ABSTRACT:
For the identification and characterization of main impurities in Epalrestat, a responsive and rapid analysis of LC-MS/MS and NMR was created. Epalrestat is used in diabetic neuropathy therapy, which in patients with diabetes mellitus is one of the most severe long-term complications. Epalrestat is a derivative of carboxylic acid and a non-competitive and reversible inhibitor of the reductase of the aldose. It reduces intercellular sorbitol deposition that is thought to be causing diabetic neuropathy, retinopathy, and nephropathy. Aldose reductase is the key enzyme in the polyol pathway, the enhanced activity of which is the basis for diabetic neuropathy this enzyme is targeted by the aldose reductase inhibitors (ARI). Epalrestat is the only commercially available API. It is easily absorbed in the neutral tissues and has minimal side effects inhibiting the enzyme. At 5.1 RT in Epalrestat, one of the primary impurities was observed in the analytical HPLC process. Preparative HPLC technique was used to further characterize the impurity. To predict the structure, isolated impurity was subjected to amass and NMR analysis of LC-MS/MS was performed using a reverse-phase column of C18 and with a mobile step consisting of methanol and ammonium type in a ratio of 70:30 to pH 4.6. The injection volume is 10 µL, and the binary gradient system was used to isolate. The flux rate was maintained at 1.0 ml/min. The temperature of the column was held at 45oC. For this study, the MS conditions were adopted with a scan range of m/z= 50 to 500 with a dwell time of 3 seconds.