Determination of the flocculating properties of tapioca when blended
with viscosity enhancing agents: application of tapioca in
pharmaceutical suspensions
Onyekweli, A.O1*, Iwuagwu, M.A.1 and Okore, V.
C.2
1Department
of Pharmaceutics and Pharmaceutical Technology,
Faculty of Pharmacy, University of Benin, Benin City, Nigeria.
2Department
of Pharmaceutics, Faculty of Pharmaceutical Sciences,
University of Nigeria, Nsukka, Nigeria.
ABSTRACT
Studies were carried
out on the influence of tapioca when incorporated into a suspending
medium for pharmaceutical suspensions. Suspensions of sulphadimidine
were separately prepared using pregelatinized starch or sodium
carboxymethylcellulose (SCMC) and their combinations with tapioca,
as suspending agents. The concentrations at which their suspending
abilities were evident were determined and compared (0.5 % w/v for
SCMC or 3.0 % w/v for pregelatinized starch). Combining tapioca (1%
w/v) with either SCMC or pregelatinized starch in concentrations far
below that in which the gel formers demonstrated suspending ability
(0.1 % w/v for SCMC or 1.5 % w/v for pregelatinized starch),
substantially improved both their suspending and flocculating
properties (1.6 times for SCMC and 3.2 times for pregelatinized
starch). This suggests that tapioca, which is a cheap by-product of
cassava processing, may well potentiate the properties of the more
costly, but conventional, suspending agents in the formulation of
acceptable pharmaceutical suspensions. This could have positive
economic implications in the overall production of pharmaceutical
suspensions.
Key words: Tapioca,
pregelatinized starch, sodium CMC, suspending
properties,
flocculating properties, and pharmaceutical suspensions
.
