Derivative Synchronous Fluorescence Spectroscopy for the Simultaneous Determination of Dapoxetine Hydrochloride and Vardenafil in Binary Mixtures

Abstract

535.372:615.45 The fi rst and second derivative synchronous fl uorescence spectroscopy (FDSFS&SDSFS) methods have been developed and validated for the simultaneous analysis of a binary mixture of dapoxetine hydrochloride and vardenafi l. Method 1A describes a measurement of the normal synchronous fl uorescence intensity of these drugs at ®�� = 35 nm using sodium dodecyl sulfate as the fl uorescence enhancer in aqueous solutions. This method was extended (Method 1B) to the use of FDSFS&SDSFS for the determination of both drugs. The fl uorescence concentration plots were linear over the range of 1–10 and 0.2–2 o g/ml for dapoxetine hydrochloride and vardenafi l, respectively, with lower detection limits of 290 and 62.5 ng/ml, and quantifi cation limits of 890 and 190 ng/ml for dapoxetine hydrochloride and vardenafi l, respectively. The proposed method was applied for the simultaneous determination of DAP and VAR in different synthetic mixtures and in co-formulated pharmaceutical preparation. The results obtained were in good agreement with those obtained using a reference method.