Simultaneous determination of chloropheniramine maleate and dextromethorphan hydrobromide in plasma sample by hollow fiber liquid phase microextraction and high performance liquid chromatography with the aid of chemometrics.

A simple and high sensitive technique based on three phase hollow fiber liquid phase microextraction (HF-LPME), optimized by using a four-variable experimental design and response surface methodology was performed to evaluate dextromethorphan hydrobromide (DEX) and chloropheniramine maleate (CLP) simultaneously in human plasma. The influence of source phase pH, HCl concentration of acceptor phase, time and salt addition were investigated. Under the optimized conditions analytes were extracted in their neutral form, pH 12.5 and salt concentration 2% (w/v), through a supported liquid membrane (SLM) of hexadecane into the HCl 0.0005 mol L(-1) located inside the lumen of hollow fiber to be back extracted. The mass transfer of the analytes from the donor phase through the SLM into acceptor phase was driven by the pH gradient. Determination was accomplished by UV-high performance liquid chromatography with recoveries 92% and 84% for CLP and DEX, respectively. Linearity was obtained in the range of 0.01-1000 μg L(-1) (R(2)>0.994). The obtained enrichment factors (EFs) were 233-276 for DEX and CLP respectively and limits of detection were 0.003 μg L(-1) with RSDs below 6%. The method proposed acceptable values to determine CLP and DEX in plasma samples sensitively and accurately.