Investigation of Physico-Chemical Properties of Gelatin Matrices in Correlation with Dissolution Studies

Gelatin is a versatile biopolymer obtained from a partial hydrolysis of collagen. Gelatin is commonly used in formulation of pharmaceuticals and nutraceuticals, encapsulating the active ingredient. For these applications the dissolution profile of the matrix in the gastrointestinal tract (GIT) is of crucial importance. The dissolution of a gelatin matrix in the GIT may be seen as a two-step procedure: gel-sol transition of the gelatin network, followed by diffusion of the peptide strands from the concentrated matrix to the bulk liquid. Thus, it is clear that the melting temperature is important in gelatin gel dissolution investigations. Depending on the raw material (bovine or porcine sources) and extraction conditions, gelatins with wide variations in molecular size distribution – and therefore varying rheological properties/melting temperatures – may be obtained. Dissolution studies are generally time consuming and therefore it would be advantageous to predict the dissolution profile without performing in vitro measurements. The scope of this work was to evaluate if any of the physico-chemical properties of the gelatin matrices can be used to predict the dissolution profiles of the gelatin gels.