Development of HPLC method coupled with fluorescence detection for simultaneous determination of donepezil HCl and trazodone HCl in spiked human plasma and tablets dosage forms

Abstract

Elderly people with dementia are commonly suffered from sleep disorders. So, the use of Donepezil hydrochloride as anti-Alzheimer drug and Trazodone hydrochloride as antidepressants with hypnotic action is very important in these cases. This study reports about novel and sensitive RP-HPLC method with fluorescence detection for simultaneous bioanalytical determination of Donepezil hydrochloride (DON) and co-administered, Trazodone hydrochloride (TRA) in their pure forms, spiked human plasma and tablets. Elution of both drugs was achieved with excellent resolution using a RP-C18 Hypersil Gold column and an isocratic mobile phase consisting of phosphate buffer (50mm, pH 4.6): methanol: acetonitrile (60:35:5) with a flow rate of 1.5mL/min and 20μL as injection volume. A Fluorescence detector at 300nm for excitation and 400nm for emission was used. Retention times were 4.3 and 6.3min for Donepezil hydrochloride and Trazodone hydrochloride, respectively. Linearity ranges of the assay were 25-1000 and 50-5000ng/mL and the limits of detection (LOD) and quantitation (LOQ) were 8.52, 15.47 and 25.81, 46.89ng/mL for Donepezil hydrochloride and Trazodone hydrochloride, respectively. The high sensitivity of the proposed method enabled the successful determination of the cited drugs in spiked human plasma with mean percentage of recoveries of 91.58±3.34 and 100.30±5.11 for Donepezil hydrochloride and Trazodone hydrochloride, respectively.