Simultaneous estimation of rutin and donepezil through RP-HPLC: implication in pharmaceutical and biological samples.

A HPLC method was developed and validated for the novel combination of rutin (RN) and donepezil (DNP). RN and DNP were simultaneously eluted through a C18 column (Ø 150 × 4.6 mm) with a 60:40 v/v ratio of 0.1% formic acid aqueous solution to methanol at 0.5 ml/min. The purposed method was found linear, selective, reproducible, accurate and precise with percent RSD less than 2. The limit of quantification for RN and DNP was found 3.66 and 3.25 μg/ml, respectively. Validated as per the ICH guidelines, the developed method efficiently quantified RN and DNP co-loaded in DQAsomes (121 nm) estimating matrix effect, release profile, entrapment efficiency, loading efficiency and plasma kinetics.