Near-Infrared Assay and Content Uniformity of Tablets - Pharmaceutical Technology

Latest Issue

Latest Issue
PharmTech Europe

Near-Infrared Assay and Content Uniformity of Tablets
Near-infrared (NIR) assay and content uniformity of tablets provide fast, accurate means of monitoring tablet production that are in step with FDA's process analytical technology initiative.The authors discuss the process for testing a newly released NIR tablet analyzer to determine instrument precision and accuracy using chlorpheniramine maleate tablets.The data show promising results that could relieve laboratory workload of high-performance liquid chromatography analysis and bring analysis closer to..

Pharmaceutical Technology

Figure 5
The NIR instrument used in the study was XDS MasterLab (FOSS NIRSystems, Laurel, MD), which was capable of automatically measuring multiple tablets after they were positioned in a special tray (see Figure 1). In the insert, a tablet tray is to the left, and to the right is the standards tray containing the wavelength standard (traceable to NIST SRM-2035) for photometric standards. The universal tablet tray used for this study had 20 positions for four different tablet sizes and five positions for the 0.25-in. diameter tablets under test. The tray was loaded twice to scan all 10 tablets. The 10 tablets were scanned in less than 5 min, taking a reference spectrum before scanning each set of five tablets. Spectra were collected in the transmission mode from 800 nm to 1650 nm with 0.5-nm data intervals, and 32 scans were coadded to produce a single spectrum. HPLC analysis was run on each individual calibration and validation tablet after spectra were collected with the NIR instrument. The HPLC reference values and the NIR spectra were used to develop the regression model.


Figure 6
Figure 2 shows the raw NIR spectra from the calibration set and a spectrum of pure CPM in green. The pure CPM spectrum was scanned in reflectance and multiplied by a scaling factor to superimpose it over the transmission calibration spectra. By taking the second derivative of the spectra, as shown in Figure 3, the baseline was normalized and the spectral features were enhanced so that the fanning out of the analytical region for CPM was observed at 1138 nm. Figure 4 shows the expanded analytical band demonstrating the linear response from 0.1 mg to 2.0 mg CPM. Smoothing was done on the derivative with a segment of 10 and a gap of zero. A thickness correction was applied as a math pretreatment to correct for tablet thickness and density variance over the region of 1250–1350 nm. The raw spectral variance of the calibration set is large over this region, and the pure CPM has an absorption minimum as seen in Figure 2. Thickness correction is a normalization function offered in Vision software (Foss NIRSystems, Inc.) as a spectral mathematical pretreatment used to correct for path length variance. The integral correction factor was calculated over the range of 1250–1350 nm with a unity-scaling factor.

Integral correction factor =

Figure 8
The correction factor equals the 0.5-nm increment at which the data were collected times the sum of the y-axis values (S'i) and the y-axis value plus 1 (S'i+1), divided by 2. Then, the original spectrum was divided by this correction factor throughout the analytical region of 1120–1380 nm.


blog comments powered by Disqus
LCGC E-mail Newsletters

Subscribe: Click to learn more about the newsletter
| Weekly
| Monthly
| Weekly

What role should the US government play in the current Ebola outbreak?
Finance development of drugs to treat/prevent disease.
Oversee medical treatment of patients in the US.
Provide treatment for patients globally.
All of the above.
No government involvement in patient treatment or drug development.
Finance development of drugs to treat/prevent disease.
Oversee medical treatment of patients in the US.
Provide treatment for patients globally.
All of the above.
No government involvement in patient treatment or drug development.
Jim Miller Outsourcing Outlook Jim MillerOutside Looking In
Cynthia Challener, PhD Ingredients Insider Cynthia ChallenerAdvances in Large-Scale Heterocyclic Synthesis
Jill Wechsler Regulatory Watch Jill Wechsler New Era for Generic Drugs
Sean Milmo European Regulatory WatchSean MilmoTackling Drug Shortages
New Congress to Tackle Health Reform, Biomedical Innovation, Tax Policy
Combination Products Challenge Biopharma Manufacturers
Seven Steps to Solving Tabletting and Tooling ProblemsStep 1: Clean
Legislators Urge Added Incentives for Ebola Drug Development
FDA Reorganization to Promote Drug Quality
Source: Pharmaceutical Technology,
Click here