Thermosensitive Liposomal Gel as an Ocular Delivery System Physical, microbiological and in vivo assessments

The liquid retentive dosage form based on phase change thermosensitive polymer represents a promising drug delivery strategy to overcome ocular biopharmaceutical constraints. The present work describes the formulation and in vitro evaluation of ciprofloxacin HCl loaded liposomes dispersed in poloxamer 407 temperature triggered in situ gel. The antimicrobial activity of the prepared liposomal gel was thoroughly investigated, and the in vivo efficacy of the prepared gel was studied utilizing an induced bacterial conjunctivitis model. The results obtained pointed out that liposomes dispersed in poloxamer 407 in situ thermosensitive gel demonstrated a prolonged release over 24 h, with a pseudoplastic flow pattern. The microbiological investigation and the in vivo evaluation demonstrated the efficacy of liposomal gel as ocular drug delivery system. Moreover, the system studied was successful in inhibiting the growth of Pseudomonas aeruginosa in rabbit eyes for 24 h, whereas a value of 4 h was obtained for the marketed preparation used for comparison. In conclusion, the ease of administration coupled with the capability of providing a sustained release formulation resulted in a decrease in administration frequency, which improved patient compliance.