Developments in Scanning Electron Microscopy for Tablet and Granule Characterization - Pharmaceutical Technology

Latest Issue

Latest Issue
PharmTech Europe

Developments in Scanning Electron Microscopy for Tablet and Granule Characterization
Recent advances in SEM, particularly the incorporation of automation and software, have made simpler, lower-end SEM instruments easy to operate and have improved the capabilities of larger, sophisticated instruments.

Pharmaceutical Technology

To provide the resolution necessary to generate images that can be statistically analyzed, FEI had to modify its detectors. "The high energy primary electron beam causes low energy (secondary) electrons to emerge from the specimen and are then accelerate (pulled) toward the detector," says Ben Lich, strategic marketing manager of SEM and DualBeam at FEI. Using a standard secondary electron detector the particles in the image appear to be illuminated from one side only, resulting in a dark and a bright side. The company engineers created a special symmetrical secondary electron detector that eliminates this effect. "But when you do that, normally you will get a dark side of the object and a bright side of the object, with the bright side being the side facing," says Lich. "For particle detection this is not desired because you want a good impression of the outer area of the particle so you can do a precise measurement." Engineers then made a special detector that collects a secondary electron symmetrically around the column and around the primary beam, thereby providing uniform illumination of the entire specimen surface and a good definition of the edge around the entire particle.

The advances in SEM instrumentation are making it easier for tablet manufacturers looking into adding SEM instrumentation to their quality laboratories. "With a low-entry type of tool, people get exposed to electron microscopy and may then follow with a higher-end instrument," says Lich. "They find that it is not as hard as some people think it is."


1. All You Wanted to Know about Electron Microscopy (FEI Company, Hillsboro, OR).

2. D.A. Muller et al., "Atomic-Scale Chemical Imaging of Composition and Bonding by Aberration-Corrected Microscopy," Science 319 (5866), 1073–1076 (2008).

3. Advances in Optical Imaging (D0D2) and Emerging Technologies in Microscopy (D353) (Frost & Sullivan,


blog comments powered by Disqus
LCGC E-mail Newsletters

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

FDASIA was signed into law two years ago. Where has the most progress been made in implementation?
Reducing drug shortages
Breakthrough designations
Protecting the supply chain
Expedited reviews of drug submissions
More stakeholder involvement
Reducing drug shortages
Breakthrough designations
Protecting the supply chain
Expedited reviews of drug submissions
More stakeholder involvement
View Results
Eric Langerr Outsourcing Outlook Eric LangerTargeting Different Off-Shore Destinations
Cynthia Challener, PhD Ingredients Insider Cynthia ChallenerAsymmetric Synthesis Continues to Advance
Jill Wechsler Regulatory Watch Jill Wechsler Data Integrity Key to GMP Compliance
Sean Milmo European Regulatory WatchSean MilmoExtending the Scope of Pharmacovigilance Comes at a Price
From Generics to Supergenerics
CMOs and the Track-and-Trace Race: Are You Engaged Yet?
Ebola Outbreak Raises Ethical Issues
Better Comms Means a Fitter Future for Pharma, Part 2: Realizing the Benefits of Unified Communications
Better Comms Means a Fitter Future for Pharma, Part 1: Challenges and Changes
Source: Pharmaceutical Technology,
Click here