Purified Cashew Gum as an Effective Natural Tablet Binding Agent

Abstract

Purpose: Cashew tree Anacardium occidentale is a spreading ever green perennial tree. The plant is naturalized and cultivated in the warmer parts of Sri Lanka. This study focused on evaluating purified cashew gum as an effective binding agent in tablet formulation using a range of binder solution strengths and different tablet formulations. A difficult to formulate "all starches filler tablet" was attempted as a challenge for the binding strength of the purified cashew gum. Method: Crude cashew gum was collected from the main trunk and purified by dialysis. The aqueous solution containing higher molecular mass fraction obtained from dialysis was then lyophilized. Placebo, pyridoxine hydrochloride 2 mg and carbamazepine 100 mg tablets were prepared using the high molecular mass fraction known as purified cashew gum. The physico-chemical properties of the purified gum were investigated. Physical properties of the tablets prepared with four binders, purified cashew gum, gum xanthan, hydroxypropyl methylcellulose and maize starch were studied and compared with respect to diameter, thickness, hardness, friability, weight variation and disintegration time. Results: The purified cashew gum was of a light amber color, glistening pieces and was odorless. It was found that the gum resembles the properties of gum acacia with parameters well within those of British Pharmacopeia specifications. A unique all starches filler tablets were a success. Tablets prepared with all four binders exhibited similar physical properties. Conclusion: It was possible to purify the gum to a specified quality similar to that of gum acacia. Tablets made with the cashew gum met the tested British Pharmacopeia specifications similar to the conventional binders indicating the potential for the use of purified cashew gum as a pharmaceutical binding agent.