7
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Processing-induced phase transitions of theophylline--implications on the dissolution of theophylline tablets.

      1 , ,
      Journal of pharmaceutical sciences
      Wiley

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Aqueous wet massing of stable anhydrous theophylline (A) with polyvinylpyrrolidone (PVP) resulted in its complete transformation to theophylline monohydrate (M). Drying at 45 degrees C, resulted in the formation of metastable anhydrous theophylline (A*) which then transformed to A. PVP, a known crystallization inhibitor, was effective in inhibiting the A* --> A transition. The higher molecular weight polymer, PVP K90, was more effective in inhibiting the A* --> A transition as compared to PVP K17. The disappearance of M, and the formation of A* and A was simultaneously monitored by XRD. An increase in the drying temperature from 45 to 55 degrees C accelerated the A* --> A transition. In granules prepared by the high-shear process, approximately 50% of theophylline existed as A and the rest as A*. In contrast, the fluid-bed granulation process yielded granules containing only A. Thus, the physical form of theophylline in tablets was influenced by the molecular weight of the binding agent, the granulation method, and the drying temperature. Using A as the starting material, tablets were manufactured by high-shear aqueous wet granulation process and the A* content was quantified. These tablets were stored under various relative humidity (RH) conditions at 25 degrees C for 2 weeks. Storage at RH >or= 33% caused complete A* --> A conversion accompanied by a pronounced decrease in the initial dissolution rate indicating that phase transitions during processing and storage can have a significant influence on product performance.

          Related collections

          Author and article information

          Journal
          J Pharm Sci
          Journal of pharmaceutical sciences
          Wiley
          0022-3549
          0022-3549
          May 2007
          : 96
          : 5
          Affiliations
          [1 ] Department of Pharmaceutics, College of Pharmacy, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, USA.
          Article
          S0022-3549(16)32242-0
          10.1002/jps.20746
          17455350
          a9dd9e4c-3561-4152-8180-64b7d13b1a21
          History

          Comments

          Comment on this article