Use of rose bengal in the colorimetric determination of some anti histamines

A precise colorimetric method is described for the estimation of phenyltoloxamine citrate, diphenyltoloxamine hydrochloride and chlorpheniramine maleate. The method depends on ion-pair extraction of association formed between tertiary amines and Rose Bengal [RB]. The reddish-purple ion associated formations were readily extractable in dichloromethane and exhibited maximum at 555 nm. The method obeys Beer's law in the concentration range 2-20 mug ml-1 for diphenylhydramine hydrochloride or chlorpheniramine maleate and 4-40 mug ml-1 for phenyltoloxamine citrate. Optimization of the experimental conditions is described. The proposed method was applied to the analysis of these drugs in pharmaceutical preparations, and results were in good agreement with those obtained by the BP or USP method

Extraction-spectrophotometric determination of prazosin hydrochloride with palladium [II]

The described spectrophotometric determination of prazosin hydrochloride [PZH] involves the extraction of the PZH-Pb [II] complex from an acetate buffer solution pH 6.0 into a chloroform layer. The absorbance of the extracted solution is measured at 420 nm. The molar absorptivity of the complex is 2.1 x 103 l mol-1 cm-1 at 420 nm. The effects of pH [4-10], Pb [II] chloride concentration and shaking time were studied. The ratio of prazosin molecules to palladium ions in the colored complex was found to be 1: 1. Finally, a procedure for the determination of PZH in pure form or in pharmaceutical preparations is recommended. The method is selective, sensitive and accurate

Spectrophotometric determination of amikacin through its complication with cu [II] ion

A spectrophotometric method was developed for the determination of amikacin in pharmaceutical forms. The method depends on its complexation with Cu [II] ions, in slightly alkaline medium using tartrate as an auxiliary ligand. It was found that Cu [II] complexes with amikacin in the ratio 1:1 [Cu: amikacin], and the value of log beta 1 constant of the complex was found to be 6.8. The proposed method was used for the estimation of amikacin in pharmaceutical preparations with suitable accuracy