Vpliv topil in procesnih parametrov na izdelavo liposomov z metodo injiciranja

Štampar, Anja (author), Zupančič, Špela (mentor), Homar, Miha (comentor)

Liposomi so sodobni dostavni sistemi zdravilnih učinkovin, ki so bili razviti z namenom izboljšanja farmakokinetičnih lastnosti in s tem biološke uporabnosti učinkovin. Metoda injiciranja je ena izmed metod priprave liposomov s potencialom za prenos na masovno proizvodnjo v industrijskem merilu. Izhajajoč iz slednjega, je bil namen magistrske naloge raziskati vpliv procesnih parametrov na izdelavo liposomov; njihovo velikost, porazdelitvijo velikosti ter zeta potencial pred in po membranskem ekstrudiranju, pri uporabi različnih organskih topil, ki v literaturi še niso dobro raziskana, za izbrane pomožne snovi. Topila smo izbirali glede na topnost liposomskih komponent. Testirali smo naslednje procesne parametre: hitrost dodajanja organske faze v vodno fazo, volumen demineralizirane vode, hitrost mešanja ob injiciranju in temperatura med pripravo liposomov. Pri zasnovi poskusov in analizi podatkov smo upoštevali metodo načrtovanja eksperimentov. Vzorce smo ovrednotili z merjenjem velikosti, porazdelitve velikosti in zeta potenciala. Glede na topnost pomožnih snovi smo se odločili, da bomo načrtovali poskuse pri treh topilih: metanolu, zmesi metanola in etil acetata v volumskem razmerju 1:1 ter izopropanolu. S pomočjo statistične analize smo za izdelane liposome ugotovili, da modela vpliva procesnih parametrov na velikost liposomov pri vzorcih z metanolom in zmesi metanola in etil acetata nismo uspeli določiti. Pri vzorcih z izopropanolom smo dobili model s 55 % napovedno močjo, kjer ima na velikost liposomov vpliv temperatura priprave vzorca. Ker membransko ekstrudiranje omogoča poenotenje velikosti liposomov, se vpliv procesnih parametrov zabriše in modela ni mogoče postaviti. Modela za določitev zeta potenciala liposomov pred in po ekstruziji tudi ni mogoče postaviti, saj je vrednost zeta potenciala odvisna predvsem od komponent, ki sestavljajo liposome. Glede na procesne parametre se je spreminjal zaostanek topila v vzorcih, ki je najnižji pri hitrem mešanju, visoki temperaturi segrevanja, velikem volumnu vodne faze (velja le za metanol). Glede na eksperimentalne rezultate, smo potrdili tudi ponovljivost temperature segrevanja in hitrost dodajanja raztopine lipidov v organski fazi.

• Language: Slovenian
• Keywords: liposomi, metoda injiciranja, načrtovanje eksperimentov, procesni parametri
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2022
• PID: 20.500.12556/RUL-137565
• Publication date in RUL: 22.06.2022

Secondary language

• Language: English
• Title: The impact of solvents and process parameters on the preparation of liposomes by injection method

Abstract

Liposomes are modern delivery systems for active substances that have been developed to improve the pharmacokinetic properties and thus the bioavailability of active substances. The injection method is one of the methods for the preparation of liposomes with the potential to be transferred to the mass production on an industrial scale. Starting from the latter, the aim of this thesis was to investigate the influence of process parameters on the production of liposomes; their size, size distribution and zeta potential before and after membrane extrusion, using different organic solvents, which are not yet well studied in the literature, for selected excipients. The solvents were chosen according to the solubility of the liposomal components. The following process parameters were tested: organic phase addition rate, volume of demineralised water, stirring speed at injection and temperature during liposome preparation. The experimental design and data analysis followed the design of experiments method. Given the solubility of the excipients, we decided to design the experiments using three solvents: methanol, a mixture of methanol and ethyl acetate (1:1 (V/V)), and isopropanol. Statistical analysis revealed that we were unable to determine a model for the effect of process parameters on liposome size for methanol and mixture of methanol and ethyl acetate samples. For isopropanol samples, we obtained a model with 55 % predictability, where the liposome size is influenced by the sample preparation temperature. Since membrane extrusion makes the liposome size uniform, the influence of process parameters is blurred and the model cannot be established. A model for the estimation of the zeta potential of liposomes before and after extrusion is also not possible as the zeta potential value depends on the components of the liposomes. Depending on the process parameters, the solvent residual in the samples varied, being lowest with rapid mixing, high heating temperature, large volume of aqueous phase (only for methanol). According to the experimental results, we also confirmed the reproducibility of the temperature during liposome preparation and the organic phase addition rate.

• Keywords: liposomes, injection method, design of experiments, process parameters