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PT Monthly Archives: July 2020
Pharmaceutical Tablets Surface Roughness Inspection
Pharmaceutical Tablets
Inspecting Roughness using 3d profilometers
Author:
Jocelyn Esparza
Introduction
Pharmaceutical tablets are the most popular medicinal dosage used today. Each tablet is made up by a combination of active substances (the chemicals that produce pharmacological effect) and inactive substances (disintegrant, binder, lubricant, diluent – usually in the form of powder). The active and inactive substances are then compressed or molded into a solid. Then, depending on the manufacturer specifications, the tablets are either coated or uncoated.
To be effective, tablet coatings need to follow the fine contours of embossed logos or characters on tablets, they need to be stable and sturdy enough to survive handling of the tablet, and they must not cause the tablets to stick to each other during the coating process. Current tablets typically have a polysaccharide and polymer-based coating which include substances like pigments and plasticizers. The two most common types of table coatings are film coatings and sugar coating. Compared to sugar coatings, film coatings are less bulky, more durable, and are less time-consuming to prepare and apply. However, film coatings have more difficulty hiding tablet appearance.
Tablet coatings are essential for moisture protection, masking the taste of the ingredients, and making the tablets easier to swallow. More importantly, the tablet coating controls the location and the rate in which the drug is released.
MEASUREMENT OBJECTIVE
In this application, we use the NANOVEA Optical Profiler and advanced Mountains software to measure and quantify the topography of various name brand pressed pills (1 coated and 2 uncoated) to compare their surface roughness.
It is assumed that Advil (coated) will have the lowest surface roughness due to the protective coating it has.
NANOVEA
HS2000
Test Conditions
Three batches of name brand pharmaceutical pressed tablets were scanned with the Nanovea HS2000
using High-Speed Line Sensor to measure various surface roughness parameters according to ISO 25178.
Scan Area
2 x 2 mm
Lateral Scan Resolution
5 x 5 μm
Scan Time
4 sec
Samples
Results & Discussion
After scanning the tablets, a surface roughness study was conducted with the advanced Mountains analysis software to calculate the surface average, root-mean-square, and maximum height of each tablet.
The calculated values support the assumption that Advil has a lower surface roughness due to the protective coating encasing its ingredients. Tylenol shows to have the highest surface roughness out of all three measured tablets.
A 2D and 3D height map of each tablet’s surface topography was produced which show the height distributions measured. One out of the five tablets were selected to represent the height maps for each brand. These height maps make a great tool for visual detection of outlying surface features such as pits or peaks.
Conclusion
In this study, we analyzed and compared the surface roughness of three name brand pressed pharmaceutical pills: Advil, Tylenol, and Excedrin. Advil proved to have the lowest average surface roughness. This can be attributed to the presence of the orange coating incasing the drug. In contrast, both Excedrin and Tylenol lack coatings, however, their surface roughness still differ from each other. Tylenol proved to have the highest average surface roughness out of all the tablets studied.
Using the NANOVEA HS2000 with High-Speed Line Sensor, we were able to measure 5 tablets in less than 1 minute. This can prove to be useful for quality control testing of hundreds of pills in a production today.
NOW, LET'S TALK ABOUT YOUR APPLICATION
Microparticles: Compression Strength and Micro Indentation
MICROPARTICLES
COMPRESSION STRENGTH & MICRO INDENTATION
BY TESTING SALTS
Author:
Jorge Ramirez
Revised by:
Jocelyn Esparza
INTRODUCTION
Compression strength has become vital to quality control measurement in developing and improving new and existing microparticles and micro features (pillars and spheres) seen today. Microparticles have various shapes, sizes and can be developed from ceramics, glass, polymers, and metals. Uses include drug delivery, food flavor enhancement, concrete formulations among many others. Controlling the mechanical properties of microparticles or microfeatures are critical for their success and requires the ability to quantitatively characterize their mechanical integrity
IMPORTANCE OF DEPTH VERSUS LOAD COMPRESSION STRENGTH
Standard compressive measurement instruments are not capable of low loads and fail to provide adequate depth data for microparticles. By using Nano or Microindentation, the compression strength of nano or microparticles (soft or hard) can be accurately and precisely measured.
MEASUREMENT OBJECTIVE
In this application note we measure the compression strength of salt with the NANOVEA Mechanical Tester in micro indentation mode.
NANOVEA
CB500
TEST CONDITIONS
maximum force
30 N
loading rate
60 N/min
unloading rate
60 N/min
indenter type
Flat Punch
Steel | 1mm Diameter
Load vs depth curves
Results & Discussion
Height, failure force and strength for Particle 1 and Particle 2
Particle failure was determined to be the point where the initial slope of the force vs. depth curve began to noticeably decrease.This behavior shows the material has reached a yield point and is no longer able to resist the compressive forces being applied. Once the yield point is surpassed, the indentation depth begins to exponentially increase for the duration of the loading period. These behaviors can be seen in Load vs Depth Curves for both samples.
CONCLUSION
In conclusion, we have shown how the NANOVEA Mechanical Tester in micro indentation mode is a great tool for compression strength testing of microparticles. Although the particles tested are made of the same material, it is suspected that the different failure points measured in this study were likely due to pre-existent micro cracks in the particles and varying particle sizes. It should be noted that for brittle materials, acoustic emission sensors are available to measure the beginning of crack propagation during a test.
The NANOVEA Mechanical Tester offers depth displacement resolutions down to the sub nanometer level,
making it a great tool for the study of very fragile micro particles or features as well. For soft and fragile
materials, loads down to 0.1mN are possible with our nano indentation module
NOW, LET'S TALK ABOUT YOUR APPLICATION
Ball Bearings: Wear Resistance Using Macro Tribology
Dental Tools: Dimensional and Surface Roughness Analysis
