2.5.2. Percent Drug Entrapment Efficiency and Percent Drug Loading

Formulations were filled in vials and centrifuged at 15,000 rpm using an ultracentrifuge (Remi Motors, Mumbai, India) for 25 min to separate the supernatant and pellets. The pellets were dissolved in methanol, and the drug contents were measured using HPLC. Entrapment efficiency and drug loading were calculated using the formula described in the literature [28].


**Table 2.** Coded and actual values of fractional factorial design batches.
