title: Quantitative determination of amorphous nicardipine hydrochloride in long acting formula (NIC-LA) using light anhydrous silicic acid.
abstract: We investigated a method to quantitatively determine amorphous nicardipine hydrochloride (NIC) in the NIC-long acting formula (LA) model formulas prepared using NIC, light anhydrous silicic acid (LASA) and carboxymethylethylcellulose (CMEC). Consequently, since the quantity of total NIC in the formula can be determined by means of HPLC and crystal NIC can be determined by the differential scanning calorimetry (DSC) method because the heat of fusion (85.08 J/g) of NIC is constant and unaffected by excipients, we developed the HPLC-DSC method by which the quantity of amorphous NIC is calculated as the difference between the quantity of total NIC determined by HPLC and the quantity of crystal NIC determined by DSC. This practical HPLC-DSC method was confirmed to have good accuracy and reproducibility.
authors.affiliation: Pharmacovigirance Department, Yamanouchi Pharmaceutical Co., Ltd, Hasune, Itabashi-ku, Tokyo, Japan. kohinata@yamanouchi.co.jp
authors.forename: Takeru
authors.initials: T
authors.lastname: Kohinata
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Fujii
authors.forename: Souichiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Noritaka
authors.initials: N
authors.lastname: Hamada
authors.forename: Etsuo
authors.initials: E
authors.lastname: Yonemochi
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Terada
mesh_terms: D002121:Calcium Channel Blockers / Q000032:analysis*; D002138:Calibration; D002152:Calorimetry, Differential Scanning; D002266:Carboxymethylcellulose Sodium; D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009529:Nicardipine / Q000032:analysis*; D011208:Powders; D012824:Silicic Acid / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D002121:Calcium Channel Blockers; D003692:Delayed-Action Preparations; D007202:Indicators and Reagents; D011208:Powders; D012824:Silicic Acid; D009529:Nicardipine; D002266:Carboxymethylcellulose Sodium