Adulteration of Herbal Preparations with Sildenafil and Tadalafil

Abstract

Herbal preparations for sexual dysfunction have increasingly been used by Sudanese patients over the last 10 years as they are readily available and perceived to be safe. Recently, repeated complaints about side effects, similar to those of sildenafil and tadalafil, have been disclosed by some patients who were on such herbal preparations. Based on this, we suggest that such herbal preparations are adulterated by sildenafil and tadalafil. Objective The aim of this study was to examine the presence/absence and quantity of sildenafil and tadalafil drugs in these herbal preparations. Methodology Thirty samples, collected form open market and/or licensed companies, were screened for Sildenafil and Tadalafil using TLC and adapted HPLC as qualitative and quantitative methods, respectively. Results: TLC analysis revealed that 40% of the tested samples were found to be adulterated with sildenafil and tadalafil (3:1). HPLC analysis revealed that a single dose of the adulterated samples contained 165.46±0.79 mg of sildenafil or 60.76±0.60 mg of tadalafil. Conclusion: Detection of sildenafil (>165 mg) and tadalafil (>60 mg) in 40% of the tested samples could explain the side effects reported by patients using these herbal preparations. Knowing that the maximum daily dose is 100 mg for sildenafil and 20 mg for tadalafil, repeated use of these preparations could result in potentially fatal side effects