2.4.1. Determination of Entrapment Efficiency

Entrapment efficiency (EE) was determined directly by calculating the amount of B12 encapsulated in lipid vesicle dispersions using the following equation (Equation (1)) [48]:

$$\rm EE(\%) = (Q\_e/Q\_l) \cdot 100 \tag{1}$$

where Q<sup>e</sup> is the amount of B12 encapsulated, and Q<sup>t</sup> is the amount of B12 used for batch preparation.

For this, 0.5 mL of lipid vesicles dispersion was incubated for 1 h with a mixture of water:methanol:sodium doceyl sulfate 1% (45:45:10) to dissolve all the vesicle components [49–51]. The final mixture was filtered, and B12 content was analysed by HPLC.
