Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
  • Applied Spectroscopy
  • Vol. 61,
  • Issue 12,
  • pp. 1265-1274
  • (2007)

Investigating Dehydration from Compacts Using Terahertz Pulsed, Raman, and Near-Infrared Spectroscopy

Not Accessible

Your library or personal account may give you access

Abstract

The purpose of this study was to investigate the dehydration of piroxicam monohydrate (PRXMH) in compacts using terahertz pulsed spectroscopy (TPS), Raman spectroscopy, and reflectance near-infrared (NIR) spectroscopy. Compacts were prepared by using PRXMH and poly(tetrafluoro)ethylene powders and combining them in three different manners before compression to produce compacts in which the PRXMH was dispersed throughout the compact, deposited on one face of the compact, or included as a layer within the compact. TPS was a suitable technique to assess the effect of sample preparation on dehydration, whereas Raman and NIR spectroscopy were limited by their sampling depth and the interference of the polymer matrix. TPS revealed that the dehydration behavior depended largely on the compact preparation method. Non-isothermal dehydration was investigated with all three spectroscopic techniques, combined with principal component analysis (PCA) on samples where the PRXMH was deposited on one face of the compact. In addition, variable temperature X-ray powder diffractometry (VT-XRPD) was used to verify the transformation from PRXMH to anhydrous PRX form I, while thermogravimetric analysis (TGA) was used to monitor the water loss. All three spectroscopic techniques allowed in situ monitoring of the dehydration from the surface layers of the compacts. TPS and Raman spectroscopy detected structural changes of the crystal, while NIR spectroscopy was more sensitive to water loss. PCA of the TPS, Raman spectroscopy, and XRPD data revealed similar dehydration profiles. In contrast, the NIR spectroscopy profile was more similar to the TGA results. The spectroscopic techniques were more suitable than slower techniques such as VT-XRPD for monitoring rapid structural changes that occurred during the dehydration.

PDF Article
More Like This
Coherent infrared spectroscopy system from terahertz to near infrared using air plasma produced by 10-fs pulses

Eiichi Matsubara, Masaya Nagai, and Masaaki Ashida
J. Opt. Soc. Am. B 30(6) 1627-1630 (2013)

Near-infrared Raman spectroscopy of single optically trapped biological cells

Changan Xie, Mumtaz A. Dinno, and Yong-qing Li
Opt. Lett. 27(4) 249-251 (2002)

Identification and investigation of the vibrational properties of crystalline and co-amorphous drugs with Raman and terahertz spectroscopy

Wei Liu, Yu Liu, Jiaoqi Huang, Zhongquan Lin, Xuancheng Pan, Xiaojun Zeng, Marc Lamy de la Chapelle, Yang Zhang, and Weiling Fu
Biomed. Opt. Express 10(8) 4290-4304 (2019)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved