Spectrophotometric method for pregabalin determination: An experimental design approach for method development

A simple, sensitive and reproducible spectrophotometric method is developed for determining the pregabalin (PGB) content in bulk and in capsule dosage form using an experimental design approach. The proposed method is based on the condensation reaction of PGB (primary amine) with p-dimethylaminobenzaldehyde (PDAB) in an acidic medium to form a PGB-PDAB complex. The PGB-PDAB complex shows maximum absorption at 395.80 nm. The proposed method is validated according to the ICH Q2 (R1) guidelines for validation of analytical methods. The percentage purity of PGB in capsule dosage form as determined using the proposed method is 100.05 ± 1.48 whereas the corresponding value by the official method (Indian Pharmacopoeia, 2010) is 100.46 ± 0.41. The t-value and F-value are calculated for statistical comparison and are found to be 0.60 and 0.08, respectively. The proposed method may recommend for routine quality control analysis of PGB in its pharmaceutical dosage form.