Analiza parametrov metode lipolize in vitro na osnovi raziskav, opisanih v literaturi

Skornšek, Nina (author), Bogataj, Marija (mentor), Rede, Katarina (co-mentor)

Zagotavljanje ustrezne biološke uporabnosti zdravilnih učinkovin je eden izmed večjih izzivov farmacevtske industrije. Potencialno rešitev za izboljšanje biološke uporabnosti predstavlja vgrajevanje učinkovin v lipidne dostavne sisteme, med katere spadajo tudi samo- mikroemulgirajoči dostavni sistemi. Po peroralni aplikaciji so ti dostavni sistemi podvrženi prebavnim procesom, ki jih je težko ponazoriti s konvencionalnimi testi sproščanja. Te sisteme tako biofarmacevtsko vrednotimo s pomočjo modelov lipolize in vitro, ki posnemajo fiziološke pogoje prebave lipidov. Namen magistrske naloge je bil, da naredimo sistematičen pregled objavljenih študij s področja metode lipolize in vitro in analizo parametrov, ki na potek lipolize in vitro najbolj vplivajo. S pomočjo analize literaturnih podatkov, smo predlagali optimiziran model pH stat metode lipolize in vitro. V podatkovni bazi Pubmed smo sistematično iskali raziskovalne članke z opisano metodo lipolize in vitro, ki ponazarja proces lipolize na začetku tankega črevesa. Našli smo 31 raziskovalnih člankov, ki so ustrezali postavljenim vstopnim kriterijem. Podrobneje smo analizirali koncentracije površinsko aktivnih snovi, natrijevega klorida, kalcijevih ionov, vrsto in koncentracijo lipoliznega pufra ter aktivnost in izvor uporabljenih encimov. Pridobljene podatke smo grafično prikazali in jih ovrednotili. Pri vseh analiziranih parametrih smo podatke ločili glede na stanje na tešče ali po obroku. Iz podatkov smo izračunali povprečne vrednosti koncentracij, standardne deviacije koncentracij in določili koncentracijska območja soli žolčnih kislin, fosfolipidov in pufra ter natrijevega klorida. Za encim pankreasna lipaza smo izračunali povprečne aktivnosti, standardne deviacije aktivnosti in določili območja aktivnosti lipaze. Prišli smo do naslednjih ugotovitev: izmed pufrov je bil največkrat uporabljen tris-maleatni pufer, vse študije pa so potekale v pH območju 6,8-8,0. Povprečna koncentracija pufra na tešče je bila 16 mM, po obroku pa 40 mM. Največkrat uporabljena sol žolčnih kislin je bila natrijev tavrodeoksiholat v koncentraciji 4 mM na tešče in 19 mM po obroku. Fosfatidilholin je bil najpogosteje uporabljen fosfolipid. Na tešče so ga v študijah uporabili v koncentraciji 1 mM. Povprečna koncentracija kalcijevih ionov na tešče je bila 3,21 mM, po obroku pa 5 mM. Največkrat omenjen izvor lipaze je bil prašičji pankreatin. Povprečna aktivnost prašičjega pankreatina na tešče in po obroku je bila 660 USP/mL.

• Language: Slovenian
• Keywords: model lipolize in vitro, samo-mikroemulgirajoči dostavni sistemi, lipolizni medij, literaturni pregled
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2022
• PID: 20.500.12556/RUL-143536
• Publication date in RUL: 24.12.2022

Secondary language

• Language: English
• Title: Analysis of in vitro lipolysis method parameters based on studies described in the literature

Abstract

Ensuring the adequate bioavailability of active substances is one of the major challenges facing the pharmaceutical industry. A potential solution to improve bioavailability is the incorporation of active ingredients into lipid delivery systems, including self- microemulsifying delivery systems. After oral administration, these systems undergo digestive processes that are difficult to reproduce with conventional release tests. Thus, these systems are biopharmaceutically evaluated using in vitro lipolysis models that mimic physiological conditions of lipid digestion. The aim of this thesis was to perform a literature review of published studies and to analyse the parameters that have the most influence on in vitro lipolysis. Our analysis will be used to set up an optimised hypothetical model for the pH stat method of in vitro lipolysis. We systematically searched the Pubmed database for research articles describing the in vitro lipolysis method that mimics the process of lipolysis in the beginning of small intestine. We found a final 31 research articles that met the entry criteria. We detailly analysed the concentrations of surfactants, sodium chloride, calcium ions, the type and concentration of the lipolysis buffer and the activity and origin of the enzymes used. The data obtained were graphically displayed and evaluated. For all parameters analysed, we also separated the data according to fasting or fed state. From the data we calculated the mean concentrations, standard deviations and concentration ranges for bile salts, phospholipid, buffers and sodium chloride. For the pancreatic lipase data, we calculated the mean activities, standard deviations of activity and determined the lipase activity ranges. The following conclusions were reached: tris-maleate buffer was the most commonly used buffer, and all studies were conducted in the pH range 6,8 -8,0. The average fasting buffer concentration was 16 mM and the fed buffer concentration was 40 mM. The most commonly used bile acid salt was sodium taurodeoxycholate at a concentration of 4 mM fasting and 19 mM fed. Phosphatidylcholine has been the most commonly used phospholipid. In fasting studies, it has been used at a concentration of 1 mM. The average fasting calcium ion concentration was 3,21 mM and the fed concentration was 5 mM. The most frequently mentioned source of lipase was porcine pancreatin. The average fasting and fed porcine pancreatin activity was 660 USP/mL.

• Keywords: in vitro lipolysis model, self-microemulsifying drug delivery system, lipolysis medium, literature review