Development and Evaluation of Acyclovir-Loaded Ophthalmic Lyophilisate Carrier System: Design, Characterization, and In Vivo Ocular Tolerability Assessment

The objective of this study was to develop and evaluate an acyclovir-loaded ophthalmic lyophilisate carrier system, aimed at enhancing ocular drug delivery for the treatment of viral eye infections. Acyclovir, an antiviral agent, is often prescribed for ocular herpes simplex virus infections, but its ocular bioavailability is limited due to rapid drainage and poor permeability. To address these limitations, a novel lyophilized formulation was designed using biocompatible and biodegradable polymers as carriers to prolong the retention time and facilitate sustained release of the drug at the site of infection. The acyclovir-loaded lyophilisates were prepared using a freeze-drying technique, with optimization of the formulation parameters including polymer concentration, cryoprotectants, and lyophilization conditions. The characterization of the lyophilized systems included evaluation of physical properties, drug content, reconstitution behavior, morphology, and in vitro release profiles. The formulations exhibited high drug entrapment efficiency, desirable rehydration properties, and sustained drug release over an extended period. In vivo ocular tolerability of the developed system was assessed in a rabbit model. The formulations showed good ocular compatibility with minimal irritation or inflammation, indicating their potential for safe and effective use in ocular therapy. The pharmacokinetic study revealed enhanced corneal retention and prolonged drug release compared to conventional aqueous solutions. This study demonstrates the potential of acyclovir-loaded ophthalmic lyophilisate carrier systems for improved ocular drug delivery. The developed formulation provides a promising alternative to conventional therapies, offering prolonged ocular residence time, improved drug bioavailability, and minimal side effects, thereby enhancing the therapeutic efficacy of acyclovir in treating viral ocular infections. Further clinical studies are warranted to confirm these findings and explore the potential for broader clinical application.