Sinteza in vrednotenje molekularno vtisnjenih polimerov za ekstrakcijo bupivakaina

Lamovšek, Lea (author), Trontelj, Jurij (mentor), Kosjek, Tina (co-mentor)

Priprava vzorca je ključna za ponovljivost in občutljivost analizne metode. V okviru te naloge smo želeli razviti material z visoko učinkovito in hkrati selektivno vezavo analita bupivakaina iz bioloških vzorcev z metodo priprave molekularno vtisnjenih polimerov (MIP), ki jih uporabimo kot adsorbent pri ekstrakciji na trdni fazi. V okviru magistrske naloge smo zato sintetizirali MIP za zdravilno učinkovino bupivakain. V prvem koraku smo sintetizirali različne MIP-e s spreminjanjem razmerja komponent v polimerizacijski zmesi in pogojev, pri katerih polimerizacija poteče. Po odstranitvi matrične molekule smo z uporabo tekočinske kromatografije z visoko ločljivostjo (HPLC) določili njihove vezavne lastnosti. Najuspešnejši MIP v smislu največje afinitete in kapacitete, predvsem pa najboljše selektivnosti, smo nato sintetizirali v večji količini. Sintetiziranemu MIP-u smo odstranili matrično molekulo s pomočjo Soxhletove ekstrakcije in določili njegove vezavne lastnosti. Preverili smo uporabnost MIP-a kot sorbenta pri ekstrakciji na trdni fazi (SPE), pri čemer smo določili izkoristek ekstrakcije in metodo v nadaljevanju optimizirali za izboljšanje izkoristka. MIP, ki smo ga sintetizirali v večji količini, ima v vodi kapaciteto 5,00 mg/g, afiniteto 9,80 mL/g in faktor vtisnjenja 2,65. Z modifikacijami sinteze nam je uspelo sintetizirati polimer, ki ima boljše vezavne lastnosti, kot polimer, sintetiziran po postopku iz literature. Pri testiranju primernosti MIP-a za ekstrakcijo na trdnem nosilcu smo dobili 70 % izkoristek, faktor vezave pa je za 2,33× večji kot za nevtisnjeni polimer (NIP). Na podlagi dobljenih rezultatov lahko zaključimo, da je sintetizirani sorbent primeren za uporabo v analiznem postopku. Z validacijo HPLC metode smo dokazali, da je le-ta primerna za namen karakterizacije sintetiziranih MIP, in sicer z vidika učinkovitosti in specifičnosti vezave, kot tudi z vidika problematike odpuščanja matrične molekule, ki je pogosto problem sintetiziranega materiala. V nadaljevanju bi bilo treba raziskati, ali je sorbent primeren za uporabo na realnih vzorcih plazme.

• Language: Slovenian
• Keywords: priprava vzorcev, ekstrakcija na trdni fazi, molekularno vtisnjeni polimeri, tekočinska kromatografija visoke ločljivosti
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2021
• PID: 20.500.12556/RUL-133270
• Publication date in RUL: 19.11.2021

Secondary language

• Language: English
• Title: Synthesis and evaluation of molecularly imprinted polymers for the extraction of bupivacaine

Abstract

Sample preparation is essential for the reproducibility and sensitivity of the analytical method. In the context of this thesis, we wanted to develop a highly efficient and at the same time selective preparation method with molecularly imprinted polymers (MIP) to be used as adsorbent in solid-phase extraction (SPE). Within this framework we synthesised a MIP for an active pharmaceutical substance bupivacaine. As a first step, different MIPs were synthesised using varying polymerisation ingredients and at different polymerisation conditions. After removing the template, their binding properties were assessed using high-performance liquid chromatography (HPLC). The best performing MIP in terms of its superior affinity and capacity, and especially selectivity was then prepared in a higher amount. The synthesised MIP was washed off the template by Soxhlet extraction, and its binding properties were analysed. In the next step, the suitability of the MIP as an SPE sorbent was tested by determining. The extraction efficiency was determined, and the extraction process was further optimised to achieve a higher efficiency. The MIP synthesised in larger quantities has a capacity of 5,00 mg/g in water, an affinity of 9,80 mL/g and an imprinting factor of 2,65. By modifying the synthesis, we were able to synthesise a polymer that has better binding properties than the polymer synthesised according to the literature procedure. When testing the suitability of the MIP for solid phase extraction, we obtained a 70 % recovery and a binding factor 2.33 times higher than that of the NIP. Based on the results, it can be said that the synthesised sorbent is suitable for use in the analytical procedure. Through validation of the HPLC method, we have confirmed that it is suitable for the characterisation of synthesised MIPs in aspects of binding efficiency and specificity, as well as in aspects of template leaching, which is often a problem in synthesised materials. Further investigation would be needed to determine whether the sorbent is suitable for use on real plasma samples.

• Keywords: sample preparation, solid phase extraction, molecularly imprinted polymers, high performance liquid chromatography