Hollow Fibre Supported Liquid Membrane Extraction of Diphenylhydramine, Chlorpheniramine and Ketoprofen in Pharmaceutical Products

A simple sample pre-treatment method utilizing hollow fibre supported liquid membrane (HFSLM) was carried out on pharmaceuticals samples comprising of cough syrups (CS1 and CS2) and an antiinflammatory product (AI). The active ingredients targeted in the extraction process were diphenylhydramine (DPH), chlorpheniramine (CPA) [(S)-γ-(4-chlorophenyl)-N,N-dimethyl-2-pyridinepropanamine maleate salt] and ketoprofen (KP) [(RS)2-(3-benzoylphenyl)-propionic acid] which were detected by a high performance liquid chromatograph (HPLC-UV/DAD) after HFSLM process. Factors controlling the efficiency of HFSLM extraction such as sample pH, stripping phase pH, enrichment time, stirring speed as well as the organic solvent used for the entrapment of these analytes were optimized to achieve the best selectivity and high enrichment factors. KP extracted from AI product had optimal pH of 10 for the stripping solution and 4 for sample with enrichment factors of 339. DPH had optimal pH of 12 (sample) and 3 for the stripping solution and had enrichment factors of 519. The optimal sample pH for CPA was 0.5 while the stripping phase pH was 13. The HFSLM technique showed 81% recovery of DPH from CS1, while for CPA from CS2 was 78 % and that of KP from AI was 80 %. The LODs obtained were 0.06 μg/L for all the compounds.