Seidenader Maschinenbau, a German supplier of automatic inspection systems, has sold its first machine with integrated head space analysis (HSA) to China.
HSA is a complementary inspection technology used to check the integrity of pharmaceutical containers. For the Chinese customer, head space analysis has been integrated as a single module within a Seidenader MS series vision inspection machine.
Leak tightness of pharmaceutical containers is one of the most important safety criteria for parenterals and with HSA pharmaceutical manufacturers have their products checked inline and with a non-destructive test, by verifying the pressure in the headspace of containers.
Parenteral products are also usually filled under partial vacuum; in other cases an inert filling gas is added. The HSA gives information about the absolute pressure as well as the water partial pressure within the container and, after comparison with the appropriate set values, about its leak tightness. Depending on the handling system and head space gas characteristics, up to 600 vials/min and 100 measurements for each container can be analysed.
The challenge of the Chinese project was the small size of the containers and the limited space for the additional leak test module
Seidenader says the challenge of the Chinese project was the small size of the containers and the limited space for the additional leak test module on the MS inspection platform. 2R vials filled with lyophilised product are inspected for particles and cosmetic defects by several camera stations at a speed of 400 vials/min. The Seidenader solution for a complete HSA leak test has been implemented in one small module that is installed in an available spare position of the vision inspection carousel. In addition to the measurement path, this module contains a reference path to compensate for ambient air influences in the measurement path.
The precisely positioned vials pass the laser head. The laser beam, tuned over a certain wavelength range, is sent through the headspace of the vial. A photo-sensor receives the transmitted light. After balancing this signal by means of the reference signal, the absorption profile of the headspace gas is determined. The analysis of this profile results in precise information about the absolute pressure and water partial pressure if required. The obtained data are compared with threshold values to generate pass/fail decisions. The PLC tracks each product and activates the reject gate to separate defective from good products.
