Study on the dissolution improvement of albendazole using reconstitutable dry nanosuspension formulation

Abstract

The aim of the study was to improve the solubility and dissolution rate of the poorly water soluble drug albendazole via surfactant assisted media milling process. Preparation of a nanosuspension and then post-processing with a solidification technique applied to improve the applicability of nanosuspension in a solid dosage forms carrier. The dry nanosuspension was obtained using microcrystalline cellulose as solid carrier after tray drying at 40 °C. Both reconstitution from the solid carrier and dissolution profile studies were investigated in biorelevant Artificial Rumen Fluid (ARF) at pH = 6.50 and dissolution media at pH = 1.20 and pH = 6.80. Reconstitution studies have demonstrated that the mean hydrodynamic diameter values of albendazole crystals released from the dry suspension were nanosized (intensity weighted hydrodynamic diameter values: 200.40 ± 2.318 nm in ARF at pH = 6.50, 197.17 ± 0.208 nm in dissolution medium at pH = 6.80). Thermodynamic solubility studies have indicated a 2.98 times increase in water solubility (144.41 ± 0.09 μg/ml milled, 48.38 ± 0.01 μg/ml unmilled, 8.21 ± 0.02 μg/ml albendazole powder) in ARF at pH = 6.50, and 2.33 times in dissolution medium at pH = 6.8: (146.27 ± 0.28 μg/ml milled, 62.71 ± 0.04 μg/ml unmilled, 9.00 ± 0.01 μg/ml albendazole powder), and 13.65% increase at pH = 1.20 (1728.31 ± 3.31 μg/ml milled, 1559.41 ± 0.40 μg/ml unmilled, 1520.70 ± 1.39 μg/ml albendazole powder), dissolution rates have also increased. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) imaging investigations detected no albendazole nanocrystals on the surface of the carrier, which demonstrated the incorporation of albendazole into the microcrystalline cellulose solid carrier structure.