At-Line Processing Monitoring
“The industry is looking for tests that measure drug quality,” revealing their structure, Galliher continues. That type of process analytic technology was first used for pharmaceuticals in the development phase. The few such tools for the manufacturing phase tend to be in the early stages of development.
The challenge is more than merely adapting existing technology to an in-line, real-time environment. In biological manufacturing there are very few sensors that tell you what’s going on with the molecule of interest, Galliher points out. Instead, “the industry relies upon parametric sensors—pH, UV, conductivity, etc.—that measure the environment in which you’re making the drug. That’s like walking down a path blindfolded.
“At Xcellerex, we’re actively engaged in online, real-time sensor development, looking at quality and quantity,” Galliher says. “We’re past proof-of-concept and are hardening the sensors in a development setting. The trick is analyzing drug quality and quantity early on, when the drug isn’t very pure.” This ensures the assay analyzes the drug and is not confounded by background contaminants, he explains.
To do this, Xcellerex is exploring many software algorithms and is looking at molecules in different ways and many times to generate a more complete analysis than is possible with the current snapshot-in-time analytic approach.
Millipore is one of a few companies developing at-line process monitoring equipment approximating real-time speeds. The firm’s method is based upon nucleic acid technology, developed in collaboration with Gen-Probe, explains Jean-Paul Mangeolle, president of the bioprocess division of Millipore. It is being designed for microbial contamination in raw materials, in-process samples, and final products.
The technology, called MilliPROBE™, uses Gen-Probe’s target capture methodologies and real-time transcription-mediated amplification to concentrate, amplify, and purify ribosomal RNA (rRNA) without culturing. Consequently, very low levels of contamination can be identified in samples. The first product, released last January, provides an early-warning system to detect Pseudomonas aeruginosa in purified water used in drug manufacturing processes.
MilliPROBE can be used within the quality control lab, although the goal is to optimize it for the manufacturing floor and ultimately deliver in-line process monitoring and control technology. The platform identifies contaminants within a few hours, offering a vast improvement over the three to five days required by traditional culture methods. Validation data showed a sensitivity of approximately 10,000 copies of P. aeruginosa rRNA and greater than 98% detection of actual microbial cells. The assay’s detection limit is below 10 cells per 100 mL of sample.
“When you try to do nucleic acid testing, you’re getting very low concentrations of contaminants,” Mangeolle points out. “Therefore, overcoming background contamination is a challenge. You must move to closed systems that offer no risk of outside contamination.
“To be fast, you have to eliminate the culture step. So 100 to 200 mL are filtered through a membrane, the contaminants are lysed using chemicals or other methods, rinsed, and assayed to measure the nucleic acid.”
Eventually, the MilliPROBE system is expected to replace an important segment of Millipore’s process-monitoring business as the industry moves from growth-based technology to more modern culture-free products, Mangeolle notes.
Celsis International is developing a quick speciation test that within 24 hours identifies the type of contamination problem a product is facing, according to Jennifer Havill, product manager. This nucleic acid-based assay is being designed to overcome “many of the problems of current RNA methods, such as tightly controlled temperature requirements and dangers of contamination.”
Currently, Celsis is working with consumer products and pharma manufacturers to help them convert from RapidScreen to AkuScreen. Both technologies are based on ATP bioluminescence. RapidScreen detects microbial contamination between 24 and 48 hours. AkuScreen is even faster, detecting even minute levels of mold between 18 and 24 hours.
Return on investment typically occurs within six to eight months, Havill reports. “Companies using AkuScreen can release their products to market six to fourteen hours faster than before and several days earlier than traditional methods. That translates into an average of $500,000 net present value.”