|Tipo di tesi||Tesi di laurea magistrale|
|Titolo||Ottimizzazione dei processi di microincapsulazione mediante il design of experiments: applicazione alla reazione di transacilazione in emulsione|
|Titolo in inglese||Optimization of microencapsulation processes through design of experiments: application to transacylation in emulsion|
|Struttura||Dipartimento di Scienze della Vita|
|Corso di studi||CHIMICA E TECNOLOGIA FARMACEUTICHE (D.M. 270/04)|
|Data inizio appello||2020-10-29|
|Disponibilità||Accessibile via web (tutti i file della tesi sono accessibili)|
Lo scopo di questo studio è ottimizzare un metodo di microincapsulazione attraverso un approccio statistico chiamato design of experiments (DOE). Il metodo scelto per produrre microcapsule è la reazione di transacilazione che avviene in emulsione acqua/olio fra propilene glicole alginato (PGA) e albumina sierica umana (HSA).
The aim of this study is to optimize a microencapsulation method using a transacylation reaction in emulsion to produce microcapsules made of covalently linked propylene glycol alginate (PGA) and human serum albumin (HSA). This technique involves the formation of an amide bond between the free amine function of HSA and the ester group of PGA in an w/o emulsion after alkalinization. In the end we obtained biocompatible, stable and biodegradable microcapsules that are potentially used for drug delivery in different fields such pharmaceutical or cosmetic. The standard procedure established for the transacylation reaction between PGA and HSA is the following: first, the aqueous solution is prepared dissolving 0,3 g of PGA (84% esterification degree) in water and then adding 1 g of freeze dried HSA. Then 6 ml of the aqueous solution newly formed are added to an organic phase of Span ® 85 in a tube and the stirrer was set at 1500 rpm. After five minutes, 4 ml of 2% (w/V) NaOH/EtOH (95% (V/V)) solution were added to the emulsion in order to trigger the transacylation reaction and stirring was maintained for further 15 minutes. To stop the reaction, 150 ml of imidazole buffer (0,05 M, pH = 7) were added and the agitation was continued for two minutes. Last, microcapsules are separated through sedimentation and washed with a 2% (w/V) polysorbate aqueous solution (Tween 20, Acros-Organics). The optimization process was supposed to be conducted thanks to design of experiments, in order to optimize granulometric distribution and yield of reaction. Design of experiments (DOE) is statistical process used in different fields as research, development and production to optimize a reaction process. This procedure allows us to establish few variables that can be changed, whereas all others are held constant since generically a process might be influenced by different factors. For this study the approach utilized is 2k factorial design in order to study all the interactions between factors The main variables are set after several studies of the whole reaction process and they are: the volume of NaOH, the speed of agitation, the nature of the oil phase, the quantity of the surfactant (Span 85) in the oil phase and the ratio between Span ® 85 and Span 20 ®. Apart from variables, we have to evaluate also responses, which are the mean of the particles size, the span of the distribution and the yield of the reaction; all of these responses are collected after each experiment. Once all the data are collected, we analyze them through design of experiments.