Determination of Amineptine and Amprolium Hydrochlorides through Ion Associates with Cobalt (II) Thiocyanate

Two new methods for the determination of amineptine (AMN) and amprolium (AMP) have been developed. The methods consist of extractin the ion - pairs between the drug and the inorganic complex [Co (SCN)4]−2. The optimal experimental conditions of both methods including pH, concentration of Co (II) and tlxocyanate ions, and the organic solvents were studied. The optimum pH was found to be 3.9, nitrobenzene proved to be the most suitable solvent, giving quantitative extraction for the two drugs. The two drugs can be determined in the organic phase spectrophotometrically at 625 nm showing Sandell sensitivities of 0.19 and 0.12 µg cm−2 with relative standard deviation of 0.46 and 0.87 % for amineptine and amprolium, respectively.The indirect method was also applied to measure cobalt in the organic phase by atomic absorption spectrometry at 240.7 nm, and the relative standard deviation of the method is approximately 0.35 and 0.29 % for amineptine and amprolium, respectively. The proposed methods were found to be suitable for the accurate, simple and rapid analysis of amineptine and amprolium hydrochlorides in the bulk drugs and in pharmaceutical forms.