VISCOMETRIC STUDY OF SYNTHESIZED DILTIAZEM-VANADIUM (V) COMPLEX IN NON-AQUEOUS SOLVENTS

In the present research work, measurement of viscometric parameters – Density, Molar Volume, Apparent Molar Volume, Viscosity, Specific Viscosity, and Fluidity of synthesized Vanadium (V) complex of commercial antihypertensive drug, Diltiazem has been reported in non-aqueous solvents of varying compositions. Composition of non-aqueous solvents selected for study is 20% and 40% methanol-water mixture. Experimental results showed the effect of Concentration of solute (Diltiazem drug) on density and viscosity in a methanol-water mixture. The density of Diltiazem-V (V) complex showed an irregular pattern in 20% methanol-water mixture, whereas an increase was observed in 40% methanol-water mixture. The molar volume value for the complex solution in both 20% & 40% methanol-water mixture showed rapid increase with the increase in complex Concentration. The apparent molar volumes (φ_v) decreased with an increase in Concentration of complex and same trend was followed in both 20% and 40 % methanol-water solvent system. Study of the viscous behavior of complex molecules in solution gives an understanding of the transport process mechanism and information about the shape and size of molecules. Specific viscosity ‘ηsp’ values of diltiazem-V(V) in 20% and 40% methanol-water mixture show that it raises with a rise in complex Concentration. This in turn gives a picture of molecular interactions taking place in different solutions. Information about molecular interactions between a metal complex of drug and various solvent compositions helps in the formulation of the stable, effective, and safe dosage form. It also helps in the understanding of their oral absorption by increasing the solubility or dissolution rate.