Taketoshi Ito

Skin penetration by indomethacin is enhanced by use of an indomethacin/smectite complex

Abstract The effect of indomethacin/smectite complex on skin penetration enhancement of indomethacin in cataplasm has been examined. Complexation with smectite increases the stability of amorphous indomethacin resulting in a complex that is more skin-permeable than the free drug.

Relationship between Hydrogen-bond Conditions of Surface Adsorbed Water and Interparticle Binding Force on Pharmaceutical Tablets

Influence of water contents to the pharmaceutical tablet strength is known empirically, and participation of hydrogen bonding force among adsorbed water molecules has been presumed. However, the detailed mechanisms of hydrogen bonding phenomena have not been reported. In this study, the hydrogen bonds states of the surface adsorbed waters on the excipient particles of the tablets were focused upon, and the relationship to the interparticle binding force determined by the Rumpf equation was discussed using a near-infrared spectroscopy (NIR). As for the results, NIR peaks of OH groups of surface water were shifted by a humidity change, and the degrees of the peak shifts correlated to interparticle binding force.