Quantitative determination of release kinetics from fibrous poly(3-hydroxybutyrate) scaffolds

A fibrous scaffold was prepared from poly(3-hudroxybutirate) (PHB) by wet spinning from chloroform solution. The fibers were precipitated into excess ethanol and they had a regular, cylindrical shape. The diameter of the fibers was regulated by the rate of spinning. A model drug, quercetin, was dissolved in the fiber in various amounts. The rate of drug release could be controlled by the adjustment of fiber diameter. A novel approach is proposed in the paper for the quantitative analysis of release kinetics. The model is based on Fick's laws, and does not use any simplification or introduce empirical constants. The prediction of the new model agreed well with experimental results and proved that the approach offers an exact description of experimental data. Although the method allows the estimation of the diffusion coefficient as well, the value obtained is biased because of the large surface to volume ratio of the scaffold. The comparison of the proposed model to empirical or semi-empirical approaches published earlier showed that the latter are less accurate and predict false results at various stages of the release study. The proposed method of fiber preparation and the model makes possible the prediction and control of the release rate of a drug from fibrous scaffolds.