Analysing packaging materials using integrating spheres

Light resistant packaging materials are commonly used to provide protection against potential harmful effects, so testing their efficacy is crucial to consumer safety. Here's how we test that materials meet the requirements for spectral transmission measurements.

The challenge


Light resistant containers and packaging materials are commonly used to provide protection of the photosensitive medicaments from harmful effects of light. This is due to fact that the absorption of light may induce the photodegradation of the active ingredients of pharmaceuticals or change the taste and appearance of food products.


The European and United States Pharmacopoeias and Food and Drug Administration require testing to ensure the suitability of these materials to maintain the efficacy of the product.

Our approach


To access the optical quality and measure the amount of light that passes through the packaging material, the transmittance characteristics of the sample must be evaluated. The development of new and more stable UV absorbers and their incorporation into polymers allows a greater stability of the plastics used for packaging systems (bottles, bags, blister packs, and cartridges).  Their role is to protect both the plastics and the products from photodegradation.


At RSSL, with the use of photostability chambers and accelerated degradation in combination with a state-of-the-art UV-Vis spectrophotometer we fitted with an integrating sphere, we evaluate the stability of UV absorbers in plastics over time. We confirm that any packaging system, offered as a light resistant container, meets the requirements for spectral transmission measurements.

Our high-performance spectrophotometer equipped with an integrating sphere (150 mm, 0°/8°), produces accurate and reliable measurements of transmittance and reflectance. Furthermore, this technique is used to evaluate the clarity of transparent packaging systems, by measuring their haziness. Finally, colour, whiteness and yellowness measurements of opaque, transparent, and translucent materials are performed to ensure that product characteristics correspond to the customer and market standards, both in the pharmaceutical and food industries.


Translucent materials, such as colored glass, plastic bags and thin films scatter light in random directions and this phenomenon is called diffuse transmission. Spectral transmission measurements are taken by means of a UV-Vis spectrophotometer equipped with an integrating sphere. The integrating sphere collects all the light which has passed through the sample integrating the radiant flux, leading to high precision transmission measurements.



In conclusion, by combining our extensive knowledge and experience in packaging material analysis with our high-performance UV-Vis spectrophotometer, equipped with an integrating sphere, we offer a comprehensive suitability study of primary and secondary packaging materials for our customers in both pharmaceutical and food industries.


Ensure the integrity of your pharmaceutical packaging


From routine pharmacopeial testing to extractables and leachables studies, RSSL can provide a full suite of analytical testing services for primary packaging. Find out more here

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