Alendronate-loaded microparticles for improvement of intestinal cellular absorption

This study examined a novel alendronate formulation that was developed to overcome the shortcomings of alendronate, such as its low bioavailability and gastric adverse effects. Alendronate microparticles were prepared using mucoadhesive polymers such as chitosan for improving the intestinal cellular absorption of alendronate and also using a gastric-resistant polymer such as Eudragit L100-55 for reducing the gastric inflammation of alendronate. Alendronate microparticles including chitosan showed a threefold increase in alendronate uptake (6.92 ± 0.27%) in Caco-2 cells when compared with the uptake of alendronate solution (2.38 ± 0.27%) into Caco-2 cells. Most interestingly, alendronate microparticles including chitosan showed 2.80 x 10⁻⁶ cm/s of an apparent permeability coefficient across Caco-2 cells and caused a significant 42.4% enhancement compared with that of alendronate solution across Caco-2 cells. The morphology of the Caco-2 cells treated with alendronate microparticles including chitosan was similar to that of the untreated cells and alendronate microparticles exhibited a negative effect to propodium iodide with some annexin-V fluorescence isothiocyante positive effect. It was proposed that the novel alendronate microparticles could possess the potential of an increased intestinal absorption and fewer adverse effects of alendronate.