Assay of orphenadrine citrate in pharmaceuticals via extraction-spectrophotometric method

الملخص EN

An extraction-spectrophotometric technique has been applied and approved for the estimation of orphenadrine citrate in the presence of paracetamol in a binary synthetic mixture and in combined drugs.

The procedure is built on the formation of a soluble red colour orphenadrine citrate – eriochrom black T (EBT) ion pair complex at pH 1.40, while the paractamol not paired.

The produced red colour ion-pair complex was extracted with chloroform and showed maximum absorption at 509 nm.

For quantitative evaluation Beer’s law applied to plot the absorbance against concentration, the relation was a linear in the concentration range of 0.10-6.00 μg/ mL with the molar absorptivity 4.4025 x104 L / mol.

cm.

The limit of detection and limit quantification were 0.024 μg/ mL, and 0.100 μg/ mL respectively.

The intra-assay precision evaluated in terms of % relative standard deviation (RSD) (< 2%).

And accuracy was validated with % recovery (98.8-102.5%).

The results showed that orphenadrine citrate could be determined successfully in the combined tablet without interference by paracetamol and other common co-formulated substance