Liposomes as a carrier for 4–hydroxycoumarin: characterisation, stability and antioxidant potential

Abstract

<p>The aims of the present research were to develop and characterize 4-hydroxycoumarin-loaded liposomes <em>via </em>the determination of encapsulation efficiency, antioxidant capacity, vesicle size, polydispersity index (PDI), zeta potential, conductivity, mobility, density, surface tension, viscosity, and 60-day storage stability. The encapsulation efficiency of 4-hydroxycoumarin in liposomal particles was 96.7 ± 1.2%. The ABTS and DPPH radical scavenging capacity of the prepared liposomes was 89.76 ± 0.56% and 93.18 ± 0.23%, respectively, whereas cupric ion-reducing antioxidant capacity amounted to 0.367 ± 0.003 mmol Trolox equivalent (TE)/L. The density of liposomes with 4-hydroxycoumarin was 1.007 ± 0.002 g/cm<sup>3</sup>, surface tension was 22.7 ± 0.2 mN/m, and viscosity was 14.3 ± 0.2 mPa·s. Vesicle size and PDI of 4-hydroxycoumarin-loaded liposomes were changed from 1286.3 ± 73.8 nm to 2077.3 ± 63.2 nm and from 0.409 ± 0.050 to 0.676 ± 0.064, respectively, during the 60-day stability study. The zeta potential of the obtained liposomes was changed from -16.73 ± 0.47 mV to -10.31 ± 0.42 mV, while mobility varied from -1.311 ± 0.036 µmcm/Vs to -0.806 ± 0.031 µmcm/Vs. The conductivity did not change during 60 days and amounted to approximately 0.020 mS/cm. Overall, due to the high encapsulation efficiency and antioxidant capacity, the obtained results qualify liposomes to be used as 4-hydroxycoumarin carriers for future examination of its biological activities and potential application in medicine and pharmaceutical products. However, future experiments should include the optimization of the liposomal composition with the aim of improving 4-hydroxycoumarin-loaded liposome stability.</p>