Non-contact Infrared Precision for Cold Chains within Medical Filling Process

The Need of Non-contact Temperature Control in Pharmaceutical Cold Chains

Pharmaceutical products must adhere to stringent production standards, requiring precise and reliable measurement methods. Monitoring the pharmaceutical cold chain involves maintaining specific temperature conditions throughout the journey of these products from origin to destination. This process is crucial for preserving the quality, effectiveness, and safety of temperature-sensitive medications, vaccines, and biologics, which can become ineffective or harmful if exposed to improper temperatures. The Medicines and Healthcare Products Regulatory Agency (MHRA) reports that nearly one-third of critical and major deficiencies in the storage and transport of medicines relate to temperature control and monitoring, with temperature issues accounting for 30% of deficiencies, surpassing other quality management and documentation failures. This concern applies to medicines requiring low-temperature storage (cold chain products) and those that must be stored below 25 °C (temperate chain products). Temperature monitoring enables companies to identify and manage shipments affected by temperature breaches.

Conventional temperature sensors are often used to monitor the ambient temperature in which biomedical products are processed, stored, or shipped. However, infrared imaging reveals that thermal gradients can exist between a temperature sensor and a product, even when not in contact. Monitoring each pharmaceutical product individually with contact temperature sensors is impractical due to the risk of contamination and the nature of the application. Non-contact infrared temperature sensors offer a solution by accurately measuring each pharmaceutical’s true temperature without the risk of contamination.

Deviations from recommended temperature ranges can compromise the chemical composition, stability, and efficacy of temperature-sensitive medications and vaccines. For safety and quality, in this application, vaccine vials must be cooled to a maximum of 25 °C after disinfection and before the filling process. If the glass temperature exceeds 25 °C, the vaccine becomes unusable due to its thermal sensitivity. Therefore, maintaining an ambient temperature below 25 °C is essential, as any pharmaceutical product filled into a glass container that has undergone high-temperature thermal disinfection will be destroyed if not adequately cooled.

Ensuring Pharmaceutical Safety and Quality by Infrared Monitoring Temperature-Sensitive Medical Goods

In summary, infrared cameras can provide critical temperature information necessary to insure the safe processing of pharmaceutical products. Pharmaceutical companies can follow some basic guidelines in order to properly implement remote infrared temperature measurement in their manufacturing process. First, understand if the material to be measured efficiently emits its infrared radiation (emissivity). In this application example, the empty glass vessel was over 6 times deeper than the opening at the top of the vessel creating the perfect “cavity bounce effect” that greatly enhanced the emissivity of the interior of the vessel. A measurement on the outer surface of the glass vial could yield an error because the temperature measured by the remote IR device could be influenced by an adjacent heat source. In this case, a different wavelength sensor would be recommended that is optimized for measurement on glass surfaces. Metal caps or aluminized peel-off seals are highly reflective (poor emissivity) and will essentially reflect the background temperature. It is also important to understand the spot size limitations of any infrared device when measuring small targets or small openings. Some single spot sensors would not be capable of accurate measurements of the inside of the glass vial because the spot size limitation of the sensor would be larger than the diameter of the vial. Fortunately, infrared cameras produce images from thousands of infrared pixels enabling measurement of very small areas. Make sure to use the optics calculator (link here) that takes into consideration IR camera optics, the camera resolving power and the the distance from the target. Finally, make sure to understand how the thermal dynamics of the manufacturing process can impart temperature variations on different areas of any convenance system. Temperatures can vary depending on a wide variety of factors and a quick scan with an infrared camera can help to optimize the placement of measurement cursors that will deliver temperatures on the full range of values that vary depending on their physical location.