This paper describes the validation of an isocratic HPLC method for the assay of Gabapentin Capsule and the evaluation of the stability of drug substance after stress test by Photodiode array detection. the HPLC separation was achieved on a Beckman ultra sphere C18, 4.6 mm ´ 25 cm is suitable using mobile phase water: acetonitrile: Methanol: phosphate buffer solution (55:35:10:0.1) was used . The flow rate was 1ml/min and detection was set at 210 nm. Chromatograph of the standard solution, and record the peak responses as directed under procedure: the column efficiency is not less than 6000 theoretical plates, the tailing factor Gabapentin is not more than 2.0, and the relative standard deviation for replicate injections is not more than 1.0%. Chromatograph the resolution solution, and record the peak responses as directed under procedure: the resolution, R, between Gabapentin and Gabapentin related compound A is not less than 1.5.
