title: [Equivalence studies of pravastatin original and generic drugs by dissolution test].
abstract: There are various opinions regarding the different functions of original and generic drugs. We used the paddle method to perform dissolution tests on pravastatin sodium tablets (10 mg) to investigate the causes for these differences. We used water and buffer solutions adjusted to pH 1.2 (JP1) and pH 6.8 (JP2), which are described in the Japanese Pharmacopoeia. The pravastatin concentration was measured by UV spectroscopy and HPLC. There were significant differences in the percentages dissolved of original and generic drugs after 5 and 10 min. On the other hand, the dissolution behaviors using water and JP2 measured by HPLC were similar to the results obtained by UV spectroscopy. However, the percentage dissolved of pravastatin using JP1 decreased with time because pravastatin degraded in JP1. There were also significant differences in the pravastatin concentrations of the original and generic drugs at 5, 15, 30, and 45 min. Based on the above results, since the original drug has a slower dissolution rate than the generic drugs, it is necessary to be cautious about the degradation of pravastatin in the stomach and the bioavailability of pravastatin due to the different dissolution rates and the different residual amount of pravastatin in the stomach.
authors.affiliation: Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Nakauchi
authors.forename: Ena
authors.initials: E
authors.lastname: Takeuchi
authors.forename: Takuya
authors.initials: T
authors.lastname: Okamoto
authors.forename: Katsuya
authors.initials: K
authors.lastname: Teramoto
authors.forename: Aoi
authors.initials: A
authors.lastname: Nozaki
authors.forename: Fuko
authors.initials: F
authors.lastname: Seko
authors.forename: Kayo
authors.initials: K
authors.lastname: Yuminoki
authors.forename: Junichi
authors.initials: J
authors.lastname: Katakawa
authors.forename: Naofumi
authors.initials: N
authors.lastname: Hashimoto
mesh_terms: D002851:Chromatography, High Pressure Liquid; D016568:Drugs, Generic / Q000032:analysis; D017035:Pravastatin / Q000032:analysis*; D012995:Solubility; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet
chemical_list: D016568:Drugs, Generic; D012996:Solutions; D017035:Pravastatin