ABSTRACT
Ciprofloxacin hydrochloride [CPX-HCL] ophthalmic solutions were formulated using different, polymers, buffers and antioxidants. The polymer solutions tested were sodium carboxy methylcellulose [SCMC] 0.1%, hydroxypropyl methylcellulose [HPMC] 2%, methylcellulose 400 [MC] 0.6%, polyethylene glycol 6000 [PEG] 10%, polyvinyl alcohol [PVA] 2% and polyvinylpyrrolidone K25 [PVP] 10%. [CPX-HCL] gave clear solutions with only [MC] and [HPMC] at the same pH range of other tested polymers. Also, the acetate buffer [pH 4.8] was the only suitable buffer for forming a stable ophthalmic solution. The results also revealed that 0.05% is the optimum EDTA concentration as antioxidant. Consequently, the eye drops were prepared with 0.6% MC and 2% HPMC in distilled water or in presence of acetate buffer [pH 4.8]. Benzalkonium chloride [0.004%] was added in all formulae and the isotonicity was adjusted by sodium chloride. The stability of the four formulae was investigated for 24 months at different temperatures [4C, 37C and 45C]. The drug showed greater stability in acetate buffer than in double distilled water. The formula prepared with HPMC in acetate buffer exhibited the highest stability at all tested temperatures. This formula showed reduction in drug potency by 94.69, 91.09 and 86.01% after storage for two years at 4C, 37C and 45C, respectively. All formulae showed reduction in drug potency to about 85% of its initial potency after storage for 14 days in presence of light at room temperature. The low density high density polyethylene plastic containers and amber colored glass showed insignificant difference on drug stability