缓释、控释和迟释制剂指导原则(2010版药典附录)（Guidelines for sustained release, controlled release and delayed release (2010 edition, appendix)）.docVIP

缓释、控释和迟释制剂指导原则(2010版药典附录)（Guidelines for sustained release, controlled release and delayed release (2010 edition, appendix)） Principles of sustained release, controlled release and delayed release Compared with the common preparations, the sustained release controlled release preparations have long lasting effects, low toxic side effects and fewer times of drug use. Due to the design requirements, drugs can be slowly released into the body, the blood concentration of quotpeak valleyquot is small, can avoid over treatment of blood drug concentration range of side effects, and can keep the effective concentration range (therapeutic window) within in order to maintain curative effect. Controlled release formulations also include eye, nose, ear, vagina, anus, oral or dental, transdermal or subcutaneous, intramuscular and subcutaneous implantation, slow the release of the drug absorption, preparation portal system to avoid the first pass effect. Delayed release preparation means after the administration does not immediately release drugs, such as avoiding drug inactivation or the stimulation of the stomach in the stomach, and delayed enteral preparations to release or release in the colon, including pulse preparation suddenly released under certain conditions. The principle of release of controlled release, controlled release and delayed release preparations is mainly controlled by dissolution, diffusion, dissolution, diffusion and dissolution, and also by osmotic pressure or ion exchange mechanism. The release process can be fitted by different equations, such as first order equation, Higuchi equation, zero order equation, etc. (except pulse preparation). The main difference between the sustained and controlled release of sustained-release preparation is according to the time variation of the first after more than a few non constant speed release, and controlled release preparation is released according to the zero order rate law, namely, the drug release was not influe