Formulation, Characterization and Optimization of Liposomes Containing Eicosapentaenoic and Docosahexaenoic acids; A Methodology Approach

Omega-3 fatty acids (FAs) have been shown to prevent cardiovascular disease. The most commonly used omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are highly vulnerable to oxidation and therefore, have short shelf life. Recent advances in nanoliposomes provided a biocompatible system for stabilizing omega-3 FAs. Several methods could be implemented to prepare nanoliposomes. To the best of our knowledge, the performances of these methods in preparation omega-3 FAs have not been examined. Nanoliposomes were prepared by thin film hydration followed by one of the following 1- extrusion, ultrasonic irradiation; 2- bath sonication; 3- probe sonication; or 4- combined probe and bath sonication. The size of liposomes obtained from methods 1 to 4 were 99.7 ± 3.5, 381.2 ± 7.8, 90.1 ± 2.3, and 87.1± 4.10 nm with ξ potential being -42.4 ± 1.7, -36.3 ± 1.6, -43.8 ± 2.4, and 31.6 ± 1.9 mV, respectively. The encapsulation efficiency (EE) for DHA was 13.2 ± 1.1%, 26.7 ± 1.9%, 56.9 ± 5.2%, and 51.8 ± 3.8% for methods 1 to 4, respectively. The corresponding levels for EPA were 6.5 ± 1.3%, 18.1 ± 2.3%, 38.6 ± 1.8%, and 38 ± 3.7%, respectively. The EE for DHA and EPA of liposomes for both methods 3 and 4 increased significantly (p < 0.05). Propanal, as the major volatile product formed during liposomal preparations, amounts from 81.2 ± 4.1 to 118.8 ± 2.3 µgg-1.