Delayed-release drug products

These dosage forms include tablets, capsules, solutions, suspensions, conventional/immediate release, and modified (extended, delayed) release drug products. 

As defined in the USP, delayed-release drug products are dosage forms that release the drugs at a time later than immediately after administration (i.e., these drug products exhibit a lag time in quantifiable plasma concentrations). 

Typically, coatings (e.g., enteric coatings) are intended to delay the release of medication until the dosage form has passed through the acidic medium of the stomach. In vivo tests for delayed-release drug products are similar to those for extended-release drug products. In vitro dissolution tests for these products should document that they are stable under acidic conditions and that they release the drug only in a neutral medium (e.g., pH 6.8). 

Modified Release Dosage Forms Dosage forms whose drug-release characteristics of time course and/or location are chosen to accomplish therapeutic or convenience objectives not offered by conventional dosage forms such as a solution or an immediate release dosage form. Modified release solid oral dosage forms include both delayed and extended release drug products. 

Modified Release In this type of release dosage forms include both delayed and extended - release drug products. Delayed release is defined as the release of a drug at a time other than immediately following administration, while extended release products are formulated to make the drug available over an extended period after administration [114]. 

Over the years, dissolution testing has expanded beyond ordinary tablets and capsules—first to extended-release and delayed-release (enteric-coated) articles, then to transder-mals, multivitamin and minerals products, and to Class Monographs for non-prescription drug combinations. (Note at the time, sustained-release products were being tested, unofficially, in the NF Rotating Bottle apparatus). 

Additional criteria for waiver of evidence of in vivo BA/BE are given in 21 CFR 320.22 (d)(3). For certain solid oral dosage forms (other than a delayed or extended-release dosage forms), a waiver for the submission of in vivo evidence of BA/BE is possible if the drug product has been shown to meet the requirements of an in vitro dissolution test, which in turn has been shown to correlate with in vivo data. A biowaiver may also be addressed to a reformulated solid oral dosage form identical to another drug product except for color, flavor, or preservatives for which the same manufacturer has obtained approval, if BA data are available for the approved... 

Fundamental distrust of the industry s ethics. The public realisation that research studies have been withheld from public view, or released in partial (and misleading) form, has created enormous pressures for industry to make information on all trials available via the internet. The delays in relabelling products, the precipitous withdrawal of widely marketed drugs and the failure to identify safety risks before approval (even when it was not scientifically possible to do so) gives support to the canard that companies put profits before people. And prosecutions of major companies for... 

Absorption - /a pro c acid is rapidly and almost completely absorbed from the Gl tract. Absorption of the drug is delayed but not decreased by administration with meals administration of the drug with milk products does not affect the rate or degree of absorption. The bioavailability of valproate from divalproex sodium delayed-release tablets and capsules containing coated particles has been shown to be equivalent to that of valproic acid capsules. 

Enteric Coated Intended to delay the release of the drug (or drugs) until the dosage form has passed through the stomach. Enteric coated products are delayed release dosage forms. 

Delayed release product In appli-cation/compendial release requirements plus dissolution tests in 0.1 N HC1 for 2 hr (acid stage) followed by testing in USP buffer media (pH 4.5-7.5) under application/compendia test conditions and two additional agitation speeds. Application/compen-dial method may be either apparatus 1 or apparatus 2.1 Adequate sampling should be performed (15, 30, 45, 60, and 120 min until either 80% of drug is released or asymptote is reached). Testing should be performed on changed product and biobatch or marketed product. 

Delayed release product Application/compendial release requirements plus multipoint dissolution profile should be obtained during the buffer stage of testing using the application/compendial medium for the changed drug and the biobatch or marketed product. Adequate sampling should be performed (15, 30, 45, 60,... 

Shellac Above pH 7 Original enteric coating material, originally used in sugar-coated tablets high pH required for dissolution may delay drug release natural product which exhibits batch-to-batch variability... 

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