EXTRACTION AND PURIFICATION OF STEM BARK GUM OF GREWIA MOLLISJUSS. FOR USE AS A DISINTEGRANT IN TABLET FORMULATION

Abstract

Gums are polysaccharides of natural origin that have been used traditionally as binders in the formulation of tablets
by wet granulation. This research aimed at extraction of Grewia mollis gum (GG) by dispersing 600 g of the dried
and pulverized inner stem bark of the Grewia mollis shrub in about 20 litres of demineralized water using an
impeller, which was further purified by treatment with 0.1 M hydrochloric acid for about 5 minutes followed by
extraction with 25 ml of 95 % Acetone and evaluating the use of bleached acetylated stem bark gum of Grewia
mollis Juss (BAGG) as a disintegrant in tablet formulations using Ibuprofen as a model drug. The yields of the gums
were found to be 58.5, 80.3, and 60.0 % for GG (Grewia Gum), AGM (Acetylated Grewia Gum), and BAGG
(Bleached Acetylated Grewia Gum) respectively. The pH values for the gums were 4.83, 4.95, and 4.01 for GG,
AGM, and BAGG respectively. The swelling capacities were 1.59 ± 0.00, 2.90 ± 0.01, and 2.80 ± 0.00 respectively
for GG, AGM, and BAGG. Moisture contents were 0.54 ± 0.01, 0.13 ± 0.01, and 0.12 ± 0.01 for GG, AGM and
BAGG respectively. The LD 50 values of both the native and derivatized gums were both greater than 5000 mg.
Tablets weighing 500 mg were prepared by compressing ibuprofen granules containing BAGG as disintegrant at
concentrations ranging from 1.25 to 10 % in comparison to maize starch B.P. at the same concentrations. The tablets
formulated were kept for about 24 hours and subsequently evaluated for tablet properties. The outcome of the study
showed that tablets formulated with BAGG - A as disintegrant with a concentration of 1.25 % had an enhanced
disintegration time and dissolution profile comparable to other formulations. Formulation of ibuprofen tablets
containing BAGG - A with 1.25 %, as disintegrant was obtained with the following properties; Crushing strength
(6.9 ± 1.24 kgf), disintegration time (9.47 ± 3.06 min) and friability (0.78 %). The results of this study had been able
to establish that bleached acetylated Gewia mollis stem bark gum, concentration 1.25 %, could be used effectively to
formulate Ibuprofen tablets that disintegrated within 15 mins.