PREPARATION AND CHARACTERIZATION OF BETA-CYCLODEXTRIN AND POLY(ACRYLIC ACID) MICROSPHERES

Citation
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
ISSN journal
02652048
Volume
15
Issue
5
Year of publication
1998
Pages
629 - 637
Database
ISI
SICI code
0265-2048(1998)15:5<629:PACOBA>2.0.ZU;2-X
Abstract
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.