Self-curing controlled release systems for steroids. Application of prednisolone-based polymeric systems to ear diseases.
An injectable delivery system for prednisolone has been prepared based on a self-curing formulation comprised of poly(methyl methacrylate) particles and hydroxyethyl methacrylate as monomer. The polymerisation reaction was initiated by the redox system 4,4'-bis (dimethylaminobenzydrol)/benzoyl peroxide (BZN/BPO) and followed at 25 degrees C by measuring the time-temperature profile. A maximum temperature of 53 degrees C and a setting time of 15 min were obtained, calculated according to standard specifications. The swelling of the cured system was studied in phosphate-buffered saline (PBS) at 37 degrees C giving a hydration degree at equilibrium of 20%. The swelling kinetics fitted a fickian behaviour at the initial stages of the experiments, with a diffusion coefficient of 0.72 x 10(-7) cm2/s. The release of the drug was sustained from the beginning without an initial drug burst. The study of the wettability showed a rather hydrophilic character of the surface of the loaded system, and the biocompatibility evaluated through MTT assay revealed the absence of cytotoxicity due to the release of toxic substances.
Fernandez
Mar
M
Instituto de Ciencia y Tecnología de Polímeros, CSIC, C/Juan de la Cierva, 3, 28006 Madrid, Spain.
Parra
Juan
J
Vazquez
Blanca
B
Lopez-Bravo
Antonio
A
Román
Julio San
JS
D000818:Animals; D001585:Benzoyl Peroxide / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D004396:Coloring Agents / Q000494:pharmacology; D004058:Diffusion; D004337:Drug Carriers; D016503:Drug Delivery Systems; D004427:Ear Diseases / Q000188:drug therapy*; D005938:Glucocorticoids / Q000008:administration & dosage* / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008768:Methylmethacrylates / Q000737:chemistry; D008854:Microscopy, Electron; D008956:Models, Chemical; D010084:Oxidation-Reduction; D011108:Polymers; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011239:Prednisolone / Q000008:administration & dosage* / Q000494:pharmacology; D013256:Steroids / Q000008:administration & dosage*; D013696:Temperature; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors
D001672:Biocompatible Materials; D004396:Coloring Agents; D004337:Drug Carriers; D005938:Glucocorticoids; D008768:Methylmethacrylates; D011108:Polymers; D013256:Steroids; D013778:Tetrazolium Salts; D013844:Thiazoles; D019904:Polymethyl Methacrylate; D011239:Prednisolone; C022616:thiazolyl blue; D001585:Benzoyl Peroxide