Spectrophotometric determination of raloxifene in pure form and pharmaceutical formulation

ABSTRACT

Five simple and selective spectrophometric methods were developed for quantitative determination of raloxifene [RAL] in pure forms as well as in its pharmaceutical formulation. Method [A] is based on the nitration and subsequent complexation with a neuleophilic reagent forming a yellow colour with [lambda][max] at 389 nm, Beer's law was obeyed in the concentration range 1.5-9 micro g ml[-1]. LOD and LOQ were found to be 0,054 and 0.180 micro g ml[-1] respectively. Method [B] is based on the coupling of the drug as a phenolic compound with the diazonium salt of o-nitroaniline forming red azodye with [lambda][max] at 520nm. Good linearity obtained in the range of 6-48 micro g ml[-1]. LOD and LOQ were found to be 0.711 and 2.372, respectively. Method [C] is based on coupling with diazo reagent [method B] and subsequent chelation with copper sulphate and extraction of the resulting chelate into chrorofom and measuring the chloroformic layer at 388 nm. Beer's law was obeyed in the concentration range 6-42 micro g ml[-1]. LOD and LOQ were found to be 0.268 and 0.894 micro g ml[-1], respectively. Method [D] involves the reduction of follin ciocalteu's phenol reagent [FCP] by the drug to give a blue colored product which exhibites an absorption maximum at [lambda][max] 660 nm. Regression analysis of Beer's plot showed good correlation in the concentration rage of 1-8 micro g ml[-1]. LOD and LOQ were found to be 0.043 and 0.145 micro g ml[-1], respectively. Method [E] involves the determination of [RAL] by difference spectrometry, the absorbance of the acidic drug solutions were measured against the alkaline drug solutions at 240 nm and calibration graph was plotted which is rectilinear in the range of 1-8 micro g ml[-1]. LOD and LOQ were found to be 0.032 and 0.134 micro g ml[-1], respectively. The optimization of the reaction conditions is investigated, the methods were successfully applied to the analysis of RAL in its pharmaceutical formulation with good recovery