SPECTROPHOTOMETRIC DETERMINATION OF DILTIAZEM IN PHARMACEUTICAL AND IN-VIVO SAMPLES WITH Pd(II)

An analytical method has been developed for quantitative determination of diltiazem, chemically (+)-cis-1,5-benzothiazepin-4-(5H)one, 3-(acetyloxy)-5-[2-(dimethyl amino)ethyl]-2,3-dihydro-2-(4-methoxyphenyl)-monohydro chloride, by complexation with Pd(II) spectrophotometrically. Diltiazem is a calcium channel blocker type antihypertensive drug.  Diltiazem forms an stable orange colored 1:2 complex with Palladium(II) Chloride with lmax 400nm, molar absorptivity coefficient of complex  e=  8.5 X10² l mol^-1cm^-1, Beer’s law range 3.413 X10¹ mg/ml to 2.722 X10² mg/ml  with intercept of regression 0.019 and correlation coefficient  0.989. Interference of foreign metal ions and effect of temperature and pH was also studied. The characterization of complex involves, Elemental Analysis, FTIR, ¹H NMR, ESR, Raman spectra, magnetic susceptibility measurement and thermal studies. On the basis of above studies structure of the complex has been proposed. The developed analytical method was applied on in-vivo blood samples- whole blood and serum samples. For whole blood samples Beer’s law range is 1.01 X 10² mg/ml to 2.77 X 10² mg/ml with coefficient of variance ±1.49 and relative standard deviation 0.64% and for serum samples Beer’s law range is 1.79X10² mg/ml to 2.47 X 10² mg/ml with coefficient of variance ±1.03 and relative standard deviation 0.79%. The procedure is rapid, accurate with precision and can be used by pathologists and in industrial sectors for determination and quality test of diltiazem in pharmaceutical samples.