Abstract

Glibenclamide is a second generation sulfonyl urea compound used as an oral hypoglycemic or anti diabetic agent, a class of drug used to treat type-2 diabetes mellitus. The bilayer lipid membrane systems have been employed extensively as an experimental model of bio membranes. It is of major importance in medical research, particularly in the study of mechanism of a number of life saving therapeutic agents where a lipid bilayer is the primary site of interaction. The objective of this study was to investigate the transport of glibenclamide across micro-pore supported model bilayer lipid membrane. In this study, lipid bilayer membrane was prepared from L-alpha - phosphotidylcholine. Conductometric and potentiometric techniques were used to measure membrane conductance and membrane potential respectively as a function of concentration of the glibenclamide solution and temperature of the electrochemical cell maintained. The observed data were used to evaluate selectivity and activation parameters by making use of mathematical expressions derived on the basis of non-equilibrium and transition state theories. From membrane potential study, thermodynamically effective fixed charge density (ØX) and transport number of anions (t-) obtained were 42.6 meq/lit and 0.76 respectively and membrane conductance of 0.1 molar glibenclamide drug solution at 37°C showed 26.11 + 0.01 (µs/cm), at this concentration and temperature values of activation parameters (Ea, ΔG*, Δ H*, -ΔS*) obtained were: 2516.47J/mole, 61605.71 J/mole,38.90J/mole and 206.60 J/k mole respectively. The observed and evaluated data indicated that selective membrane behavior was more pronounced in the dilute range and the drug molecules were diffused across the membrane passively. Hence it might be concluded that small amount of drug is more effective in getting the desired effect.

Key words:  Glibenclamide, model membrane, electro analytical methods.