Image of the Month: Cold Season – February 2014
Have you been sick this winter and taken a cold pill to relieve your symptoms? Have you ever wondered about the science behind cold pills? We at Micro Photonics were interested and found there is a lot that goes into ensuring the quality of the pills we rely to alleviate our symptoms. There is a lot of science which goes into making a pill, from the uniform distribution of the chemical components, to the investigation of micro-cracks and pores, along with any coatings which help the pill get broken down in the optimal part of the digestive tract. Through the use of micro-CT imaging, we are going to explore the pill we take for granted while sick.
Pills (powered tablets in this case), are made from both active and inactive ingredients. The active ingredients consist of the chemical drug that is meant to relieve your symptoms and the inactive ingredients are fillers which are used to aid in pill swallowing or break down within the gastrointestinal tract3. These ingredients are homogeneously mixed and then compressed through manufacturing techniques to form the pill2. Quality checks are performed at this step, and this is where Micro-CT imaging is key.
Why Care About Chemical Component Distribution
In order to ensure that each pill provides the relief we need, it is critical that the chemical components are homogeneously distributed and sized properly throughout the tablet. This ensures the active drug is released into the blood stream at the appropriate time and in the right amount. Variations in the active components can cause the drug to be absorbed too quickly, or insufficiently. If the size or distribution is such that the pill absorbs too quickly, an overdose of the drug in the bloodstream can occur. Alternatively, if most of the active ingredients are concentrated in a specific portion and not broken down (the size of particle is too big), the ingredient may pass through the intestinal tract, leaving you feeling just as miserable3.
Using our laboratory SkyScan 1173 Micro-CT system, we scanned the pill and ran an analysis with our CTAn software to test the particle size distribution. Based on the analysis we confirmed there is a bell curve distribution of particles (Figure 3). This is ideal as the active ingredients will break down in a uniform manner (smallest particles first and larger over time) to ensure appropriate uptake into the bloodstream.
Figure 3. Distribution of Active Ingredients based on percent volume
Why Pores and Cracks Matter
Reducing the amount of cracks and pores is important because too many of them increase the risk of failure to the pill’s structural integrity. Imagine buying pills, opening the package, only to find powder because the pill fell apart. Broken or cracked pills will also absorb differently in the body as opposed to intact pills. So how do the cracks and pores form? The reason is due to a combination of the compaction process and the inactive ingredients (such as polymeric excipients) which have elastic properties2. After compaction, the polymeric excipients expand the volume of the pill, which can lead to internal micro-cracking2. Trapped air within the pills is also concerning because they create possible failure points both during compaction and when the pill is exposed to additional manufacturing processes, such as packaging.
Micro-CT imaging can be used to identify the problematic internal cracks and pores. With the help of the DataViewer software, orthographic images were created to demonstrate the identification of cracks and pores throughout the pill (Figure 4).
Figure 4. Identification of cracks (A) and pores (B) with the DataViewer software
We hope you enjoyed learning about Micro-CT imaging and its association with the pharmaceutical industry. If you have an interesting industrial application performed with a Micro-CT and would like it showcased as the next image of the month, feel free to e-mail: firstname.lastname@example.org. We would love to include your work.
1. Faitsch L, Gopinathan N, Santiago A, Wardrop J. An Investigation into the effect of wall friction during polymer compaction. Manufacturing Science and Technology, Global Pharmaceutical Operations, Abbott. [cited 2015 February 26].
2. Kemp CAJ, Schrad MA, Sloan JT, Hilden JL. Quantifying Agglomerates in Pharmaceutical Powder Blends using X ray micro CT. Eli Lilly and Company, Lilly Research Laboratories, Lilly Corporate Center. [cited 2015 February 27].
3. Le, J. 2014. Drug Absorption. Whitehorse Station (NJ): Merck Sharp & Dohme Corp; [cited 2015 February 26]. Administration and kinetics of drugs. Available from:http://www.merckmanuals.com/home/drugs/administration-and-kinetics-of-drugs/drug-administration