Among the natural cyclodextrins (CyDs), bioadaptable γ-cyclodextrin (γ-CyD) is particularly useful in the design of CyD-based pharmaceutical formulations. In addition, the multi-functional characteristics of 2,6-di-O-methyl-β-CyD (DM-β-CyD) is capable of alleviating the undesirable properties of drug molecules through the formation of inclusion complexes. The objective of this contribution is to outline the recent findings on the potential of γ-CyD and DM-β-CyD as advanced drug carriers, focusing on their ability to increase the drug absorption across biological barriers, the ability to control the rate and time profiles of drug release, and the ability to deliver adrug to a targeted site. Moreover, a novel approach for the selective isolation of Ostwald's intermediate of metastable polymorphs occurring during an early stage of crystallization will be discussed by utilizing the complex formed with DM-β-CyD.

The solid dispersion method, by which a drug is amorphously dispersed in a carrier, is one of the pharmaceutical approaches most commonly employed to increase the bioavailability of poorly water soluble drugs. In the extruding method performed by various operations that combine heating, pressurization, kneading and extruding at the same time, solid dispersion can be generated continuously and in large quantities.

In this study, we prepared a solid dispersion of Pranlukast hydrate (ONON) as a model drug using Hydroxypropylmethylcellulose (HPMC) as a carrier using a twin screw extruder. At that time, we investigated the nature of the solid dispersion obtained by examining crystallinity, solubility and interaction between drug and carrier under changes in the extrusion conditions, operation temperature and the kind and quantity of additive liquid. Additionally, solid dispersion was compared with physical mixture.

As a result, we could not only improve the solubility but also facilitate handling the machine by adding an appropriate concentration of Tween 80 solution. Moreover, the drug crystallinity disappeared in solid dispersion produced under all extrusion conditions, regardless of temperature. But the extrusion pressure increased as the operation temperature decreased, and the solubility of solid dispersion produced under lower temperatures was better than that produced under higher temperatures.

Based on the findings described above, we could improve the dissolution property of this drug remarkably by selecting an appropriate extrusion temperature as well as the kind and concentration of additive liquid.

Recently tablets that can rapidly disintegrate in the oral cavity have attracted attention as a novel dosage form that can be taken easily and safely even by infants and elderly people. The aim of the present research was, by ordinary equipment, to develop rapidly disintegrating tablets that have satisfactory physical hardness. In this report, rapidly disintegrating tablets were prepared using direct compression methods. Tablet properties, such as porosity, hardness, swelling ability, wetting time, disintegration time, etc., were evaluated, and the formulations and preparation conditions were optimized by different kinds of additives, the content of additives, compression pressure, etc. Furthermore, disintegration mechanisms of the tablets were clarified. It was possible to prepare an oral rapidly disintegrating tablet with the targeted physical properties for the present study, i. e., hardness of more than 30 N, a disintegration time of less than 30 seconds and friability of less than 0.5%, by direct compression at 0.4 t compression pressure by using 3% of crospovidone as a disintegrant, 0.3% of magnesium stearate as a lubricant and 10% of crystalline lactose as a core particle. The rapid disintegration of tablets was mainly due to the porous structures and wetting.