The Use of Polyvinyl Alcohol and Polyacrylic Acid to Inhibit the Hydrate Transformation of the Drug Theophylline
Advisor Information
Alan Gift
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
6-3-2015 2:00 PM
End Date
6-3-2015 3:30 PM
Abstract
The solid form of active pharmaceutical ingredients (APIs) in drug tablets have the potential to transform into a hydrate state. These transformations are important to understand in order to prevent unwanted transformations when the anhydrate crystals are in the presence of water. Specific polymer excipients have the ability to inhibit this anhydrate to hydrate transformation. In this study, various properties of polyvinyl alcohol (PVA) and polyacrylic acid (PAA) were investigated to better understand the factors that inhibit this theophylline transformation. Anhydrous theophylline was added to solutions containing dissolved PVA or PAA and the transformation from anhydrate to hydrate theophylline was monitored using in-line Raman spectroscopy by collecting spectra every 30 seconds. A calibration model was used to quantify the extent of the transformation for each of the collected Raman spectra, which was then used to construct transformation profiles. The results showed that the inhibition of theophylline was dependent on chain length and percent hydrolysis of the polymer. In addition, intrinsic dissolution and solubility tests were performed to further examine the mechanism of this inhibition. These results indicate that the presence of PVA or PAA had little to no effect on the intrinsic dissolution and solubility of theophylline. This suggests that PVA and PAA are inhibiting the transformation of theophylline by affecting the growth of the hydrate phase.
The Use of Polyvinyl Alcohol and Polyacrylic Acid to Inhibit the Hydrate Transformation of the Drug Theophylline
Dr. C.C. and Mabel L. Criss Library
The solid form of active pharmaceutical ingredients (APIs) in drug tablets have the potential to transform into a hydrate state. These transformations are important to understand in order to prevent unwanted transformations when the anhydrate crystals are in the presence of water. Specific polymer excipients have the ability to inhibit this anhydrate to hydrate transformation. In this study, various properties of polyvinyl alcohol (PVA) and polyacrylic acid (PAA) were investigated to better understand the factors that inhibit this theophylline transformation. Anhydrous theophylline was added to solutions containing dissolved PVA or PAA and the transformation from anhydrate to hydrate theophylline was monitored using in-line Raman spectroscopy by collecting spectra every 30 seconds. A calibration model was used to quantify the extent of the transformation for each of the collected Raman spectra, which was then used to construct transformation profiles. The results showed that the inhibition of theophylline was dependent on chain length and percent hydrolysis of the polymer. In addition, intrinsic dissolution and solubility tests were performed to further examine the mechanism of this inhibition. These results indicate that the presence of PVA or PAA had little to no effect on the intrinsic dissolution and solubility of theophylline. This suggests that PVA and PAA are inhibiting the transformation of theophylline by affecting the growth of the hydrate phase.