Drug Release Dosage Forms
Controlled release (CR) is also known in the industry as extended release (ER), modified release (MR), or timed release. GastroPlus® includes the ability to simulate the controlled release (CR) of drug material. The Controlled Release dosage form allows release of either dissolved material (drug in solution) or undissolved material (solid particles), which then dissolves according to the Dissolution model, allowing the simulation of controlled release technologies that release material in either form. With the Controlled Release dosage form, you can control the percent released versus time with entries in an interpolated series, or by setting the parameters of a single, double, or triple Weibull function. For tabulated % released vs. time data, GastroPlus® performs linear interpretation between the data points. Controlled Release dosage forms include Dispersed, Integral Tablet, and Gastric Release. Delayed Release dosage forms include enteric-coated particles in a capsule and enteric-coated tablets.
Controlled Release dosage
The Dispersed dosage form allows unreleased drug to follow the same dispersion model used for undissolved and dissolved drug, where the transit rate of drug in any compartment is determined by a transfer rate constant, kt, which is based on the mean transit time for the compartment.
The Integral Tablet dosage form keeps all remaining unreleased drug together, allowing it to transit to the next compartment at the end of the mean transit time of the current compartment.
The Gastric Release dosage form retains all unreleased material in the stomach compartment for a user-specified period of time, so that only drug that has been released can transit into the duodenum.
Delayed Release dosage
The Enteric-Coated Capsule dosage form distributes the particles throughout the GI tract. The particles leave the stomach immediately at a rate calculated as “1/transit time.” Only those particles that leave the stomach dissolve, where the dissolution is carried out as for the Integral Tablet dosage form.
The Enteric-Coated Tablet dosage form retains the whole tablet in the stomach for the period of the stomach transit time. After the tablet leaves the stomach, the dissolution is carried out as for the Integral Tablet dosage form.