OCULAR BOAVAILABILIIY OF TRIAMICINOLONE ACETONIDE COMPLEX FROM DIFFERENT OPHIHALMIC PREPARATIONS IN RABBITS’ EYES

Abstract

The effect of beta-cyclodextrin (β-CyD) on the solubility , release characteristics and ocular bioavailability of triamcinolone acetonide (TA) from ophthalmic gels and ocuserts were investigated. Triamcinolone acetonide- β-CyD complex was prepared by kneading method in a molar ratio of 1:1. The ophthalmic gels [carbopol 934. hydroxy propy] methyl cellulose (HPMC). sodium alginate| and ocuserts (HPMC and carbopol 934 combination. sodium alginate and carbopol 934 combination) were prepared using 0.1% of the drug or its equivalent amount of complex with β-CyD. The in vivo study was performed on male albino rabbits. The drug concentrations were determined in different eye tissues and aqueous humor of the rabbits after 1. 2.4. and 6 hr of the application by HPLC method. The obtained results revealed that. the solubility of TA was increased linearly as a function of β-CyD concentration following AL type phase solubility diagram. The percent released of the drug from the prepared formulations containing free TA could be arranged in the following order: HPMC and carbopol 934 combination ocuserts > sod. alginate and the percent released of the drug from ophthalmic gels and ocuserts containing the drug complex with β-CyD was significantly higher than that of the free drug. Concerning the ocular bioavailability, all tested formulations provided the highest Cmax Of the drug in conjunctiva folloWed by cornea, i is-ciliary bod!. then the aqueous humor. except that after 6 hr. it was high in cornea followed by iris-ciliary body. conjunctiva and then the aqueous humor. The peak time of maximum drug concentration (Tmax) in rabbits eye tissues and aqueous humor was 4 hr for all ophthalmic gels and ocuserts. The total ocular bioavailability of triamcinolone acetonide was improved when the drug was complexed with β-CyD.