Most of the new active pharmaceutical ingredients (API) are poorly soluble in water, leading to the development of new, more complex delivery systems such as amorphous solid dispersions (ASD). Due to the complexity of the processes that take place during release and absorption of API, in some cases with the classical dissolution methods it is not possible to satisfactorily describe all the processes that affect them. Consequently, the development of methods that simulate the conditions of the digestive tract in vivo is necessary (so-called biorelevant methods). The subject of the master's thesis was ASD, prepared by extrusion from poorly soluble active pharmaceutical ingredient BCS II class and polymer. In this paper, we studied the influence of process temperature and speed of rotation of the extruder during extrudate preparation and the ratio between API and polymer on the kinetics of API release from differently prepared ASD. Dissolution tests were performed in various biorelevant media (0.3% SLS in water, FaSSIF pH 6.5 and FaSSIF pH 5.8) on a USP2 device. The main purpose was to develop a ASD, which would assure the same relese kinetics as reference product under biorelevant conditions. To check compliance with the specification limits, we performed experiments according to the QC ("Quality control") method, which consists of an acidic and a neutral phase. We also tried to develop more biorelevant methods for the active substance (biphasic method and MicroFLUX method). With the help of the listed media and methods, we showed that the extruson process parameters (melt extrusion temperature and speed of rotation) affect the API release from the final formulation. In the medium with 0.3 % SLS in water, higher release profiles were observed in the case of all formulations with a higher API content in the extrudate than in the case of formulations with a lower API content. In both FaSSIF media, on the other hand, formulations with a higher API content in the extrudate had higher release profiles in case they were prepared at a higher extrusion temperature and higher speed of rotation in the extruder. In the case of formulations with a lower API content, only the effect of the speed of rotation was observed on the release profiles. Based on the available in vivo data from the performed bioequivalence studies, we estimated that the MicroFLUX method proved to be the most biorelevant method. SLS and FaSSIF results are not equivalent and that each is sensitive to other critical parameters. Based on our experiments, we concluded that it makes sense to use a combination of the described methods to guide the development of a bioequivalent product.
|