Solving the Delivery Problems of Triclabendazole Using Cyclodextrins

Triclabendazole is the first-line drug of choice to treat and control fasciolasis, a neglected parasitic human disease. It is a class II/IV compound according to the Biopharmaceutics Classification System. Thus, the aim of this study was to improve aqueous solubility and dissolution rate of triclabendazole complexed with 2-hydroxylpropyl-β-cyclodextrin (HP-β-CD) and methyl-β-cyclodextrin (Me-β-CD) at 1:1 and 1:2 M ratio. The impact of storage on the solubility, dissolution profile, and solid-state properties of such complexes was also investigated. Drug-carrier interactions were characterized by infrared spectroscopy, differential scanning calorimetry, X-ray diffractometry, and scanning electron microscopy. The solubility of triclabendazole improved up to 256- and 341-fold using HP-β-CD and Me-β-CD, respectively. In particular, the drug complexed with Me-β-CD showed a positive deviation from linearity, suggesting that its solubility increases with an increasing concentration of Me-β-CD concentration in a nonlinear manner. The drug dissolution was found to be improved through complex formation with HP-β-CD and Me-β-CD. In particular, the 1:2 M ratio complexes exhibited higher dissolution than the corresponding 1:1 M ratio complexes. The physicochemical characterization of the systems showed strong evidence of amorphous phases and/or of the formation of an inclusion complex. Stored at 25 °C, 60% RH for 24 months, drug complexed with β-cyclodextrins (CDs) at 1:2 M ratio remained amorphous. Based on these findings, it is postulated that the formation of triclabendazole-CD inclusion complexes produced significant enhancement in both the dissolution and solid-state properties of the drug, which may lead to the development of triclabendazole novel formulations with improved biopharmaceutical characteristics.