QbD Enabled Formulation Development of Nanoemulsion of Nimodipine for Improved Biopharmaceutical Performance

Purpose The objective of the current research is to formulate a nanoemulsion (NE) of nimodipine (ND) to improve its oral bioavailability and stability by adopting a scientific and systematic quality-by-design (QbD) approach. Methods Triacetin (oil), Cremophor RH40 (surfactant), and PEG600 (co-surfactant) were selected to formulate NE. Factors affecting critical quality attributes (CQA) were screened by Taguchi design followed by Box-Behnken design (BBD) enabled optimization. The optimized NE was further lyophilized with trehalose (cryoprotectant) to improve the storage stability. Results Optimized NE (F4), and its lyophilized NE showed globule size less than 200 nm with more than 75% drug diffusion within 30 min. Both NE (F4) and its lyophilized NE exhibited a fivefold increase in area under the curve in comparison to an aqueous dispersion of ND. Lyophilized F4 showed better stability due to the conversion of NE into solid form by lyophilization. Conclusion Lyophilized NE of ND can be prepared for improved oral bioavailability and stability. The above approach is simple, cost-effective, and scalable to manufacture on a commercial scale. Graphical Abstract