Evaluation of Physico-Mechanical and Mucoadhesive Properties of Biopolymer Films From Cola Acuminata Gum

Abstract

Background: Applications of film-forming materials in coating technology and drug delivery systems has led to several investigations into the film-forming potential of different polymers. A good film-forming material must possess good mechanical strength, wetting and adhesive properties
Objective: This study investigated the physico-mechanical and bioadhesive properties of biopolymer films from Cola accuminata pods, obi (Yoruba), oji (Ibo) and gworo (Hausa).
Methodology: The Cola acuminata gum (CAG) was extracted by soaking the sliced pods in distilled water and precipitating with acetone. Plasticizer-free CAG mucilage (10% w/v) was prepared using aqueous dispersion method. Similar batches of CAG mucilage containing plasticizers - propylene glycol (PPG) or glycerin (G) at concentrations of 1 - 3% v/v of the mucilage were also prepared using the same method. The mucilage samples were cast into films on Petri dishes by drying at 60^o C for 12 hours. Films with satisfactory texture were subjected to various physical tests. The mechanical properties of the films were assessed with Instron Universal Tester instrument (Model 3369) followed by folding endurance test. Ex-vivo mucoadhesive evaluation of the films was also conducted using Instron Probe Tack Tester (Model 5569).
Results: All the films were brown and odourless. The plasticizer-free film (F1) was dry and brittle, while F4 - F6 remained wet and tacky. Films containing 1% and 2% v/v of PPG (F2) and (F3) respectively were smooth, flexible, hydrophillic in nature and exhibited pH dependent mucoadhesion and swelling properties in aqueous medium. Swelling index increased with increase in PPG concentration but reduced the mucoadhesive strength of the films.
Conclusion: The CAG possessed good film-forming and mucoadhesive properties. It can be used as a coating agent for sustained release, pH dependent and mucoadhesive and topical drug delivery system.

Keywords: Mucoadhesive, Plasticizers, Ex vivo, Film - forming