Spectrophotometric Determination of Some Cardiovascular Drugs Using P-Chloranilic Acid

Abstract

A simple and sensitive spectrophotometric method for the assay of some cardio-vascular drugs is described. The method is based on the interaction of the drug and p-chloranilic acid (p-CA) to give a stable and intensively coloured ion-pair salt. The drugs used are quinidine sulphate, prenylamine lactate, dipyridamol, hydralazine hydrochloride, tolazoline hydrochloride and pindolol. The optimum experimental conditions for colour development have been studied. Conformity to Beer's law enabled the determination of these drugs in their pharmaceutical preparations. The assay results are in accord with the pharmacopoeal assay results.     

Ultraviolet Spectrophotometric Determination of Primary Amine-Containing Drugs via Their Charge-Transfer Complexes with Tetracyanoethylene

A spectrophotometric method is described for the quantitative determination of some drugs containing a primary amino-group, i.e. amantadine hydrochloride, tranylcypromine sulfate and tranexamic acid in their pure forms as well as in some pharmaceutical dosage forms. The procedure is based on the formation of a charge-transfer complex between tetracyanoethylene (TCNE) as -acceptor and the studied drugs as n-donors in the presence of acetonitrile as solvent. The spectra of the complexes show maxima at 330nm with high apparent molar absorptivities (from 2.1 × 10³ to 2.2 × 10⁴ L·mol^–1 cm^–1). Beers law is obeyed in the concentration ranges of 25–75 µg mL^–1, 2–30µgmL^–1 and 5–25µg mL^–1, and the mean percent recoveries are 99.68±0.92, 100.3±0.75 and 99.8±0.76 for amantadine hydrochloride, tranylcypromine sulfate and tranexamic acid, respectively. The proposed method is simple and can be applied to determine these drugs in their pharmaceutical dosage forms. The results compare favorably with those of reported methods.