Formulation and Evaluation of Benidipine Nano-suspension by Precipitation Method using Central Composite Design

Abstract

In the interest of administration of dosage form oral route is most desirable and preferred method. Poor solubility and slow dissolution rate major challenges in upcoming and existing therapeutically active compound. Water insoluble drug indicate insufficient bioavailability as well dissolution resulting in fluctuating plasma level. Benidipine (BND) is Biopharmaceutical Classification System Class-II drug having low solubility and high permeability, antihypertensive drug has lower bioavailability. The purpose of the present study was to improve solubility as well dissolution profile of Benidipine HCL. BND nanosuspension was formulated using precipitation technique. Various polymers were evaluated viz. HPMC E15, Tween 20, PVP K30 in preliminary trial to stabilized nanosuspension but PVP K30 was selected among them. The solubility of BND was carried out using different solvents like Ethanol, Acetonitrile; Acetone. Ethanol was used as a preferred solvent as BND shows high solubility in it. The effect of different important process parameters e.g. selection of polymer concentration X1(10 mg), solvent concentration X2 (0.2 ml) were investigated by Central Composite factorial design to accomplish desired particle size and rate of dissolution. Stirring speed and time of stirring was kept constant as 1000 rpm and 2h respectively. To achieve optimized batch, 9 formulations (F1-F9) were prepared. The optimized batch had 237 nm particle size Y1, and showed in-vitro dissolution Y2 98±0.72 % in 30 mins related to pure BND (58±0.25%) and zeta potential was -15.3. None of interaction between drug and polymer was confirmed by Differential scanning calorimetry (DSC) and FT-IR analysis. The obtained results showed that issues related particle size (nm) and rate of dissolution of BND has been solved when nanosuspension can be prepared by precipitation method by considering optimized parameter due to formation of nanosized particles