Hot stage optical microscopy as an analytical tool to understand solid state changes in particle Characterization

Hot stage optical microscopy as an analytical tool to understand solid state changes in particle Characterization


  • Post By : Kumar Jeetendra

  • Source: Microbioz India

  • Date: 05 May,2020

When drug crystals are heated they undergo changes that can be observed under a microscope. Characteristics that can be analyzed under a microscope include melting point, melting range, crystal nucleation, crystal growth, crystal transformations and more. For example, under a microscope it is easy to see when a solid melts or how crystals nucleate and grow when cooled. This data can then be used to obtain important information about the solid such as kinetic information about crystal growth and transformation. .
Thermal microscopy (TM), also known as hot-stage microscopy (HSM) with Particle Characterisation Software , is the combination of microscopy and thermal analysis to enable the study and physical characterization of materials as a function of temperature and time.

There are several reasons why this thermo-optical technique is quite extensively used to characterize the solid-state properties of active pharmaceutical ingredients (APIs). Among these reasons, HSM allows the observation of the most obvious property of a material, namely physical appearance. It also allows characterization of small quantities of API to rapidly obtain valuable data about its solid-state properties. This technique is also a simple and relatively inexpensive method since the instrument setup basically comprises of a heating stage with a sample holder and gaseous atmosphere control coupled with a suitable polarized-light microscope and a system that allows the capturing and measurements of observations and temperatures.

In the study of solid-state active pharmaceutical ingredients (APIs), excipients and pharmaceutically relevant polymers and lipids, various observations can be made with the help of Hot stage Microscopy with Image Analysis technology.

The main advantage of optical microscopy is that the user can observe individual particles in the sample ranging from 0.5 microns to 1000 microns. Detailed information on these particles such as individual measurements and statistical results can be generated which can be then used to draw conclusions. The Biovis PSA 2000 System from Expert Vision Labs is a complete image analysis and particle size and shape characterization solution with the powerful analysis software.
The system can be easily configured to capture images of the sample and then perform evaluation to determine a number of morphological measurements such as length, breadth, area, aspect ratio, etc. After analysis the data and results can be reported or can be archived for future.
The software allows user to select from over 60 different types of measurements that can be performed over each of the individual particles in the sample. We can also differentiate the particles into different classes based on a measurement parameter, thus making it easy to distinguish and characterize the good and bad samples in the batch. Particle analysis is not just limited to the pharmaceutical industry but is also utilized in other industries which require the study of any type of particulate matter. Thus with the growth of industries and emergence of newer markets requiring Particle Size analysis, the use of microscopic image analysis for this purpose is expanding dramatically and rightly so.

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