The company's oldest product line, first marketed in 2006, consists of single-use pressure sensors. "The sales line has increased year-on-year since then. The need to measure pressure is ubiquitous in bioprocessing," notes Annarelli. Applications include multi-stage depth filtration, TFF/crossflow filtration and bioreactor pressure monitoring.
PendoTECH's second single-use sensor, launched within the last year, is a temperature sensor that reportedly is attracting a lot of attention from bioprocessors.
The company already offers single-use rotary flow meters and non-disposable Coriolis flow meters, but now is developing a single-use Coriolis flow meter that it hopes to have on the market by the end of the year. "There is a lot of demand from biopharma companies for mass flow measurement, not least because there is a lot of viscosity change to products during purification processes, which does not impact the Coriolis measurement. The ability to measure at low flows is also very important: the Coriolis flow meter is accurate down to a few mL/min — making it ideal for lab-scale trials," explains Annarelli.
The firm's new single-use inline flow-through UV absorbance cell for chromatography is generating a lot of interest, he says. In bioprocess operations the UV absorbance of a liquid solution can identify the absence or presence of a molecule of interest. The measurement, typically at 280 nm, is made by a spectrophotometer. An inline cell allows for real-time process decisions.
"We also have an inline turbidity cell, which is not strictly single use, but priced ($150) in a way that it could be used as such. Turbidity is important in filtration processes: when filters start to plug, particles can sometimes pass through even before pressure builds up on the filter. A turbidity cell can detect this. It can also be important in initial centrifugation stages: if solids are passing on from this stage, the centrifugation process is not optimized," adds Annarelli.
In addition, the company is grooming a single-use conductivity cell, which should be ready by the end of the year.
"We see even bigger opportunities in the future as the industry moves towards smaller-scale, individually tailored medicines… This is also being reinforced by governments' demands that drug companies show that their products really do work by requiring more diagnostic testing, etc., before therapies are approved."
The company wants to be a full-service supplier of single-use sensing technology to the biopharma industry. "We find partners who have sensing technologies that we can take to our own industry. Right now, however, single-use pH sensing over a wide range of pHs is something we simply cannot do," Annarelli notes.
GE currently is focusing much of its effort on developing passive multivariable radiofrequency identification (RFID) sensors (Figure 2) for single-use biopharmaceutical manufacturing components such as buffer bags, connectors and bioreactors, says Radislav A. Potyrailo, principal scientist, chemistry and chemical engineering, at the company's Global Research Center, Niskayuna, N.Y.
"Typical existing sensors have one output per sensor, but if there are other parameters that affect the same sensor you are unable to find out exactly what is going on. Having several outputs, multivariable sensors can avoid this," he explains.
Portyrailo and his colleagues have been working on a technique that does away with costly proprietary RFID memory chips and their analog inputs in favor of passive 13.56-MHz RFID tags. These operate as inductively coupled sensors with 16-bit resolution provided by a sensor reader. "We have developed RFID sensors for the measurements of several critical manufacturing parameters such as pH, solution conductivity, temperature and pressure," he notes.