Preparation and characterization of triamterene complex with ascorbic acid derivatives

Abstract

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 an evaporation, in which TRT interacted with AA or AA2G. In the dissolution test, the dissolved fraction of TRT alone after 3 min 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.

Keywords:

• Ascorbic acid 2-glucoside
• triamterene
• evaporation
• dissolution
• solid dispersion

Acknowledgements

The authors thank Dr. T. Tarumi of Japan Buchi Co., Ltd. for his helpful advice regarding NIR absorption spectroscopy. The authors are grateful to Hayashibara Co., Ltd. for supplying AA2G. The authors also thank Mr. Toshifumi Sakurai for his assistance in the conduct of this experiment.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Figure 7. NIR absorption spectra of AA/TRT and AA2G/TRT systems. (a) AA/TRT, (b) AA2G/TRT.

Figure 8. s-derivative NIR absorption spectra of AA/TRT systems. (a) Amine group stretching, (b) Amine group stretching and Hydroxyl group, (c) Hydroxyl group.

Figure 9. s-derivative NIR absorption spectra of AA2G/TRT systems. (a) Amine group stretching, (b) Amine group stretching and Hydroxyl group, (c) Hydroxyl group.

Figure 10. Dissolution profiles of AA/TRT and AA2G/TRT systems. Results were expressed as mean ± S.D.(n = 3).

Additional information

Funding

This research was supported by Josai University.