Design, fabrication and characterisation of drug-loaded vaginal films: State-of-the-art

Abstract

Films have undoubtedly seen the most significant advances in their development in recent years of all the pharmaceutical forms for the vaginal administration of drugs. Films combine the advantages of gels and solid pharmaceutical forms, and their great versatility is largely determined by the numerous polymers that can be used for their fabrication. They may be based on many natural polymers, and cellulose derivatives, polyvinyl alcohol or acrylic derivatives - among others - are also frequently used. The combination of different polymers and the inclusion of plasticizing agents makes them extremely versatility for responding to a range of therapeutic needs. The techniques used to produce films have also undergone substantial development. Although the solvent casting technique is by far the most widely used in fabrication, alternative options have also emerged such as electrospinning, moulding extrusion and 3D printing. Various research groups have proposed a proliferation of assays to characterise vaginal films in recent years, which highlight the importance of the preliminary evaluation and determination of the films' uniformity, in addition to tests to determine their permeability and hydrophilic/hydrophobic coefficient and their mechanical properties, the application of imaging techniques and thermal analysis, and especially the evaluation of the mucoadhesive properties and control over the drug release. This article offers a critical overview of the advances in the development and fabrication of films intended for vaginal drug delivery, and summarises current clinical applications for vaginal films.

Keywords: Drug delivery; Film characterisation; Film fabrication; Film-forming ingredients; Therapeutic applications; Vaginal films.