Razvoj in vrednotenje liposomov in transfersomov z izvlečkom grozdnih pešk

Jevšnikar, Ajda (author), Zvonar Pobirk, Alenka (mentor), Caddeo, Carla (comentor)

Uporaba stranskih produktov različnih industrij predstavlja pomemben korak k trajnostnemu razvoju in je hkrati lahko vir aktivnih spojin za nadaljnjo uporabo v farmacevtski in kozmetični industriji. Eden izmed takšnih stranskih produktov vinske industrije je grozdna tropina, ki poleg pešk vsebuje tudi kožice grozdja in peclje. Zanimanje za te surovine narašča, saj je izvleček grozdnih pešk bogat s polifenolnimi spojinami, flavonoidi in resveratrolom. Ti izkazujejo antioksidativne in protivnetne učinke, vendar so hkrati nestabilni in občutljivi na okoljske dejavnike. V okviru diplomske naloge smo zato razvili in ovrednotili liposome ter transfersome kot nosilce izvlečka grozdnih pešk za dermalno in peroralno uporabo. Vezikularni sistemi so bili pripravljeni s soniciranjem in vrednoteni glede na velikost delcev, polidisperzni indeks, zeta potencial, enkapsulacijsko učinkovitost ter antioksidativno delovanje. Ciljni parametri so bili povprečna velikost delcev približno 80 nm, polidisperni indeks <0.3 in zeta potencial okoli ±30 mV. Vgradnja izvlečka ni bistveno vplivala na fizikalno stabilnost, testi DPPH in FRAP pa so potrdili ohranjeno antioksidativno aktivnost po enkapsulaciji. Učinkovitost enkapsuliranja katehina in epikatehina je bila visoka v obeh tipih nosilcev. Za peroralno aplikacijo so bile formulacije dodatno prilagojene z vključitvijo kationskega surfaktanta in oblogo z gastrorezistentnim polimerom (Eudragit® L100). Rezultati so pokazali dobro stabilnost med shranjevanjem ter večjo odpornost na simulirane gastrointestinalne pogoje pri obloženih transferosomih. Čeprav se je zeta potencial zmanjšal na skoraj nevtralne vrednosti, je polimerni sloj zagotovil sterično stabilizacijo in preprečil povečanje velikosti delcev. Zaključimo lahko, da liposomi in transferosomi učinkovito omogočajo vgradnjo izvlečka ter ohranjajo njegovo antioksidativno aktivnost. Dermalne formulacije so se izkazale kot nekoliko ugodnejše zaradi ravnotežja med stabilnostjo in vgradnjo, medtem ko so obloženi transferosomi pokazali boljšo odpornost v gastrointestinalnih pogojih, kar potrjuje njihovo primernost za peroralno uporabo.

• Language: Slovenian
• Keywords: liposomi, transferosomi, izvleček grozdnih pešk, enkapsulacijska učinkovitost, antioksidativno delovanje
• Work type: Bachelor thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2025
• PID: 20.500.12556/RUL-173419
• Publication date in RUL: 17.09.2025

Secondary language

• Language: English
• Title: Formulation and characterization of grape pomace extract-loaded liposomes and transfersomes

Abstract

The utilisation of industrial by-products represents an important step towards sustainable development and simultaneously provides a valuable source of bioactive compounds for further use in pharmaceutical and cosmetic industry. One such by-product of the wine industry is grape pomace, which contains seeds, skins, and stems. Interest in these raw materials is increasing, since grape pomace extract is rich in polyphenolic compounds, flavonoids, and resveratrol, known for their antioxidant and anti-inflammatory effects. However, these bioactives are unstable and sensitive to environmental factors. In this thesis, liposomes and transfersomes were developed and evaluated as carriers of grape pomace extract for dermal and oral application. Vesicular systems were prepared by sonication and characterised in terms of particle size, polydispersity index, zeta potential, entrapment efficiency, and antioxidant activity. The target parameters were an average particle size of approximately 80 nm, polydispersity index <0.3, and zeta potential around ±30 mV. Incorporation of the extract did not significantly affect physicochemical stability, while DPPH and FRAP assays confirmed preserved antioxidant activity after entrapment. Entrapment efficiency of catechin and epicatechin was high in both liposomes and transfersomes. For oral application, formulations were further optimised by incorporating a cationic surfactant and coating with a gastro-resistant polymer (Eudragit® L100). The results demonstrated good storage stability and improved resistance under simulated gastrointestinal conditions for coated transfersomes. Although the zeta potential decreased to nearly neutral values, the polymeric layer ensured steric stabilisation and prevented particle size increase. In conclusion, liposomes and transfersomes effectively enabled entrapment of grape pomace extract and preserved its antioxidant activity. Dermal formulations proved slightly more favourable due to their balance between stability and entrapment, while coated transfersomes exhibited superior robustness under gastrointestinal conditions, confirming their potential for oral application.

• Keywords: liposomes, transfersomes, grape pomace extract, entrapment efficiency, antioxidant activity