Controlled release
Encyclopedia
Controlled release is a term referring to the presentation or delivery of compounds in response to stimuli or time. This can be for purposes in several areas including agriculture, cosmetics and personal care, pharmaceuticals and food science. Most commonly it refers to time dependent release in oral dose formulations. Timed release has several distinct variants such as
sustained release
where prolonged release is intended, pulse release, delayed release (e.g. to target different regions of the GI tract) etc. A distinction of controlled release is that not only prolongs action but it attempts to maintain drug levels within the therapeutic window
to avoid potentially hazardous peaks in drug concentration following ingestion or injection and to maximize therapeutic efficiency.
The science of controlled release originates from the development of oral sustained-release products in the late 1940s and early 1950s, the development of controlled release of marine anti-foulants in the 1950s and controlled release fertilizer in the 1970's where sustained and controlled delivery of nutrients following a single application to the soil. Delivery is usually effected by dissolution, degradation or disintegration of an excipient
in which the active compound is formulated. Enteric coating
and other encapsulation technologies can further modify release profiles.
In addition to pills, capsules and injectable drug carriers (that often have an additional release function), forms of controlled release medicines include gels , implants and devices (e.g. the Vaginal ring
and contraceptive implant
) and transdermal patches.
Examples of stimuli that may be used to bring about release include pH, enzymes, light, magnetic fields, temperature, ultrasonics, osmosis and more recently electronic control of MEMS and NEMS
.
Examples of cosmetics, personal care and food science applications often centre on odour or flavour release.
The release technology scientific and industrial community is represented by the Controlled Release Society (CRS). The CRS is the worldwide society for delivery science and technologies. CRS serves more than 1,600 members from more than 50 countries. Two-thirds of CRS membership is represented by industry and one-third represents academia and government. CRS is affiliated with the Journal of Controlled Release
and Drug Delivery and Translational Research scientific journals.
sustained release
Sustained release
Time release technology, also known as sustained-release , sustained-action , extended-release , time-release or timed-release, controlled-release , modified release , or continuous-release , is a mechanism used in pill tablets or capsules to...
where prolonged release is intended, pulse release, delayed release (e.g. to target different regions of the GI tract) etc. A distinction of controlled release is that not only prolongs action but it attempts to maintain drug levels within the therapeutic window
Therapeutic window
The Therapeutic window of a drug is the range of drug dosages which can treat disease effectively while staying within the safety range. In other words, it is the dosages of a medication between the amount that gives an effect and the amount that gives more adverse effects than desired effects...
to avoid potentially hazardous peaks in drug concentration following ingestion or injection and to maximize therapeutic efficiency.
The science of controlled release originates from the development of oral sustained-release products in the late 1940s and early 1950s, the development of controlled release of marine anti-foulants in the 1950s and controlled release fertilizer in the 1970's where sustained and controlled delivery of nutrients following a single application to the soil. Delivery is usually effected by dissolution, degradation or disintegration of an excipient
Excipient
An excipient is generally a pharmacologically inactive substance used as a carrier for the active ingredients of a medication. In many cases, an "active" substance may not be easily administered and absorbed by the human body; in such cases the substance in question may be dissolved into or...
in which the active compound is formulated. Enteric coating
Enteric coating
An enteric coating is a barrier applied to oral medication that controls the location in the digestive system, where it is absorbed. Enteric refers to the small intestine, therefore enteric coatings prevent release of medication before it reaches the small intestine.Most enteric coatings work by...
and other encapsulation technologies can further modify release profiles.
In addition to pills, capsules and injectable drug carriers (that often have an additional release function), forms of controlled release medicines include gels , implants and devices (e.g. the Vaginal ring
Vaginal ring
Vaginal rings are polymeric drug delivery devices designed to provide controlled release of drugs for intravaginal administration over extended periods of time. The ring is inserted into the vagina and provides contraception protection...
and contraceptive implant
Contraceptive implant
A contraceptive implant is a birth control device inserted under the skin. Brands include:*Norplant and Jadelle *Implanon*Sino-implant marketed as Zarin, Femplant and Trust*Nexplanon Implanon replacement...
) and transdermal patches.
Examples of stimuli that may be used to bring about release include pH, enzymes, light, magnetic fields, temperature, ultrasonics, osmosis and more recently electronic control of MEMS and NEMS
NEMS
NEMS may refer to;* Nanoelectromechanical systems* National Energy Modeling System* Nems * NEMS Enterprises , based in Argentina...
.
Examples of cosmetics, personal care and food science applications often centre on odour or flavour release.
The release technology scientific and industrial community is represented by the Controlled Release Society (CRS). The CRS is the worldwide society for delivery science and technologies. CRS serves more than 1,600 members from more than 50 countries. Two-thirds of CRS membership is represented by industry and one-third represents academia and government. CRS is affiliated with the Journal of Controlled Release
Journal of Controlled Release
The Journal of Controlled Release is a bimonthly peer-reviewed medical journal and the official journal of the Controlled Release Society. The journal contains papers detailing research involving the controlled release and delivery of drugs and other biologically active agents...
and Drug Delivery and Translational Research scientific journals.