Določanje topnosti in porazdelitvenega koeficienta strukturno raznolikih spojin, delujočih na različne tarče

Mlakar, Anja (author), Ilaš, Janez (mentor)

Peroralna uporaba zdravil je aplikacija izbora. Za lažje doseganje peroralne uporabe na novo sintetiziranih učinkovinah je Lipinski v pravilu petic opisal fizikalno-kemijske lastnosti, ki so statistično značilne za peroralno uporabne spojine. V magistrski nalogi smo spojinam določili nekaj teh lastnosti ter predstavili optimalne vrednosti, ki vplivajo na farmakokinetiko različnih učinkovin. Najpomembnejša lastnosti, ki vpliva na farmakokinetiko spojin, je topnost. Od topnosti je odvisno, ali se bo učinkovina absorbirala, porazdelila in kako hitro bo delovala vpliva tudi na njen metabolizem in eliminacijo iz telesa. Z metodo stresanja smo določali termodinamično in kinetično topnost s predhodno pripravljeno umeritveno koncentracijsko krivuljo. Pri kinetični topnosti smo v fosfatni pufer pH 7,4 dodali osnovno raztopino DMSO, pri termodinamični pa smo spojino direktno zmešali s fosfatnim pufrom pH 7,4. Dobili smo zelo raznolike rezultate; od zelo dobro topnih spojin, katerih topnost je višja od 1 mg/mL, do spojin, katerih topnost je zelo slaba, in spojin, ki pri pogojih določanja topnosti razpadejo. Metabolizem prvega prehoda spojin smo določali s frakcijo S9 encima. Metabolizem pomembno vpliva na čas zadrževanja učinkovine v telesu ter koncentracijo, ki bo prisotna na mestu delovanja. Aktivnost encima smo vrednotili z določanjem metabolizma testosterona. Metabolna stabilnost spojin je pomemben kriterij pri razvoju novih zdravilnih učinkovin, zato je metoda za hitro določanje nujna za oceno potencialno peroralno uporabnih učinkovinah. Tretja lastnost, ki smo jo v okviru naloge preučevali, je bila lipofilnost učinkovin. Na permeabilnost spojin najbolj vplivajo lipofilnost, pKa, molekulska masa ter nekatere fizikalne lastnosti. Permeabilnost spojin smo določili z merjenjem logD7,4 v oktanolu in pufru pH 7,4 z metodo stresanja. Koncentracije analitov za določitev lastnosti smo izmerili z UHPLC sistemom, sklopljenim z DAD detektorjem, z reverznofazno kromatografijo ter uporabo računalniškega programa Chromeleon.

• Language: Slovenian
• Keywords: kinetična in termodinamična topnost, metabolizem, logD, metoda stresanja
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2024
• PID: 20.500.12556/RUL-156313
• Publication date in RUL: 19.05.2024

Secondary language

• Language: English
• Title: Determination of solubility and distribution coefficient of structurally diverse compounds acting on different targets

Abstract

Oral administration of medicines is an application of choice. To facilitate the achievement of oral administration of newly synthesised active substances, Lipinski described in the rule of five the physicochemical properties that are statistically significant for orally administered compounds. In this thesis, we have determined some of these properties for the compounds and presented the optimal values that influence the pharmacokinetics of the different active substances. Solubility influences all pharmacokinetic properties, determines whether an active substance will be absorbed, distributed and how fast it will act, and it also affects its metabolism and elimination from the body. The thermodynamic and kinetic solubility was determined by the flask shake method using a pre-prepared calibration concentration curve. For kinetic solubility the stock solution was added to phosphate buffer 7,4, and for thermodynamic solubility, the compound was mixed directly with phosphate buffer. The first-pass metabolism of the compounds was determined by the fraction of S9 enzyme. Metabolism influences how long the active substance will be in the body and in which concentration it will arrive at the site of action. The enzyme activity was evaluated by concurrent metabolism of testosterone. Metabolic stability of compounds is an important criterion for development and therefore a method for rapid determination in the first stages of development could be essential for potentially orally useful active substances. The third property that was studied in the context of the thesis was the lipophilicity of the active substances. Lipophilicity, pKa, molecular weight and some physical properties are the most important influences on the permeability of compounds. The permeability of the compounds was determined by measuring logD7.4, in octanol and buffer phosphate 7,4, using the flask shake method. The concentrations of the analytes for the determination of the properties, were measured using a UHPLC system coupled to a DAD detector, reversed-phase chromatography and using the Chromeleon computer program.

• Keywords: kinetic and thermodynamic solubility, metabolism, logD, flask shaking method