Sustained-release aspirin tablet using an insoluble matrix

✍ Scribed by Mahendra S. Vora; Arthur J. Zimmer; Paul V. Maney

• Book ID: 102913075
• Publisher: John Wiley and Sons
• Year: 1964
• Tongue: English
• Weight: 529 KB
• Volume: 53
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600530505

✦ Synopsis

mole. This value along with the predicted transition temperature gave a value for the entropy difference equal t o 4.75 e x .

Discussion

The method developed in this study to determine solubility of rapidly reverting polymorphic states was shown to work very well for sulfathiazole XI. Even though the 11-1 reversion is rapid enough to preclude equilibrium measurement, it is sufficiently slow t o allow use of this method. However, it is conceivable that reversions in other systems can be so rapid that this method will not be applicable. Thus, in systems where one form may be 10 times more soluble. the supersaturation obtained in the boundary layer may be such that instantaneous crystallization of less soluble forms will result.

It can be used to measure rapidly the effect of nucleation and crystallization inhibitors in reverting systems. I t can also be used for studying dissolution mechanism for systems that dissolve through acid.base reaction. It may also have value for studying the other factors influencing the dissolution process. More data will

The method has other applications.

487

be forthcoming to test the general applicability of this method.

Conclusions

A method suitable for the rapid determination of solubility has been developed and used to obtain solubility and thermodynamic data for sulfathiazole 11. The transition temperature predicted from these data was confirmed by an independent experiment.

REFERENCES

(1) Mullins, J. D., and Macek, T. J., THIS JOURNAL, 49, 245(1980). ~~ ( 2 ) -Almirante. L., DeCarneri. I., and Coppi, G., Farmaco Pavia E d . Pral.. 15, 471(1960).

(3) Higuchi, W. I . , Lau, P. K., Higuchi, T., and Shell,