Polymeric films as a promising carrier for bioadhesive drug delivery: Development, characterization and optimization

Abstract

Bioadhesive films using tamarind seed polysaccharide were prepared for the treatment of candida vaginitis using nystatin as the model drug. Films were prepared by solvent casting method. A 3² factorial design was employed to study the effect of independent variables (polymer and plasticizer concentration) on a range of dependent variables namely mechanical, swelling, interfacial, and bioadhesive properties through response surface methodological approach, using Design Expert® software. Formulation composition that provided the most desired and optimized results was selected using desirability approach. Nystatin was solubilized using Tween 60 and was incorporated into the selected film. Drug solubilization and dispersion were confirmed by scanning electron microscopy and differential scanning calorimetry. The optimized film released 73.92 ± 2.54% of nystatin at the end of 8 h in simulated vaginal fluid and the release data showed best fit to Korsmeyer-Peppas model with R² of 0.9990 and the release mechanism to be super case-II. The optimized film also showed appropriate anti candida activity through appearance of zone of inhibition during antifungal activity testing study.

Keywords: Candidiasis; Polymeric films; Response surface methodology; Vaginal delivery.

Figure 1

Response surface plots for responses namely (a) contact angle, (b) spreading coefficient, (c) WVTR, and (d) swelling index.

Figure 2

Response surface plots for responses namely (a) tensile strength, (b) max detachment force, and (c) %EB (% elongation at break).

Figure 3

Overlay plot of all response variables showing the region of desirability.

Figure 4

Linear correlation plots between actual and predicted values for different check point formulations for different responses.

Figure 5

Physicochemical interactions between blank (T14) and drug loaded TSP films with nystatin and Tween in ratio of 1:0 (T14D), 1:0.5 (T14DT_0.5) and 1:1 (T14DT).

Figure 6

Surface morphology of blank (a), drug loaded TSP films with nystatin and Tween in ratio of 1:0 (b), 1:0.5 (c), and 1:1 (d).

Figure 7

Nystatin release profile for TSP films.