Synthesis, characterization and in vitro release studies of a new acetazolamide–HP-β-CD–TEA inclusion complex

The aim of our work was to develop a multicomponent inclusion complex of acetazolamide (ACZ) in order to investigate the combined effect of hydroxypropyl-β-cyclodextrin (HP-β-CD) and triethanolamine (TEA) on the solubility of ACZ and its possibility of ophthalmic delivery. Phase solubility study was used to evaluate the complexation in solution at 25 °C. Complex formation was also evaluated by comparing the infrared (FT-IR) spectra of the solid complexes with a simple physical mixture containing the same amount of ACZ. FT-IR experiments provided data indicating that the carbonamido group of ACZ is involved in the inclusion process. In vitro release data showed that both formulations, containing the freeze-dried ternary complex and the corresponding simple physical mixture of ACZ with HP-β-CD and TEA presented the fastest release rate of ACZ. These results suggest that the ACZ–HP-β-CD–TEA complex represents an effective novel formulation to enhance ACZ solubility in water, turning it promising for ophthalmic administration.

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