Estimation of psoralen from herbal formulations containing Psoralea corylifolia using the RP‑HPLC‑DAD method and its application to a pharmacokinetic study

Abstract

Background: Psoralea corylifolia L. (Fabaceae, seeds) is used in many formulations for the treatment of a wide range of ailments. Aims and Objective: To develop a reverse phase high‑performance liquid chromatography‑photodiode array detector (RP‑HPLC‑DAD) method for quantitation of psoralen from P. corylifolia and its related formulations. Materials and Methods: Separation and detection of psoralen from various herbal formulations was achieved on reversed phase Cosmosil C18 column using acetonitrile: Distilled water (40: 60, v/v; flow rate – 1.0 mL/minute) and the PDA detector (247 nm). The method was validated as per the norms of the International Conference on Harmonisation (ICH) guidelines and applied to study the pharmacokinetics of an oil‑based Ayurvedic preparation, in terms of bioavailable psoralen. Results: The HPLC method showed a linear detector response from 20.0 to 5000.0 ng/mL (r2=0.9998) for psoralen. The content of psoralen in P. corylifolia and its marketed formulations was determined, which showed remarkable variations as per the nature and complexity of the formulation. The absorption and elimination profile of psoralen, from an oil‑based Ayurvedic preparation, was developed on its topical application in rabbits. Psoralen was detected in the plasma 0.25 hours post application of Bakuchi Taila with 0.46% bioavailability. Conclusion: The method was found to be sensitive, accurate and reproducible. Therefore, it can be recommended for marker‑based standardisation and quality assurance of P. corylifolia and its formulations. It can also be applied to study the pharmacokinetic profile of the traditional preparations of P. corylifolia. Key words: Formulations, Psoralea corylifolia, psoralen, pharmacokinetics, RP‑HPLC‑DAD