Gastrointestinal bioavailability: Determination of in vivo release profiles of solid oral dosage forms by deconvolution
✍ Scribed by William R. Gillespie; Peter Veng-Pedersen
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 188 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0142-2782
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✦ Synopsis
If a linear relationship exists between the rate of drug release or dissolution in the gastrointestinal tract, f ( t ) , and the resulting systemic drug level, c(t), that relationship can be expressed as a convolution:
where c&) is the systemic drug concentration resulting from the instantaneous introduction of a unit amount of dissolved drug into the GI tract.'.2 In practical terms, c(t) and cb(t) represent the drug concentrations following oral administration of a solid dosage form and an aqueous solution, respectively. If these parameters are known, the in vivo release profile of the solid dosage form may be determined by deconvolution.
This approach is demonstrated using the mean results from a study in which 300 mg of quinidine sulfate (equivalent to 248 mg quinidine base) were administered to 18 subjects as an aqueous oral solution and as a sustained release tablet.' Equations (2) and (3) were fitted to the oral solution and sustained release data, respectively, using the interactive nonlinear regression program, FUNFIT:4 I I c,(t) = D,ch(t) = C a, exp-"t'
(2)