[en] Attention has been paid to phase separation of poly (lactide-co-glycolide) solutions in CH2Cl2 induced by the addition of a silicone oil in order to promote protein microencapsulation. Since the process is very fast, the system is anytime out of equilibrium. The effect of the main processing parameters on the microencapsulation process has been analyzed and has highlighted that kinetics of the main encapsulation steps has a great effect on the characteristics of the final microspheres. These results have been discussed on the basis of a physico-chemical study of coacervation reported in previous papers of this series.
Research center :
Center for Education and Research on Macromolecules (CERM)
Nihant, N.; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Grandfils, Christian ; Université de Liège - ULiège > Département des sciences biomédicales et précliniques > Biochimie et physiologie générales, et biochimie humaine
Jérôme, Robert ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Teyssié, Philippe ; Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Language :
English
Title :
Microencapsulation by coacervation of poly(lactide-co-glycolide). IV. Effect of the processing parameters on coacervation and encapsulation
Lyman, Rowland (1985) Biomaterials. Encyclopedia of Polymer Science and Engineering, Anionic Polymerization to Cationic Polymerization , Wiley-Interscience, New York; 267-286.
Vert (1986) Biomedical polymers from chiral lactides and functional lactones Properties and application. Makromolekulare Chemie. Macromolecular Symposia , 2nd edn.; 6:109-122.
Remboum, Shen Biomedical Polymers, Marcel Dekker, New York; 1971.
Buri, Puisieux, Doelker, Benoit (1985) Formes Pharmaceutiques Nouvelles: Aspects Technologiques. Biopharmaceutiques, et Médicaux, 2nd edn., Lavoisier Tec and Doc, Paris; .
Robinson, Lee (1987) Controlled Drug Delivery. Fundamentals and Applications, 2nd edn., Marcel Dekker, New York; .
Langer (1991) Polymer implants for drug delivery in the brain. J. Control. Release 16:53-60.
Dubois, Jacobs, Jérôme, Teyssié (1991) Macromolecular engineering of polylactones and polylactides, 4. Mechanism and kinetics of lactide homopolymerization by aluminum isopropoxide. Macromolecules 24:2266-2270.
Dubois, Jérôme, Teyssié (1991) Aluminium alkoxides A family of versatile initiators for the ring-opening polymerization of lactones and lactides. Makromolekulare Chemie. Macromolecular Symposia 42:103-116.
Doelker, Buri (1975) Une technique récente en pharmacie galénique, le micro-encapsulage. Pharm. Acta Helv. 50:73-87.
Nihant, Schugens, Grandfils, Jérôme, Teyssié (1994) Polylactide microspheres prepared by double emulsion/ evaporation technique. I. Effect of the primary emulsion stability. Pharm. Res. 11:1479-1484.
Schugens, Laruelle, Nihant, Grandfils, Jérôme, Teyssié (1994) Polylactide microparticles prepared by double emulsion-evaporation. III. Effect of the primary and secondary emulsions. J. Control. Release 32:161-176.
Ogawa, Yamamoto, Takada, Okada, Shimamoto (1988) Controlled-release of leuprolide acetate from polylactic acid or copoly(lactic/glycolic) acid microcapsules: influence of molecular weight and copolymer ratio of polymer. Chem. Pharm. Bull. 36:1502-1507.
Ruiz, Tissier, Benoit (1989) Microencapsulation of peptide: a study of the phase separation of poly(D,L-lactic acid-co-glycolic acid) copolymer 50/50 by silicone oil. Int. J. Pharm. 49:69-77.
Ruiz, Benoît (1991) In vivo peptide release from poly(DL-lactic acid-co-glycolic acid) copolymer 50/50 microspheres. J. Control. Release 16:177-186.
Lapka, Masson, Thies Process for preparation of microcapsules, U.S. Patent, 4,622,244; 1986.
Stassen, Nihant, Martin, Grandfils, Jérôme, Teyssié (1994) Microencapsulation by coacervation of poly (lactide-co-glycolide). I Physico-chemical characteristics of the phase separation process. Polymer 35:777-785.
Nihant, Stassen, Grandfils, Jérôme, Teyssié (1993) Microencapsulation by coacervation of poly(lactide-co-glycolide). II Encapsulation of a dispersed aqueous phase. Polym. Int. 32:171-176.
Nihant, Stassen, Grandfils, Jéröme, Teyssié, Goffinet (1994) Microencapsulation by coacervation of poly(lactide-co-glycolide) III. Characterization of the final microspheres. Polym. Int. 34:289-299.
Torza, Mason (1970) Three-phase interactions in shear and electrical fields. J. Colloid Interface Sci. 33:67-83.
Grandfils, Flandroy, Nihant, Barbette, Jérôme, Teyssié (1992) Preparation of poly (D,L)lactide microspheres and their clinical applications as a convenient embolic material. J. Biomed. Mater. Res. 26:467-479.
Benita, Benoit, Puisieux, Thies (1984) Characterization of drug-loaded poly(d,l-lactide) microspheres. J. Pharm. Sci. 73(12):1721-1724.
Iso, Kando, Omi (1985) A fundamental study of the microencapsulation procedure utilizing coacervation in a polystyrene-cyclohexane solution. J. Microencapsulation 2:275-287.
Heinrich, Wolf (1990) Kinetics of phase separation: trapping of molecules in nonequilibrium phases. Macromolecules 23:590-596.
Graham, Phillips (1979) Proteins at liquid interfaces. I. Kinetics of adsorption and surface denaturation. J. Colloid Interface Sci. 70:403-414.
Donbrown, Benita, Hoffman (1983) Microencapsulation of dichromate and paracetamol with Eudragit Retard polymers using phase separation by non-solvent addition. 5th International Symposium on Microencapsulation including Artificial Cells , Montreal, Appl. Biochem. Biotechnol.; 10:245-249.
