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Compressibility and dissolution property of mefenamic acid, which exhibited poorly binding and water soluble properties, was improved by the mechanofusion process using dry inorganic materials. The surface free energy of coated particles and the hardness and dissolution rate of compressed tablets were investigated. The polar component of the surface free energy for mefenamic acid particle was increased by coated with inorganic material, and the hardness and dissolution rate of compressed tablet increased as the polar component of processed powder increased. Hence improvements of compressibility and dissolution property would be attributed to an increase of the hydroxyl groups presented on the particle surface. The surface interaction between mefenamic acid and inorganic material was studied by infrared spectroscopy. As a result, we found that mechanofusion process could produce physicochemical surface interactions between amino and carbonyl groups of mefenamic acid and hydroxyl groups of inorganic materials.

By co-grinding with β-cyclodextrin and drugs, it is suggested that drugs were included to β-cyclodextrin cavity. Ground mixture is amorphous, so that it is difficult to analyze the effect of co-grinding. This study was brought out molecular states of ground mixture and effect of co-grinding. It is suggested that change of molecular states by co-grinding was according to structure of drugs.

Inhalation has been regarded as a promising method for systematic drug delivery as well as treatment of pulmonary diseases. However, difficulty in controlling the powder characteristics is one of the major problems in this field that prevents wide application of the inhalation technology. Herein, strategies to obtain highly dispersive powders are presented, in which it was achieved by both physical and chemical approaches. Notably, addition of wrinkle structures on the particle surface significantly improved the powder dispersity. This technique may enable development of carrier-free nanoparticle inhalation therapy.

The crystalline state of drug substance, such as polymorphic forms and crystallinity, in the manufacturing process was analyzed by the Near Infrared Spectroscopy (NIR) calibrated with a set of blend mixture of polymorphs and amorphous samples. The crystalline state of drug substance in the mixture and the tablet was well analyzed by the NIR spectroscopy. However, the crystalline state of drug substance in the granule was determined only when there were no molecular interactions between the drug substance and the excipient since molecular interaction inhibited the accurate evaluation of crystalline state. Chemometrics and spectroscopic measurements will be a useful tool for the evaluation of crystalline state in dosage form when no molecular interaction occurs in the manufacturing process.