RESUMEN
The Food and Drug Administration (FDA) is reclassifying tricalcium phosphate (TCP) granules for dental bone repair from class III to class II (special controls), classifying into class II (special controls) other bone grafting material for dental indications, and revising the classification name and identification of the device type. Bone grafting materials that contain a drug that is a therapeutic biologic will remain in class III and continue to require a premarket approval application. The classification identification includes materials such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen. This action is being taken to establish sufficient regulatory controls that will provide reasonable assurance of the safety and effectiveness of these devices. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for the class II devices.
Asunto(s)
Sustitutos de Huesos/clasificación , Fosfatos de Calcio/clasificación , Materiales Dentales/clasificación , Trasplante Óseo , Colágeno/clasificación , Durapatita/clasificación , Seguridad de Equipos/clasificación , Humanos , Ácido Láctico/clasificación , Ácido Poliglicólico/clasificación , Polímeros/clasificación , Estados Unidos , United States Food and Drug AdministrationRESUMEN
Poly(DL-lactide-co-glycolide) (PDLLGA) and poly(L-lactide-co-glycolide) (PLLGA) copolymers were prepared by bulk ring opening polymerization of lactide and glycolide and characterized by GPC, FTIR, 1H NMR and DSC. Copolymers with different molar masses at a constant lactide/glycolide ratio were used for preparation of bovine serum albumin (BSA)-loaded microparticles by the double emulsion w/o/w method. The influence of the copolymer molar mass and composition on the microparticle morphology, size, yield, degradation rate, BSA-loading efficiency and BSA release profile were studied. For microparticles prepared from PDLLGA copolymers, a biphasic profile for BSA release was found and for those made from PLLGA copolymers the release profile was typically triphasic; both of them were characterized by high initial burst release. Possible reasons for such behavior are discussed.
Asunto(s)
Preparaciones de Acción Retardada/síntesis química , Preparaciones de Acción Retardada/farmacocinética , Ácido Láctico/síntesis química , Ácido Láctico/farmacocinética , Tamaño de la Partícula , Ácido Poliglicólico/síntesis química , Ácido Poliglicólico/farmacocinética , Polímeros/síntesis química , Polímeros/farmacocinética , Animales , Bovinos , Química Farmacéutica/métodos , Portadores de Fármacos/síntesis química , Portadores de Fármacos/farmacocinética , Emulsiones , Glicolatos/síntesis química , Glicolatos/farmacocinética , Ácido Láctico/clasificación , Ácido Poliglicólico/clasificación , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros/clasificación , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/farmacocinética , Tecnología Farmacéutica/métodosRESUMEN
Microspheres for the controlled release of an antisense oligonucleotide against the Transforming growth factor beta(1) were designed. Free oligonucleotide or its solid complexes with polyethylenimine (PEI) at different nitrogen/phosphate (N/P) ratios, were encapsulated within poly(lactide-co-glycolide) (PLGA) microspheres prepared by the multiple emulsion-solvent evaporation technique. The encapsulation of the oligonucleotide in form of solid complexes, the N/P ratio, as well as the PLGA type affected microspheres characteristics in term of loading, morphology, oligonucleotide distribution inside matrix and in vitro release profile. The designed microspheres allow the encapsulation and slow release of oligonucleotide/PEI solid complexes that should be effectively internalized inside cells.