Controlled drug release from poly(ortho esters).
D000812:Anhydrides; D000818:Animals; D001673:Biodegradation, Environmental; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage; D003692:Delayed-Action Preparations; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D007773:Lactates; D019344:Lactic Acid; D016912:Levonorgestrel; D008855:Microscopy, Electron, Scanning; D009644:Norgestrel / Q000008:administration & dosage; D011091:Polyesters / Q000008:administration & dosage* / Q000138:chemical synthesis; D011817:Rabbits
D000812:Anhydrides; D003277:Contraceptives, Oral, Combined; D003692:Delayed-Action Preparations; D007773:Lactates; D011091:Polyesters; D019344:Lactic Acid; D009644:Norgestrel; D016912:Levonorgestrel