Search

Taste-masking granules were prepared by coating granules with a taste-masking layer prepared by combining the water-insoluble and -soluble polymers, ethylcellulose and hypromellose, respectively. These granules showed an immediate drug release property after a suitable lag time. We confirmed that the dissolution behavior depended on the polymer ratio in the taste-masking layer. The result showed that the dissolution lag time and rate of the taste-masking granules were shortened and enhanced, respectively by increasing the hypromellose content. Films with the same polymer ratio as the taste-masking layer were prepared, and their physical properties were measured to evaluate the relationship between the dissolution behavior and the film properties. The tensile strength of the films decreased with an increasing concentration of hypromellose. Furthermore, there was a relationship between the tensile strength of the films and dissolution rate of the taste-masking granules. The lag time was significantly shortened when the hypromellose blending ratio exceeded 20%, and this change was suggested to be associated with the water permeability of the film. These results indicate that the tensile strength and water permeability of the films were influenced by the polymer ratio, which also influenced the dissolution behavior of the taste-masking granule.

Patient compliance can be reduced when bitter-tasting compounds, such as propiverine hydrochloride, are administered orally. Propiverine hydrochloride is an example of a drug with a bitter taste, used for the treatment of overactive bladders.This study tested whether propiverine free base palatability and aqueous solubility could be improved by crystalline complex formation.We used 42 compounds, and found 9 new propiverine crystalline complexes. The properties and solubility of these complexes were studied using a range of techniques. A taste perception study was carried out using a taste sensor to evaluate the taste masking ability of the crystalline complex formation.The melting points of the crystalline complexes were higher than that of propiverine. The dissolution rates of the crystalline complexes in aqueous buffer solution (pH 6.8) and in purified water were much faster than that of propiverine. Propiverine salicylic acid crystalline complex had substantially less bitterness than propiverine hydrochloride, which was extremely bitter.The present findings indicated that crystalline complex formation provided an effective approach to enhancing propiverine solubility, and to masking its bitter taste.Crystalline complex formation represents a useful and valuable technique for the preparation of orally disintegrating tablets and improving patient compliance, even for substances with bitter tastes.

The aim of the present study was to mask the bitterness of propiverine hydrochloride (P-4) by converting it to propiverine free base. Fine granules comprising the free base, which was converted from P-4 by desalination, were prepared. By using Fourier transform infrared spectroscopy, thermogravimetry-differential thermal analysis, and powder X-ray diffraction spectra, we confirmed that P-4 had been converted into propiverine free base by desalination during the manufacturing process. Furthermore, the conversion into free base appeared to result in decreased solubility, and both the taste testing sensor and tasting volunteers determined that it masked the bitterness of P-4. On using the gustatory sensation test, the bitterness of the P-4 fine granules was confirmed to be weakened. The dissolution rate and bioavailability of fine granules of the free base were compared with tablets of P-4. The dissolution rate and bioavailability of the fine granules and tablets were almost the same. We successfully masked the taste of P-4 by converting it into free base using a manufacturing process that was suitable for commercial manufacturing.