Effect of particle size on thein vitro andin vivo degradation rates of poly(DL-lactide-co-glycolide) microcapsules

✍ Scribed by Visscher, G. E. ;Pearson, J. E. ;Fong, J. W. ;Argentieri, G. J. ;Robison, R. L. ;Maulding, H. V.

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 1000 KB
• Volume: 22
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820220806

✦ Synopsis

New fersey 07936

Three different sieve size fractions of ergotcontaining biodegradable microcapsules were examined both in uitro and in vivo.

The sieve sizes and average particle diameter, (pm), w e r e i l c s s than 45-75 (x = 30); 75-106 ( X = 79); 106-177 (x = 130). These microcapsules contained ca. 9% drug and were produced from 50: 50 poly(DL-lactide-co-glycolide). The objective was to determine the effect of particle size on in uiuo and in vitro degradation rates. The microcapsules were injected into rat gastrocnemius muscle and excised and examined at various time points up to 70 days. Initially a minimal tissue response was noted which was characterized by a sharply localized acute inflammatory reaction. Following this, connective tissue and foreign body giant cells engulfed the microcapsules at 20-30 days. Only vestiges of the microcapsules were found surrounded by minimal connective tissue and foreign body giant cells after 60-70 days. The tis- sue reaction was a minimal, sharply localized foreign body giant cell and connective tissue process for all three size groups of njcrocapsules. The largest microcapsules ( X = 130 pm) exhibited a slightly greater tendency to undergo in vivo and in vifro degradation relative to the other groups. However, it can be concluded that over the microcapsule size ranges examined minimal differences in the degradation properties of the polymeric matrices and consequently those of the microcapsules were noted.