Foto del docente

Roberto Gotti

Associate Professor

Department of Pharmacy and Biotechnology

Academic discipline: CHIM/08 Pharmaceutical Chemistry


Keywords: chiral separation validation of analytical methods capillary electrophoresis chromatographic analysis sample preparation

The research area is in the field of pharmaceutical analysis and in particular it concerns the development and application of chromatographic techniques (HPLC and GC-MS) and capillary electrophoresis (CE) in analysis of bioactive compounds.

The specific subjects of research are:
1) Development and application of electrokinetic systems based on complex pseudostationary phases (mixed micelle, micelle-cyclodextrin, microemulsions, proteins).
2) Development and application of chromatographic methods in analysis of bioactive compounds in complex samples.
3) Development and application of affinity capillary electrophoretic methods in binding study drugs-proteins. 

1. Development and application of electrokinetic systems based on complex pseudostationary phases.
Improved separation selectivity in electrokinetic systems can be achieved by supplementing the electrophoretic running buffer with additives able to establish reversible interactions with the solutes to be separated. Among the additives, surfactants are very successful; they are used at concentration higher the critical micelle concentration (cmc). Under these condition a micellar pseudostationary phase is obtained. In this field the research activity has been addressed to the development of new micellar systems based on mixed micelle (from different surfactants) such as sodium dodecyl sulfate (SDS) and bile salts. Further, the role of cyclodextrins as chiral additives in electrokinetic systems has been considered. Finally, microemulsion based on oils such as heptane and octane in the presence of surfactants and co-surfactants, have been applied as separation pseudostationary phases. The possible role of the components of the considered pseudostationaty phases can be hypothesized by means of the evaluation of characteristic chromatographic parameters such as selectivity, resolution, capacity factor, and efficiency; furthermore, also physico-chemical parameters such as zeta potential, ionic radius of the micelle aggregates, inclusion/complexation constants and kinetic constants can be determinated in order to characterize the complex systems.
The use of proteins as additives to the running buffer belongs to this research field; proteins can be considered as useful chiral selectors.
In general the development of all of these described complex systems can be advantageously carried out by means of chemometric and Quality by Design approaches: this part of the research activity is in collaboration with a team of the University of Florence. The proposed CE systems allowed to achieve interesting and useful methods for related substances analysis in pharmaceuticals.
2. Development and application of chromatographic methods (HPLC, GC-MS, CE and CE-MS) in analysis of drugs and biomoelcules (including metabolites) in complex real samples.
The development, validation and application of chromatographic methods in pharmaceutical analysis is a field of the present research. Sensitive, reproducible and accurate determination of the active components require for efficient analytical techniques such as GC-MS, HPLC-MS and CE, also used in integrated approaches and in combination with sample prep methods as solid phase microextraction (SPME). In addition a new approach to the hyphenation CE-MS is developing for the direct insertion of the CE effluent to the electron impact (EI) source.
3. Affinity capillary electrophoresis
Affinity capillary electrophoresis (ACE) allows for the estimation of binding parameters related to the weak interactions between drugs and proteins.