Dissolution test on 5 kinds of commercial tablets A-E of water-insoluble vitamin, phytonadion, was performed by USPX VIII method with and without a non-ionic surfactant, polysorbate 80. In addition, a study was made on the pharmaceutical properties of tablets as follows : weight variation, hardness, abrasion, content and disintegration time. Our findings suggested that the effect of the surfactant on the dissolution of phytonadion was achieved by the enhancement of solubilization and wetting of the surface of insoluble granular particles. In the presence of polysorbate 80 at higher levels than the critical micelle concentration (cmc), the influence of the surfactant on phytonadion dissolution varied from brand to brand, and the dissolution ratios increased with increment of the concentration of polysorbate 80 except for one case, which showed a specifically increasing tendency at the region of cmc. However, the maximal dissolution ratio never exceeded 65.0±2.9% (brand C) when the basket was rotated at 50 rpm, and 68.5±10.8% (brand A) at 100 rpm after 90 min. Minimal dissolution ratios at 50 rpm and 100 rpm were 5.8±2.9 and 12.6±3.2% (brand D), respectively.
