caa a22 4500 477128416 CHVBK 20180405111656.0 cr unu---uuuuu 170330e19971101xx s 000 0 eng 10.1023/A:1012122200381 doi (NATIONALLICENCE)springer-10.1023/A:1012122200381 Biological Activity of Lysozyme After Entrapment in Poly (d,l-lactide-co-glycolide)-Microspheres [Elektronische Daten] [Raouf Ghaderi, Johan Carlfors] Purpose. The purpose of this study was to investigate the process of preparing microspheres for maximising entrapment efficiency (EE) and retained biological activity (RBA) of peptides and proteins. Methods. A controlled-release formulation based on poly(d,l-lactide-co-glycolide) was designed and produced using a small-scale double emulsion method. These PLG microspheres contained a model peptide, lysozyme. The retained bioactivity of the incorporated lysozyme was determined by bacterial assay. The size distributions and the morphology of the microspheres were characterized. Results. The RBA and EE improved when the PLG concentration in the organic phase of the emulsion was increased. A high lysozyme concentration in the inner water phase of the emulsion resulted in decreased EE and an increase in the proportion of fragmented particles. The RBA of lysozyme in the microspheres varied between 30 and 80% with changes to the process. Conclusions. The study shows that the RBA of lysozyme in PLG microspheres is strongly dependent on the experimental conditions for preparing the microspheres. Measurement of the EE alone, without the RBA is insufficient to evaluate the efficacy of the designed delivery system. Plenum Publishing Corporation, 1997 poly (d,l-lactide-co-glycolide) nationallicence biodegradable microspheres nationallicence lysozyme nationallicence entrapment nationallicence enzyme nationallicence activity nationallicence Ghaderi Raouf Department of Pharmaceutics, Uppsala University, P. O. Box 580, S-751 23, Uppsala, Sweden aut Carlfors Johan Department of Pharmaceutics, Uppsala University, P. O. Box 580, S-751 23, Uppsala, Sweden aut Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/11(1997-11-01), 1556-1562 0724-8741 14:11<1556 1997 14 11095 https://doi.org/10.1023/A:1012122200381 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012122200381 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ghaderi Raouf Department of Pharmaceutics, Uppsala University, P. O. Box 580, S-751 23, Uppsala, Sweden aut NATIONALLICENCE 700 1- Carlfors Johan Department of Pharmaceutics, Uppsala University, P. O. Box 580, S-751 23, Uppsala, Sweden aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/11(1997-11-01), 1556-1562 0724-8741 14:11<1556 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer