Spectroscopic and electrochemical analysis of psychotropic drugs.

Psychotropic drugs are an important family of compounds from a medical point of view. Their application in therapy requires methods for the determination in pharmaceutical dosage forms and body fluids. Several methods for their analysis have been reported in the literature. Among the methods, spectrophotometric and electrochemical are very useful for the determination of the drugs. Some of the spectrophotometric methods are based on the formation of the binary and ternary compounds with complexes of metals. The formed compounds are sparingly soluble in water, but quantitatively extracted from aqueous phase into organic solvents and the extracts are intensely colored and stable for a few days. These complexes have been employed in pharmaceutical analysis. The electrochemical procedures are very useful in determination of the psychotropic substances in pharmaceutical preparations.

Application of ammonium peroxidisulfate and metavanadate for spectrophotometric determination of prothipendyl hydrochloride.

Prothipendyl hydrochloride reacts with (NH4)2S2O8 and NH4VO3 forming the coloured oxidation products which exhibit maximum absorbance at lambda = 372 nm and 374 nm, respectively. The optimum conditions of the reaction have been established. It was found that Beer's law is obeyed in the concentration range 3-95 microg/ml and 3-90 microg/ml in PTP-(NH4)2S2O8 and PTP-NH4VO3 system, respectively.

Examination of iron (III) and hexacyanoferrate (III) ions as reagents for the spectrophotometric determination of promazine and perazine.

Iron (III) chloride and potassium hexacyanoferrate (III) have been tested as reagents for the determination of promazine hydrochloride and perazine. The methods are based on the oxidation of phenothiazines by FeCl3 and K3[Fe(CN)6] in perchloric acid medium. The optimal conditions for the formation of oxidation products of promazine and perazine were examined. The absorption spectra in the UV-VIS region were recorded.

Determination of chelate complexes by spectrophotometry; L-ascorbic acid with cadmium (II) and zinc (II) in alkaline solution.

The chemical behaviour of L-ascorbic acid (H2Asc) with cadmium (II) and zinc (II) in alkaline medium was studied. The total stability constants of the examined complexes and their composition were determined by spectrophotometry (Jacymirsky and computer) method. An attempt has been made to explain the nature of complexes formed in the systems Cd (II)-H2Asc-H2O and Zn (II)-H2Asc-H2O and the interaction between these compounds.

Spectrophotometry assay of imipramine and desipramine using ammonium metavanadate and its application to pharmaceutical preparations.

Simple and sensitive method for determination of imipramine and desipramine is reported. The procedure is based on the oxidation of the drugs by ammonium metavanadate. Linear calibration graphs were obtained in the concentration range 0.6-40 microg ml(-1) of imipramine and 0.7-35 microg ml(-1) of desipramine with a relative standard deviation (RSD) less than 0.5%. The method was applied to the determination of the drugs in pharmaceutical preparations and compared favourably with independent official methods.