Molecular weight-dependent properties of ciprofloxacin-loaded chitosan films: An in-vitro comparative study toward localized drug delivery for wound healing.
Abstract
Targeted or localized delivery to wounds is essential to avoid unwanted systemic effects of antibiotics. Ciprofloxacin hydrochloride (CH) is a broad-spectrum fluoroquinolone antibiotic used to treat skin and soft tissue infections. In this study, polymeric films were prepared by solvent casting using different molecular weights of chitosan (CT) and suitable plasticizers, such as propylene glycol (PG) or glycerin (GLY), to investigate their physicochemical properties, antimicrobial efficacy, drug release behavior, and stability. Polymer chain length and plasticizer selection influenced the films' physicochemical properties. The SEM, FTIR, DSC, XRD, and contact angle measurements revealed the transformation of the crystalline drug into an amorphous state, accompanied by hydrogen bonding between the drug and the polymer. The films demonstrated significant antibacterial efficacy and effective quantitative antimicrobial and antibiofilm profiling against some clinically relevant Gram-negative and Gram-positive bacteria. The initial drug release was also affected by the polymer's molecular weight; however, a complete release was noted within about 2 hours. The films fit the zero-order model better, followed by the Higuchi and Korsmeyer-Peppas models. The Korsmeyer-Peppas release exponent (n) values showed a correlation between CH release behavior from films and multiple independent physical parameters, establishing a predictive structure-property-release framework. The drug and excipients were compatible with each other and with the aluminum packaging, with no detectable chemical degradation, for at least 6 months under both accelerated and real conditions using the employed method. Such tunability underscores the adaptability of CT-based films as promising pre-formulation candidates that require further biological evaluation for localized therapeutic applications, where targeted drug delivery and rapid antimicrobial effects are paramount.