Preparation and characterization of triamterene complex with ascorbic acid derivatives.

The purpose of this study was to prepare solid dispersions of triamterene (TRT) with ascorbic acid (AA) or ascorbic acid 2 glucoside (AA2G) and to evaluate their physical properties. Solid dispersions were prepared by dissolving each sample in an organic solvent and evaporation (EVP). Powder X-ray diffraction (PXRD) revealed a halo pattern for EVP1 (AA/TRT =1/1) and EVP2 (AA2G/TRT =1/1). In differential scanning calorimetry (DSC), endothermic peaks due to the melting of TRT and AA disappeared for EVP1 (AA/TRT =1/1), and the melting peaks of TRT and AA2G disappeared for EVP2 (AA2G/TRT =1/1). Fourier transform infrared (FT-IR) spectroscopy revealed broadened peaks for EVP1 (AA/TRT =1/1) and EVP2 (AA2G/TRT =1/1) due to the hydroxyl groups (-OH) of AA and the amino groups (-NH2) of TRT and also revealed a peak shift due to the pteridine skeleton (C = N) of TRT. In near-infrared absorption (NIR) spectroscopy, peaks due to the hydroxyl groups (-OH) of AA and AA2G were found for EVP1 (AA/TRT =1/1) and EVP2 (AA2G/TRT =1/1), respectively. A peak due to the amino groups (-NH2) was evident. This suggested the formation of a evaporation, in which TRT interacted with AA or AA2G. In the dissolution test, the dissolved fraction of TRT alone after 3 minutes was 30%, whereas the fractions were enhanced to approximately 90% for EVP1 (AA/TRT =1/1) and EVP2 (AA2G/TRT= 1/1). Results confirmed that dissolution properties were improved as a result of complex formation. The above findings indicated improvement the dissolution properties of TRT.