Preparation of Gatifloxacin Microparticles by Double Emulsification W/O/W Method for Ocular Drug Delivery:Influence of Preparation Parameters

The purpose of the present study was to prepare microparticles containing Gatifloxacin suitable for ocular drug delivery. Polycaprolactone microparticles were prepared using the double emulsion (water-in-oil-in-water) solvent extraction/evaporation method. Two different modified methods were applied and the influence of their preparation parameters on the final microparticles properties was studied in an attempt to control particle sizes and encapsulation efficiency. By adjusting formulation and process parameters, we uncovered that using of 3% (w/v) PVA as emulsion stabilizer in the internal aqueous phase (first studied process) facilitated microparticles (77% of particles more than 100μm in size) which is suitable for oral drug delivery, but with highest entrapment efficiency EE% (82.12%). Whereas introducing 5% (w/v) of PVP as stabilizing agent and 5% (w/v) of NaCl as osmotic balancer in the external aqueous phase (second studied process) afford microparticles which is optimal in size for ophthalmic drug delivery (95% of particles less than 25μm in size) with an acceptable EE% (30.18%).The later result demonstrated that, this colloidal system could be developed in order to use as drug carriers for ocular drug delivery, which offers several advantages including longevity, stability and bioavailability of encapsulated drug. Moreover, it seemed to be applicable for sustained ocular drug delivery allowing minimizing dose repetition to reduce systemic side effects and enhance patient compliance.