title: Clopidogrel Napadisilate Monohydrate Loaded Surface-Modified Solid Dispersion: Physicochemical Characterization and in Vivo Evaluation.
abstract: To develop a novel solid dispersion of clopidogrel napadisilate monohydrate (CNM) with improved stability and oral bioavailability, surface-modified solid dispersions were prepared by spray-drying using water as a solvent, Tween 80 as a surfactant, and hydroxypropylmethyl cellulose (HPMC) as a hydrophilic polymer, and optimized according to drug solubility. Its solid-state characterization was evaluated by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The stability study was performed at 50°C/75% RH over a period of 6 weeks. Its dissolution profiles and oral bioavailability in rats were also compared with that of CNM and clopidogrel bisulfate (CB). The solid dispersion, composed of CNM/HPMC/Tween80 at a weight ratio of 10/2.5/2.5, in which CNM was in the crystalline state, increased the drug solubility approximately 4.6-fold. It showed a significantly better dissolution profile than that of CNM in all the dissolution media, and gave either similar or higher dissolution compared to that of CB. This solubility and dissolution enhancement was attributed to improved wetting and solubilization of CNM crystals due to hydrophilic carriers attached on the drug surface. It had excellent stability, thereby addressing the stability problem of CB powder. Furthermore, it increased the area under curve (AUC) values by about 4-fold and 1.6-fold compared to CNM and CB, respectively, suggesting that it improved the oral bioavailability of the drug in rats. Thus, this solid dispersion system prepared with water, HPMC and Tween 80 can be used to enhance the bioavailability of CNM as well as to solve the stability problem of CB.
authors.affiliation: College of Pharmacy & Institute of Pharmaceutical Science and Technology, Hanyang University.
authors.forename: Young Hun
authors.initials: YH
authors.lastname: Kim
authors.forename: Dong Wuk
authors.initials: DW
authors.lastname: Kim
authors.forename: Min Seok
authors.initials: MS
authors.lastname: Kwon
authors.forename: Kwan Hyung
authors.initials: KH
authors.lastname: Cho
authors.forename: Jong Oh
authors.initials: JO
authors.lastname: Kim
authors.forename: Chul Soon
authors.initials: CS
authors.lastname: Yong
authors.forename: Han-Gon
authors.initials: HG
authors.lastname: Choi
mesh_terms: D000818:Animals; D001682:Biological Availability; D002152:Calorimetry, Differential Scanning; D000077144:Clopidogrel; D016503:Drug Delivery Systems; D065347:Hypromellose Derivatives / Q000737:chemistry; D008297:Male; D008855:Microscopy, Electron, Scanning; D010975:Platelet Aggregation Inhibitors / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D011136:Polysorbates / Q000737:chemistry; D033362:Powder Diffraction; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D014961:X-Ray Diffraction
chemical_list: D010975:Platelet Aggregation Inhibitors; D011136:Polysorbates; D065347:Hypromellose Derivatives; D000077144:Clopidogrel; D013988:Ticlopidine