In vivo study of promising formulated ocular bio-adhesive inserts of ciprofloxacin hydrochloride combination with xanthan gum and carbopol

Objective: To study the in vivo behaviour and irritant properties of different ocular bio-adhesive inserts of ciprofloxacin hydrochloride (CFX-HCl) prepared using a spray dried (SD2) matrix system consisting of xanthan gum, carbopol, and propylene glycol.

Methods: CFX-HCl in aqueous humor samples was analysed using HPLC method. Applying a mobile phase of 0.01M sodium acetate: methanol (70:30 v/v) with pH around 3.00, and using Purosphere star 100RP-18 column (125 mm × 4.6 mm × 5 µm). The in vivo behaviour and irritant properties of ocular inserts was studied on rabbits. Twelve rabbits were used for the study and were divided into four groups. After placing the insert in the eye 100 µl of the aqueous humor was withdrawn at different time intervals in order to measure the concentration profile of CFX-HCl. The tested formulae R, F1, F2, and F3 were all containing 6.25 mg of CFX-HCl.

Results: The method was well validated according to linearity, recovery, and precision. Where the calibration curve was linear over a concentration range of (2.500–7.826) µg/ml, with an average recovery of 99.76%. The presence of the matrix system enhances the absorption of CFX-HCl and sustains its release up to four days leading to increasing its bioavailability. Also, the ocular inserts of F2 and F3 have better biocompatibility compared with R and F1.

Conclusion: The analysis method was found sensitive, accurate and precise and could be used to assess the in vivobehaviour of CFX-HCl. The ratio of the free drug to the matrix system controlled the rate of drug release.