Cilnidipine is a dihydropyridine calcium channel blocker used to improve the neurological outcome following subarachnoid hemorrhage. It belongs to BCS class II drugs that have a low oral bioavailability of 13%, thus preparation as nanoparticles would be expected to improve bioavailability. The aim of the study is to prepare Cilnidipine as nanoparticles using different carriers and co-carriers, concentrations, and types. Cilnidipine nanoparticles were prepared by a solvent anti-solvent method using different carriers (Soluplus®, Poloxamer 188, PVA cold) with co-stabilizers (PEG200, glycerol) at different ratios. Based on the obtained results, formula N4, which included Soloplus in a 5:5:1.19 weight ratio of drug to the polymer to co-stabilizer, exhibited a particle size of 88.89 nm when stirred at 1000 rpm with an injection speed of 1 mL/min. The polydispersity index (PDI) for this formula was measured at 0.2413. Furthermore, formula N4 demonstrated an impressive 92.2% drug content and an entrapment efficiency (EE) of 95.8%, giving 100% release in 30 min.
