NATURALLY OCCURING CLAY, MONTMORILLONITE, AS A DRUG DELIVERY VEHICLE FOR IN VITRO EXTENDED RELEASE OF VENLAFAXINE HYDOCHLORIDE

Abstract

Normal 0 In the present work, a naturally occurring smectite group clay mineral, Montmorillonite, (Mt) has been explored as a vehicle for delivery of an antidepressant drug Venlafaxine hydrochloride, VF. The effect of pH of the drug solution, time and initial drug concentration on drug loading capacity of Mt has been studied. The adsorption isotherm was fitted by the Langmuir model and follows the pseudo-second-order kinetics. The synthesized Mt-VF complexes were characterized by XRD, FTIR, TGA, DSC etc. VF was found to be intercalated in the Mt layers. The release profile of the VF and Mt-VF complex in simulated gastric and intestinal fluids has been discussed. The release behaviour of VF from Mt-VF complexes appears to be sustained/ extended for a period of 12 h and reaches upto 52% in simulated gastric fluid and is stable in intestinal fluid where as pure VF completely gets released in 5.5 h and 3.5 h in simulated gastric and intestinal fluid respectively Out of all kinetic models used to elucidate the drug release mechanism, the best fitting was observed for first order model. On the basis of present studies it can be stated that the synthesized Mt-VF complexes have the potential for developing in to a sustained release formulation for oral drug delivery of an anti-depressant drug VF. This shows a path which can reduce doses substantially from 4 times in 24h to twice in 24 h.