Abstract
The pharmacokinetic and pharmacodynamic effects of along-acting formulation of levonorgestrel microencapsulated in a biodegradable polymer poly(dl-lactide-co-glycolide) was tested in baboons. The polymer microspheres provided continuous release of levonorgestrel for up to 6 months following a single intramuscular injection. The treatment inhibits ovarian function for 3–6 months, depending on the dose. The duration and pattern of levonorgestrel release varies according to the quality and size of the microspheres. The microsphere delivery system offers a promising new approach to developing a long-acting injectable contraceptive based on levonorgestrel.
Resumé
Les effects pharmacocinétiques et pharmacodynamiques d'une formule de lévonorgestrel à longue durée d'action microencapsulée dans un polymère biodégradable (polylactide-coglycolyde) ont été testés sur des baboins. Les microsphères de polymère assurent une libération continue de lévonorgestrel pendant une durée allant jusqu'à 6 mois après une injection intramusculaire unique. Le traitement inhibe la fonction ovarienne pendant 3 à 6 mois, suivant la dose. La durée et l'évolution de la libération du lévonorgestrel varient avec la qualité et la taille des microsphères. Le système de libération par microsphères constitue une approche nouvelle et prometteuse de la mise au point d'un contraceptif injectable à longue durée d'action à base de lévonorgestrel.
Resumen
Los efectos farmacokinéticos y farmacodinámicos de un compuesto de acción prolongada de levonorgestrel microencapsulado en un polímero biodegradable (polilactideco-glicolido) fueron ensayados en babuinas. Las microesferas polímeras proporcionaron una liberación continua de levonorgestrel hasta 6 meses después de una sola inyección intramuscular. El tratamiento inhibe la función ovárica de 3 a 6 meses según la dosis. La duración y forma de liberación de levonorgestrel varía de acuerdo con la calidad y tamaño de las microesferas. El sistema de liberación por microesferas ofrece un prometedor nuevo enfoque hacia el desarrollo de un contraceptivo inyectable de acción larga basado en levonorgestrel.
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Beck, L.R., Pope, V.Z., Tice, T.R. et al. Long-acting injectable microsphere formulation for the parenteral administration of levonorgestrel. Adv Contracept 1, 119–129 (1985). https://doi.org/10.1007/BF01849793
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DOI: https://doi.org/10.1007/BF01849793