Coprocessed excipients of crosslinked amylose and xanthan gum for use in controlled release dosage forms

Objective: This study was aimed to obtain a new excipient that can be used as a polymer matrix for the formulation of controlled release dosage forms. Methods: This study used coprocessing and crosslinking methods on amylose and xanthan gum (XG) to obtain a new excipient that can be used for controlled release matrix of pharmaceutical dosage forms. The coprocessing step was conducted by drum drying, and the crosslinking step was prepared using 6 and 12% sodium trimetaphosphate (STMP). The produced novel excipients were characterized in terms of infrared (IR) spectrum, substitution degree, moisture content, swelling index, and gel strength. Results: Our results showed that amylose-XG excipients crosslinked using 6% STMP have greater gel strength and better swelling indexes than excipients crosslinked using 12% STMP. All coprocessed excipients exhibited no differences in their IR spectra, whereas the crosslinked excipients did, indicating a structural change due to the addition of phosphate groups. Crosslinking amylose-xanthan-coprocessed excipients using 6% STMP produced degrees of substitution (DSs) of 7-8 phosphates per 100 monomeric subunits. The excipients had a moisture content of 8.21-12.85%, and the pH of a 1% solution of excipients was 6.21-6.43. In addition, the swelling index and gel strength of the excipient where both amylose and XG were crosslinked together Were more than 1 where only amylose was crosslinked. Conclusion: The crosslinking amylose-xanthan-coprocessed excipient using 6% STMP is more suitable for use in controlled release dosage forms, particularly when the polymer ratio is 1:1.