Development of microemulsifying systems involving bisphosphonate

The aim of this study was to develop ALD microemulsion system that is selected as active drug and has bioavailability problem and evaluate the amount of radioactive ALD and non-radioactive ALD for permeability studies. Oral microemulsion formulations were tested by using various surfactant, cosurfactant, oil and water phase and w/o type microemulsion formulation was determined as ideal formulation by the help of pseudo ternary phase diagram studies. Physicochemical properties and stability of the ideal ALD microemulsion formulation were evaluated. At the end of stability studies, ALD microemulsion formulation has been found to be stable. The 10 g of ideal microemulsion contained 0.78 g of soybean oil as an oil phase, 2.85 g of Tween 80 and 0.15 g of Cremephor EL as surfactant, 3 g of Transcutol as co-surfactant, 3.22 g of physiological serum. ALD initially marked with 99mTc was added to new microemulsion formulation. Labeling efficiency, the radiochemical purity and stability of the radiolabeled ALD microemulsion were examined by using thin layer chromatography. The labeling efficiency of developed ALD microemulsion formulation was greater than 90% and ALD marked with 99mTc microemulsion formulation was observed to be stable at room temperature for 6 hours. The permeability studies were carried out by in vitro cell culture studies. The permeability of microemulsion formulations containing ALD labeled with 99mTc and non-radiolabelled ALD were examined with Caco-2 cells. The permeability from apical to basolateral direction was found greater than the permeability from basolateral to apical direction. Consequently, labeled with 99mTc and non-radiolabelled ALD microemulsion was developed as ideal formulation and can be used as an alternative to commercially available other bisphosphonate group drugs.