Controlled-release oral dosage forms containing nimodipine solid dispersion and hydrophilic carriers

The aim of this study was to prepare solid dispersion of nimodipine (NMD) by solvent evaporation method to overcome the poor water solubility of NMD, and to formulate controlled-release (CR) tablets containing the NMD solid dispersion. NMD is a dihydropyridine calcium-channel antagonist that is practically insoluble in water. Owing to the short half-life of the drug in the plasma, NMD immediate-release tablets should be administered frequently for the treatment and prevention of ischemic disorders following aneurysmal subarachnoid hemorrhage. In this study, solid dispersion technique was applied to increase the low solubility of NMD. Carriers for solid dispersions were prepared with different kinds of hydrophilic polymers. Kinetic solubility studies were performed for the prepared solid dispersions, using sodium acetate buffer (pH 4.5). Solid dispersions were then characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared spectrometry (FT-IR). CR tablets containing the NMD-PVP K30 solid dispersions were designed to reduce the dosing interval and increase patient compliance. Hydroxypropyl methylcelluloses (HPMC) were used as release-modifiers, and lactose anhydrous as a diluent.

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