Purpose: To investigate the
effectiveness of three natural gums, namely albizia,
cissus and khaya gums, as excipients for the formulation
of ibuprofen microbeads.
Methods: Ibuprofen microbeads were
prepared by the ionotropic gelation method using the
natural gums and their blends with sodium alginate at
various concentrations using different chelating agents
(calcium chloride, zinc chloride, calcium acetate and
zinc acetate) at different concentrations. Microbeads
were assessed using SEM, swelling characteristics, drug
entrapment efficiencies, release properties and drug
release kinetics.
Results: The natural gums alone
could not form stable microbeads in the different
chelating agents. Stable small spherical discrete
microbeads with particle size of 1.35 ± 0.11 to 1.78 ±
0.11 mm, were obtained using the blends of natural gum:
alginate at total polymer concentration of 2 % w/v using
10 % w/v calcium chloride solution at a stirring speed
of 300 rpm. The encapsulation efficiencies of the
microbeads ranged from 35.3 to 79.8 % and dissolution
times, t15 and t80 increased with
increase in the concentration of the natural gums
present in the blends. Controlled release was obtained
for over 4 h and the release was found to be by a
combination of diffusion and erosion mechanisms from
spherical formulations.
Conclusion: The three natural gums
would be useful in the formulation of ibuprofen
microbeads and the type and concentration of natural gum
in the polymer blend can be used to modulate the release
properties of the microbeads.
Keywords: Microbeads, Ibuprofen,
Natural gums, Sodium alginate, Drug release kinetics