Abstract
Background: Bacterial infections of the eye are treated by administering ophthalmic solutions containing corticosteroids and antibacterial agents. The main challenges faced when used for topical instillation are precorneal fast clearance and multiple applications, particularly with gatifloxacin. Objectives: To develop an ocular gel that utilizes both ion-induced and thermal-sensitive mechanisms to achieve gelation. Methods: We prepared and compared formulations containing different percentages of poloxamer 407 and gellan gum (F1–F24) in terms of gelation temperature, gelling capacity, gelation time, and permeation. We tested the optimum formulation for isotonicity and irritation in rabbits. Results: The formulations' pH varied from 6.7 to 7.3. Formulations that passed the gelation temperature test successfully were F6, F7, F9, and F10. For both drugs (F6, F7, F9, and F10), the drug content percentages ranged from 98.64% to 99.95%. In situ, gels (F6, F7, F9, and F10) showed pseudoplastic shear-thinning rheological behavior, which means that their viscosity decreased as the angular velocity went up. F7, which contains 17% poloxamer and 0.5% gellan gum, had 15 seconds of gelation time at 34oC and remained in gel form for 270 min. It was isotonic and did not change the size or shape of RBCs when topically applied. The rabbit's eyes did not experience irritation due to the extended release of both drugs. Conclusions: The new in situ gel formulation may be a superior alternative to the traditional eye drops of gatifloxacin and betamethasone for ocular infections.
Publisher
Al-Rafidain University College