Validation and eco-scale assessment of stability-indicating HPTLC method for quantitative analysis of carbamazepine and its degradation product, iminostilbene, in pure forms, pharmaceutical preparations, and spiked human plasma

Abstract

Paying attention to issue of environmental protection is an unavoidable duty which encourages analytical society to balance between establishment of new analytical method and preservation of the environment from the harmful chemicals. By adopting this concept, an excellent green high-performance thin-layer chromatography (HPTLC) method was developed for assessment of carbamazepine, the antiepileptic drug, and iminostilbene, the main degradation product and its official impurity. Separation of the structurally related components was completed on HPTLC sheets using a mixture of petroleum ether: acetone (7:3, v/v) as a developing system with UV detection at 230 nm. To assess the greenness profile of the developed method compared with the official high-performance liquid chromatography (HPLC) method, analytical semi-quantitative eco-scale assessment protocol was applied. The suggested method was confirmed to be greener than the official method with regard to solvent consumption and waste emission. The suggested method was successfully applied to determine carbamazepine in the marketed dosage forms with no intrusion of other co-formulated ingredients. Successful application of the developed method was also proved via simultaneous analysis of carbamazepine and iminostilbene in raw materials and human plasma samples in ranges of 0.1–1.4 μg/band and 0.1–1.2 μg/band for carbamazepine and iminostilbene, respectively. As the maximum plasma concentration of the studied medication was within its calibration range, the proposed HPTLC method can be employed for further pharmacokinetic studies. For comprehensive validation of the presented method, ICH figures of merit were evaluated.