BOC Edwards Pharmaceutical Systems and Physical Sciences Inc. (PSI) have signed a joint agreement to develop tunable diode laser absorption spectroscopy (TDLAS)-based technologies for pharmaceutical processing equipment. The two companies, who have already successfully completed a pilot project with a global pharmaceutical company in the US, are incorporating TDLAS into freeze-drying equipment. The result is the first ever freeze-dryer to offer instantaneous measurements of water removal, a capability that will enable pharmaceutical companies to significantly improve product time-to-market and profitability.

“Current measurement techniques rely on a combination of pressure and/or temperature readings,” explains Bill Kessler, sensor applications manager, Physical Sciences Inc. “Using TDLAS we have been able to create a mass flux monitor that provides a direct reading. This means faster cycles – both in formulation development and production – and a reduction in the instrumentation and labour normally required to identify primary and secondary drying endpoints.”

TDLAS utilizes narrow band laser sources that generate a high-resolution infrared spectrum. It takes an optical measurement of gas (water vapor) concentration (molecules/cm3) and gas velocity (m/s) to provide a mass flux reading (concentration x velocity x duct area). Previously regarded as a specialist laboratory technique, the advent of reliable single-mode near-infrared diode lasers in the 1990s has resulted in TDLAS becoming an accepted analytical technique for a variety of process environments.

BOC Edwards Pharmaceutical Systems now plans to incorporate the technology in its freeze dryer product range to help pharmaceutical manufacturers improve process control in line with the FDA’s process analytical technology (PAT) initiative.

“This is a very exciting partnership,” comments Jan Vugts, global technical manager, BOC Edwards Pharmaceutical Systems, ”And one which will enable us to continue the successful integration of leading-edge science into our products.”