Permeação Passiva de Fármacos - Validação e Implementação de um Ensaio com Lipossomas

The primary goal of this project is to develop a versatile and reproducible membrane-based method for the high-throughput determination of drug passive permeability across biomembranes, and to prepare its implementation as a commercial kit. The liposome pH-variation assay is a particularly suitable basis for this development because its principle applies to any solutes that have ionizable groups, as most drugs do. In order to attain the proposed goal, the following intermediate objectives must be met, which will be addressed in the various tasks of the project. i) The synthesis of novel ratiometric fluorescent pH probes with sensitivity in distinct pH regions, allowing the characterization of permeation of drugs with large diversity of pKa values. Solvent-free synthetic methodologies will be followed to decrease environmental impact. ii) The optimization of the assay with regards to its operational parameters, to increase the sensitivity and robustness of the assay. iii) The formulation of storage-stable vesicle preparations with defined membrane compositions and from membranes obtained from cell lines representative of pharmacologically-relevant physiological barriers. iv) The development of a user-friendly software application to allow the simple and accurate analysis of the assay results by non-expert users. v) The intra- and inter-laboratory validation of the assay kits, preparing for its future commercialization. vi) The use of the assay to characterize the permeation properties of a large number of bioactive acids and bases, covering a wide range of the chemical space. The pursuit of this last objective will generate a large amount of high-quality data that will be invaluable for improving the predictability of the passive permeability of drugs and bioactive small molecules through biomembranes. The project will not miss out on this scientific opportunity. Therefore, a task will be devoted to the rationalization of the permeability coefficients, seeking to establish quantitative relations with molecular structure and lipid membrane properties. This will be achieved through complementary experiments, molecular dynamics simulations and kinetic modelling of the permeation process. These studies will likely further highlight that the permeability of many drugs depends on factors that the liposome-based assay from this project can capture but classical permeation assays cannot, which will promote the future wide adoption of the kits. In turn, several additional indirect goals are aligned with the UN 2030 agenda, as well as both national and regional guidelines. These indirect goals, which will naturally result from achievement of the above objectives, include advanced training of young people for highly skilled work, technological and economic growth for the regional and national pharmaceutical industry, and, most importantly, establishment of improved means for drug development worldwide and improved predictive power at the level of drug design, with huge concomitant gains in the economy and population well-being. To timely accomplish all the objectives above we assembled a cohesive team that has all the necessary skills and a history of successful collaborative accomplishments in the road towards the proposed goals. This team is complemented by three reputed international consultants who will collaborate in experimental design, data analysis and inter-laboratory validation of the kits.