Evidence of sildenafil citrate in aphrodisiac herbal formulations marketed in San Salvador El Salvador, by HPLC-DAD and NMR 1H methodology

Abstract

Introduction: Herbal products have been used for the treatment of many diseases and unlike conventional drugs, they are perceived as safe and harmless due to their natural origin. The adulteration of natural products used for the improvement of sexual desire is becoming recurrent nowadays. Objective: This study detects the presence and determines the pharmacological dose of sildenafil citrate, a phosphodiesterase-5 inhibitor, in presumed adulterated natural products, that are commercialized in markets and “sex-shops” type store as stimulants of sexual desire in men. Methodology: The sildenafil content in 21 herbal products was identified and determined, using chromatographic and spectroscopic techniques (CCF, HPLC-DAD, and NMR 1H). Results: There was no evidence of the presence of sildenafil in the evaluated products from the markets. However, in the sex-shop type sales, with high probabilities of acquisition of adulterated products with this active principle, concentrations found were in a range from 12.7-132.2 mg/capsule. Representing lower, intermedium and higher doses than those recommended by the FDA. Conclusion: For consumers of fraudulent herbal products, there may be an interaction of sildenafil with vasodilator medicines such as nitrates, used for angina pectoris, and congestive heart failure. These interactions, together with the adverse cardiac-type (hypotensive) effects of sildenafil, could have serious effect on the health of consumers. Strict regulation of the natural products industry in sampled sites is urged.