Development of multiple time point stability indicating assay method and validation of nabumetone by RP-HPLC

Nabumetone is a Non-steroidal anti-inflammatory drug (NSAID) which belongs to a drug class which provide antipyretic and analgesic effects in lower doses and anti-inflammatory effects in higher doses. A simple, highly sensitive, accurate and isocratic RP-HPLC stability-indicating method was developed and validated for determination nabumetone by using Cosmosil C₁₈(150x4.6mm, 5μm) column using Acetonitrile: water pH-5 (55:45 %v/v) as mobile phase at a flow rate of 0.8ml/min. The detection was done by using PDA(Photo diode array) detector at 229nm. Calibration curves for all drugs were in the range of 0.125-8 μg/ml and the linear regression coefficients were more than 0.999. Recovery rate was in the range 98.8% to 100.5%. The limits of detection was found to be 0.035μg/ ml. Also, the limits of quantification was 0.107 μg/ml. Repeatability and Intermediate precision was done and the % RSD was found to be less than 1%, by changing few method parameters robustness was evaluated which has shown %RSD of less than 2%. Study aimed to conduct forced degradation studies and develop a simple, effective method which can effectively separate drug from its degradation products. This study was conducted at multiple time points to estimate the rate of degradation. Stress testing was done for acidic degradation, basic degradation, neutral hydrolytic degradation, oxidative degradation, dry heat degradation and Photo stability study. The order of stability for Nabumetone was found to be H₂O₂ <acid < alkali < wet heat<photolysis <dry heat. This developed method was applied on tablet formulation to calculate % assay and it was found to be 101.9%.