Taking in Oxygen Tests

Modified atmosphere packaging (MAP) or gas flushing is intriguing medical packaging professionals these days given its potential applications for drug-device combination products and biologics, reports Ed Emerson, business development for Mocon Inc. (Minneapolis). “MAP may help extend shelf life and preserve product efficacy.”

Process validation involves measuring package oxygen levels, and test systems up to this point have relied upon invasive headspace analysis. “Typical headspace gas tests involve a needle piercing the package to sample the headspace,” says Emerson. “The needle can be a challenge to use with small packages—you need at least 5 ml of headspace gas sample. And there is always the risk of an accidental needle stick.”

OpTech - O2 Platinum can measure oxygen down to 10 parts per million.

Addressing these challenges, Mocon has developed a new system called OpTech – O₂ Platinum, which uses optical fluorescence technology and small platinum dots placed into packages. As a light source is shined on the dot, it reflects or fluoresces proportionately to the amount of oxygen present, down to 10 parts per million.

The OpTech – O₂ Platinum also has a platinum-tipped probe that can be inserted into the package. “This capability requires zero headspace, and it can also read dissolved oxygen in liquid products,” adds Emerson.

One advantage of this nondestructive method is this headspace measurement can be taken without opening the sealed package. Using dots or probes, the permeation, leakage, headspace, and dissolved oxygen analysis determination in flexible and rigid packaging can all be performed. While the method can be used for research testing, FDA has not approved a drug or medical device package with a dot remaining inside.

The Pac Check Model 450 EC can measure oxygen concentration in small blisters as well as large pouches.

Says Doug Lindemann, vice president, Mocon: “Companies could send packages with platinum dots through MAP lines and sample them off-line to validate line processes. It can also be used in conjunction with accelerated aging studies as well as distribution testing.”

At Pack Expo International, Mocon introduced Pac Check Model 450 EC benchtop unit for analyzing the oxygen in bottle and pouch headspace. “Cumbersome calibration has been the trouble with headspace analyzers in the past,” says Lindemann. “Companies have often failed to properly calibrate and ended up performing headspace analysis incorrectly.”

The Pac Check Model 450 EC offers two-point calibration and simplified menu structure that allows users to go from set-up to test in less than a minute, making it extremely fast and easy to operate. It can measure an O₂ concentration range from 0 to 100% in package types ranging from small blisters to large pouches.

Mocon has also introduced OxyTraQ for rapid oxygen-transmission rate testing of rigid packages. The six-station, six-sensor system has an optional off-line “purge-rack,” which optimizes sample conditioning and throughput. When packages reach equilibrium they can be moved to the sensor for final readings, says Lindemann.

Mocon has entered into an agreement with Plastic Technologies Inc. (PTI; Holland, OH) for the manufacturing and global marketing of the OxyTraQ.