Development of oral liquid dosage forms of acetazolamide

Two oral liquid dosage forms of acetazolamide have been developed. Using the solubility profiles, polyethylene glycol 400 (7%, v/v) was used as the solubilizing agent and propylene glycol (53%, v/v) as the cosolvent to keep acetazolamide in solution. Because of the bitter taste of acetazolamide, sweetening agents (simple syrup, sorbitol solution, and artificial sweeteners) and flavors (raspberry, sweet, and menthol) were added to the final formulations. A buffer (either phosphate or citrate) solution was used to maintain a pH value of 4 (pH of maximum stability as reported earlier) to minimize hydrolysis. The final dosage forms were stable for at least 90 days at 37 degrees C (loss of potency of 5%). According to FDA guidelines, a tentative expiry date of 2 years at 25 degrees C is justifiable.