title: Photostable Solid Dispersion of Nifedipine by Porous Calcium Silicate.
abstract: Nifedipine (NIF) is a typical light-sensitive drug requiring protection from light during manufacture, storage, and handling of its dosage forms. The purpose of this study was to evaluate the utility of porous calcium silicate (PCS) for maintaining the photostability of NIF in a solid dispersion formulation. Adsorption solid dispersion (ASD) prepared using NIF and PCS as an amorphous formulation was more stable to light irradiation than a physical mixture of NIF and microcrystalline cellulose (a control physical mixture) as a crystalline formulation. In addition, PCS in physical mixtures with NIF adequately protected NIF from photodegradation, suggesting that this protective effect could be because of some screening effect by the porous structure of PCS blocking the passage of light reaching NIF in pores of PCS. These findings suggest that PCS is useful for improving the solubility and photostability of NIF in solid dispersion formulation.
authors.affiliation: Department of Pharmaceutics, School of Pharmaceutical Sciences, Mukogawa Women's University.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Hirai
authors.forename: Tomoka
authors.initials: T
authors.lastname: Takatani-Nakase
authors.forename: Koichi
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D009543:Nifedipine / Q000737:chemistry*; D010316:Particle Size; D055668:Photochemical Processes; D016062:Porosity; D017640:Silicates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D017610:Calcium Compounds; D017640:Silicates; D009543:Nifedipine; C031293:calcium silicate