Dc. Bibby et al., PREPARATION AND CHARACTERIZATION OF BETA-CYCLODEXTRIN AND POLY(ACRYLIC ACID) MICROSPHERES, Journal of microencapsulation, 15(5), 1998, pp. 629-637
Citations number
8
Categorie Soggetti
Pharmacology & Pharmacy","Chemistry Applied","Engineering, Chemical
A method for the preparation of poly(acrylic acid) (PAA) microspheres
cross-linked with beta-cyclodextrin (beta-CD) is described. The method
is based on a water-in-oil (w/o) emulsion solvent evaporation techniq
ue which facilitates a condensation reaction between PAA and beta-CD.
Aqueous solutions of PAA and beta-CD were used as the dispersed phase
and food grade olive oil was used as the continuous phase. The effect
of homogenization speed (used in the preparation of the emulsion), pha
se volume ratio and cyclodextrin-polymer load on the particle size of
the microspheres produced was investigated in a replicated factorial d
esign. Microspheres were sized by light microscopy. The particle size
of the microspheres was influenced by all three variables with two sig
nificant first order interactions between the variables being observed
(homogenization speed with phase volume ratio and homogenization spee
d with load). A second order interaction between the three principal f
actors was also observed. Particle size ranged from 16 to 150 mu m, de
pending on the production variables employed. The yield for the techni
que was 69.5 +/- 9.5%. Using selected conditions, microspheres of 15-2
5 mu m size were prepared from a range of PAA with different weight av
erage molecular weights (Mw). These particles were then characterized
for beta-CD, free carboxylic acid group content and residual oleic aci
d.