Araucaria Gum: Novel Natural Polymer for Controlled Drug Delivery. Development, In Vitro and In Vivo Evaluation of Araucaria Gum Based Matrix Tablets for Controlled Release.

Abstract

Assessment of natural polymers in oral controlled drug delivery. The objective of the present investigation was to assess of Araucaria gum (AHG) obtained from bark exudates of the Araucaria heterophylla (family: Araucariaceae) for the design of oral controlled release forms, in particular tablet dosage forms by using matrix systems. Diclofenac sodium was used as model drug and compared with the marketed formulation. Matrix tablets were prepared by wet granulation technique and 5% w/v of AHG dispersion water was used as granulating agent for preparation of AHG matrix tablets. AHD2 (3:20) was found to be the optimized formulation based on in vitro drug dissolution studies. FTIR and DSC studies performed on the optimized formulations indicated no drug-polymer interaction. AHD2 (3:20) was found to be stable after accelerated stability testing for 6 months as per ICH guidelines. Pharmacokinetic studies of the optimized formulation were performed in healthy Albino Wister rabbits in comparison with that of the pure drug by estimating pharmacokinetic parameters and mean residence time (MRT). It was found that there is a significant increase in the bioavailability of diclofenac sodium from AHD2 formulation which was evident from the high AUC and MRT values compared with the pure drug. The above results clearly indicated that AHG gum can be used for the development of oral controlled release dosage forms by using matrix systems.