Related Experiment Video
Updated: Sep 23, 2025

Comprehensive Compositional Analysis of Plant Cell Walls Lignocellulosic biomass Part II: Carbohydrates
Published on: March 12, 2010
Quantitative chemical profiling of cellulose acetate excipient via 13C NMR spectroscopy in controlled release
Isha Saraf1, Varun Kushwah1, Lourdes Contreras2
1Research Center Pharmaceutical Engineering (RCPE) GmbH, Inffeldgasse 13, 8010 Graz, Austria.
Abstract:
Cellulose acetate (CA) is the main component of controlled-release (CR) coating of formulations such as osmotic-controlled release oral delivery system (OROS) and CR microspheres. Despite multiple applications, there are limited or no reports dealing with the characterization and quantification of CA in the formulated systems. Thus, the present investigation deals with the development of the Quantitative Carbon-13 Nuclear Magnetic Resonance (q13CNMR) spectroscopy method for the determination of CA amount in the CR microsphere formulations. The developed q13CNMR method was also verified using control CA samples from marketed OROS formulation. Thereafter, the concentration of CA in the microspheres was calculated. Furthermore, the impact of different concentrations of CA on the critical quality attributes such as the drug release profile from the formulation was investigated. The study demonstrated the CA coating levels to be inversely proportional to the extent and rate of release of API. The developed q13CNMR method was found to be accurate and precise and can be explored further to investigate the effect of different stability conditions on the degree of polymerization and degradation of CA resulting in altered quality of pharmaceutical products.
More Related Videos
Related Concept Videos
¹H NMR Signal Integration: Overview
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
NMR and Mass Spectroscopy of Carboxylic Acids
While α protons of carboxylic acids absorb at 2–2.5 ppm, β protons absorb further upfield.
Carboxylic acids are easily identified by dissolving them in deuterium oxide, which results in a rapid exchange of the acidic protons with deuterium. This leads to the...
Spectroscopy of Carboxylic Acid Derivatives
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones

