Development and application of a validated HPLC method for the analysis of dissolution samples of gabapentin drug products

A simple isocratic reversed-phase HPLC method was developed and validated for the analysis of dissolution samples of gabapentin tablets and capsules. Separation of gabapentin from its major degradation impurity, 3,3-pentamethylene-4-butyrolactam was achieved on a Phenomenex Luna Cyano column using a methanol–acetonitrile–20 mM KH2PO4 (pH 2.2) (5:5:90, v/v/v) mobile phase. The compounds were eluted isocratically at a flow rate of 1.25 mL/min. Both compounds were analyzed with UV detection at 210 nm. The method was validated according to USP Category I requirements for gabapentin. The validation characteristics included accuracy, precision, linearity, range, specificity and limit of quantitation. Robustness testing was also conducted to evaluate the effect of minor changes to the chromatographic system and to establish appropriate system suitability parameters. Validation acceptance criteria were met in all cases. This method was used successfully for the quality assessment of five gabapentin drug products.