Lyophilised nanovesicles loaded with vitamin B12

Abstract

The use of nanomaterials in recent years has shown many advantages for the production of pharmaceuticals, cosmetics, food, and food packaging. Nanovesicles are emerging as carriers of bio-compounds and drugs at a wide variety of applications due to the hydrophilic and lipophilic character of the structure: an aqueous core surrounded by a lipid layer. In this work, vitamin B12 (cobalamin) was encapsulated, due to its synergic activity with antibiotics. Moreover, this bio compound is present in several food products and pharmaceuticals products. A freeze-drying process is proposed for nanocarriers developments, due to its advantages for storage and transportation. Three types of vesicles formulations were tested: liposomes, niosomes and positively charged niosomes. Maltodextrin at 20 % concentration (w/w) was added to the formulation to protect the vesicles during the lyophilisation process. The nanovesicles particle size and morphology was characterized by Dynamic Light Scattering and Transmission Electron Microscopy, and the encapsulation efficiency by HPLC with UV–vis’s detection. The lyophilised powder was resuspended in three aqueous phases: pure water, glycerol and PEG400 aqueous solutions. An increase in the mean vesicle size was observed as a general trend. It was also studied the effect of adding vitamin B12 before or after the lyophilisation step on mean vesicles size, results indicated that vesicles were less affected in size when vitamin B12 was added before the lyophilisation step. Moreover, encapsulation efficiency (EE) of vitamin B12 in lyophilised vesicles arise values up to 70 % while the loading capacity (LC) of these systems were 100 mg/g, values obtained for liposomes when PEG400 solution was used as hydrating media, showing that the method developed for loaded lyophilised nanocarriers do not alter EE and LC.