RELEASE PROFILE OF EXTRACTS OF BRIDELIA FERRUGINEA LEAF AND CANTHIUM GLABRIFLORUM STEM BARK FROM DIFFERENT ABSORBENTS

The aqueous decoctions of Bridelia ferruginea leaf and Canthium glabriflorum stem bark were converted into granules by absorbing into different types of absorbents in different quantities. In vitro dissolution studies were then used to assess the release of the extracts from the granules. Comparative and ranking studies of the effects of different weights of the different absorbents on the release of the extracts by Duncan’s multiple range tests (p=0.05) were used to assess the performance of the absorbents. The λ_max for the extracts were obtained with 0.01 %w/v solutions at 267 nm and 279 nm for B. ferruginea and C. glabriflorum, respectively. The UV absorbances at these frequencies were used as indices for the assay of the active constituents in the respective extracts. The cumulative percentage release of the extracts was generally higher from the extract-absorbent systems than from the pure extracts, for all the different types and weights of absorbents used. The results also indicated significant differences (p = 0.05) in the mean cumulative percent release of both extracts from the different absorbents. There were however, optimised weights of the effective absorbents per dose (weight) of the extracts that produced the best release effects. 76 mg of Microcrystalline cellulose per dose of B. ferruginea extract (155.2 ± 2.0 mg) had the best and most significant release profile (75.3 ± 0.7 %), whilst, 48 mg of bentonite per dose of C. glabriflorum extract (170 ± 2.0 mg), was the most significant with the highest cumulative percent release (99.4 ± 0.2 %) after 45 minutes, indicating their suitability for use in formulating these extracts into solid dosage form.