. The proposed method was sensitive in the linearity range from 0.6 ppm to 12.0 ppm. Conclusion: This method can be used to identify the impurities in Penciclovir drug substances during manufacturing.