Dissolution Weibull distribution

Although the Noyes-Whitney equation has been used widely, it has been shown to be inadequate in modeling either S-shape experimental data or data with a steeper initial slope. Therefore, a more general function, based on the Weibull distribution [8], was proposed [9] and applied empirically and successfully to all types of dissolution curves [10] ... 

F. Langenbucher. Linearization of dissolution rate curves by the Weibull distribution. J. Pharm. Pharmacol. 

Validation was carried out using the area under the dissolution curve, this being the major response to be optimized. The dissolution curves fitted the Weibull distribution. 

The successful use of the Weibull function in modeling the dissolution profiles raises a plausible query What is the rationale of its success The answer will be sought in the relevance of the Weibull distribution to the kinetics prevailing during the dissolution process. 

Table 2 Wetting dynamic contact angle values of white beeswax coated potassium chloride microcapsules with different core-to-wall ratios and dissolution parameters of the Weibull distribution function (the medium for the wetting and dissolution measurements was distilled water)...

The mean dissolution time (t ) determined by the Weibull distribution function was shortened as the surface tension of the surfactant aqueous solution decreased (Table 3). In accordance with the contact angle decreasing, greater water uptake can be observed, parallel to the drug release rate increasing. 

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