Chitosan/Poly(2-ethyl-2-oxazoline) Films with Ciprofloxacin for Application in Vaginal Drug Delivery

Chitosan (CHI) and chitosan/poly(2-ethyl-2-oxazoline) (CHI/POZ)-based films were prepared by casting from aqueous solutions of polymer blends with different compositions. Ciprofloxacin was used as a model drug in these formulations. The weight, thickness, folding endurance and transparency of blend films were measured and characterised. All films had a uniform thickness (0.06 +/- 0.01 mm) and exhibited sufficient flexibility. The surface pHs of films ranged from 3.76 +/- 0.49 to 4.14 +/- 0.32, which is within the pH range suitable for vaginal applications. The cumulative release of the drug from the films in experiments in vitro was found to be 42 +/- 2% and 56 +/- 1% for pure CHI and CHI/POZ (40:60) films, respectively. Drug-free chitosan/poly(2-ethyl-2-oxazoline) films showed weak antimicrobial activity against Escherichia coli. Drug-loaded CHI and CHI/POZ films showed good antimicrobial properties against both Gram-positive Staphylococcus aureus and Gram-negative bacteria Escherichia coli. Mucoadhesive properties of these films with respect to freshly excised sheep vaginal mucosa were evaluated using a tensile method. It was established that all films were mucoadhesive, but an increase in POZ content in the blend resulted in a gradual reduction of their ability to stick to vaginal mucosa. These films could potentially find applications in vaginal drug delivery.