A extended release coating consists of both sustained-release and controlled-release coatings. This is used to control the release location of the active ingredient and the predetermined rate of release.
Extended release products are usually coated tablets or capsules designed to pass through the stomach unaltered, which then later release their medication within the intestinal tract. They are designed to release their medication in a controlled manner, at predetermined rate, duration and location to achieve and maintain optimum therapeutic blood levels of the chosen drug containing beadlet technology.
Most commonly, extended release capsules and tablets are taken only once or twice a day to reduce the amount the consumer must swallow to avoid inconvenience. Other conventional forms may have to be taken between three and four times daily to achieve the same therapeutic effect.
Typically, extended release products provide an immediate release of medication that promptly produces the desired therapeutic effect, followed by a gradual release of additional amounts of drug to maintain this effect over a predetermined period.
The advantages of an extended release product include a reduction in drug blood level fluctuations. By controlling the rate of drug release, rapid increase
and decrease of blood levels are eliminated and more side effects are removed. The reduction in frequency of dosage is halved and with less frequency of dose administration, a patient is less likely to neglect specific dosage.
Although the initial cost of extended release dosage forms may be greater than that for conventional dosage forms, the overall cost of treatment may be less due to the therapeutic benefits, overall cost of a full treatment, fewer side effects and a reduction in the time some pharmaceutical personnel need to dispense and administer drugs and monitor patients in hospitals and caring homes.
Coated beads or microspheres can be included within the extended release capsule by placing the microspheres within a tablet or capsule. Using conventional pan coating, a solution of the drug substance is placed onto small microcrystalline cellulose spheres. These spheres are then placed within the tablet or capsule, modifying drug dissolution by controlling the access of biological fluids to the drug using a barrier coating.