Comparative standardization study for determination of reserpine in Rauwolfia serpentina homoeopathic mother tinctures manufactured by different pharmaceutical industries using HPTLC as a check for quality control

Background: Rauwolfia serpentina (L.) Benth. ex Kurz (Apocynaceae) (Indian snakeroot), popularly known as Sarpagandha (Sanskrit), is used for the treatment of insanity, fever, snake bites, anxiety and in neuropsychiatric conditions. The antihypertensive actions of Reserpine are a result of its ability to deplete catecholamines (amongst other monoamine neurotransmitters) from peripheral sympathetic nerve endings which are normally involved in controlling heart rate, force of cardiac contraction and peripheral vascular resistance. Objective: Comparative study of Reserpine content in R. serpentina homoeopathic mother tinctures manufactured by different pharmaceutical industries and in-house mother tinctures applying high-performance thin-layer chromatography investigative techniques to facilitate the use of correct species. Materials and Methods: The authentic samples of roots of R. serpentina were supplied by Centre of Medicinal Plants Research in Homoeopathy, Emerald, Tamil Nadu, India. Authentic plant material was used to prepare the mother tincture (as per Homoeopathic Pharmacopoeia of India). Reserpine (C33H40N2O9,M.P. 360°C, purity >99% w/w by high-performance liquid chromatography [HPLC]) was purchased from Sigma-Aldrich as a standard reference. The solvents for the study, namely, ethanol, HPLC water, toluene, ethyl acetate, diethylamine and chloroform were of analytical grade purity (MERCK Ltd.,), used throughout. Results: Five samples of mother tinctures were used for the study, in-house mother tinctures (labelled: D and E) of R. serpentina shows a higher amount of Reserpine content than the marketed samples (labelled: A, B and C). Conclusion: It may be concluded that mother tinctures prepared by authentic plants showed the excess amount of Reserpine rather than that of mother tinctures procured from the market.