Development and Substantiation of a RP-HPLC Method for Monitoring of Impurities in Pirfenidone Drug Substance

Abstract

A simple, rapid and rugged RP-HPLC method was developed for evaluation and quantification of impurities present in Pirfenidone (PFD) drug substance. Impurities were separated and determined on a Zorbax RX-C18 column (250 mm length, 4.6 mm inner diameter and 5.0 μm particle size, octadecylsilane chemically bonded to porous silica) with 0.02 M KH 2 PO 4 buffer and acetonitrile as mobile phase using a simple gradientelution program. The column flow rate of 1.0 mL per minute was used for the separation. The detection wave length was fixed at 220 nm. The method was substantiated with respect to specificity, precision, linearity, range, accuracy, ruggedness, limit of detection and quantitation. The impurities were identified as 2-hydroxy-5-methylpyridine and Iodobenzene. The linearity range obtained was 0.017 to 0.380 μg/mL for 2-hydroxy-5-methylpyridine, 0.047 to 0.382 μg/mL for Pirfenidone and 0.030 to 0.99 μg/mL for Iodobenzene with the retention times of 3.248 min, 10.608 min and 24.241 min for 2-hydroxy-5-methylpyridine, Pirfenidone and Iodobenzene, respectively. The percentage recoveries of 2-hydroxy-5-methylpyridine and Iodobenzene were in the range of 94.08% - 104.12%. The LOD and LOQ values were found 0.000005 mg/mL, 0.000017 mg/mL for 2-hydroxy-5-methylpyridine and 0.009 μg/mL, 0.030 μg/mL for Iodobenzene, respectively. The method is found to be suitable for the quantitation of impurities along with Pirfenidone drug substance. The method was validated as per the International Conference on Harmonization (ICH) guidelines.