Spectrophotometric Determination of Diphenhydramine hydrochloride and Application to Pharmaceutical Preparations


The research involves the use of analytical method for determination of the diphenhydramine hydrochloride (DPH) drug in some pharmaceutical preparations using molecular absorption technique (UV-Vis.) in addition to the investigating of complexes obtained. The optimum analytical data obtained throughout of study could be summarized as follows: order of addition (DPH + 2% CS2 in CHCl3+Ag(I), pH(11),volume of ammonia solution (1ml), concentration of Ag(I) (8µg/ml), aqueous : organic phase ratio 1:1, reaction time (4 minutes), extraction time (8minutes), reaction temperature 25oC, one extraction process, extraction ratio (E%=99.82) chloroform proved to be the best solvent for extraction of DPH-Ag complex without interferences, λmax.=363nm. The analytical figures obtained were: linear dynamic range (0.25-80µg/ml)for DPH , RSD% (0.396), D.L (0.29µg/ml), Erel% (0.125), recovery (99.87%).This method was applied for determination of DPH in pharmaceutical preparation (syrup) using direct and standard addition methods, recovery's was found to be (97.8%, 98.2 %).