Laboratory automation within the pharmaceutical industry has been expanding rapidly over the past decade, providing higher productivity, precision, and quality. By reducing the number of repetitive manual tasks and thus the risk for potential error, time can be saved, allowing the scientist to concentrate on research. Many companies have invested in automated systems, ranging from liquid handling for tube and plate set-up to high-content screening assays and analytical equipment. Such equipment can be used for the analysis of intermediate synthesis stages during the drug discovery process, in addition to final analysis and quality control.
Despite extensive automation however, the process of equipment maintenance still relies on manual input. Users of analytical instruments, such as high-performance liquid chromatography (HPLC) or mass spectrometers (MS), need to constantly monitor solvent levels in supply and waste vessels. Failure to do so can result in damage to expensive equipment and unwanted down time and cost. There is also the potential threat of leakage of potentially dangerous solvents if waste levels overflow.
Visual monitoring of solvent levels in supply and waste vessels can be problematic as they are often placed behind instruments, below benches, or in fume cupboards, and trays can contain multiple bottles. In addition, due to the volatility of such solvents, they are often stored in dark glass bottles to avoid photo-reactivity, which does make it harder to visually assess levels.
Although it is often possible to set analytical instrumentation to estimate solvent usage, this depends on users accurately setting the starting levels and resetting the system each time a bottle is replaced, a problem in a multi-user environment. Instead, devices such as weighing scales and dip tubes are often employed; however, these are not ideal. Weighing cells need taring after every bottle change and it is not practical to fit six weigh cells in an HPLC/UPLC/MS drip tray due to their size. Dip tubes are useful, but being placed within solvent bottles they are often responsible for the contamination of supply solvent. Careful cleaning is needed to remove any solvent or bacterial growth and tubes must be resistant to the solvent itself to ensure they do not cause a reaction, which could also lead to contamination.
In order to be able to provide a fully-automated workflow, the process of solvent monitoring also needs to be reliably automated. As a noncontact monitoring system for the noninvasive monitoring of solvent levels, aequus from TTP Labtech enables the streamlining of advanced protocols. The easy-to-fit sensors can be attached to bottles by Velcro straps and solvent levels can be visualized via a bench-mounted touch screen display. The sensors accurately measure the level of liquid in a wide variety of non-conductive vessels, accurately compensating for vessel material—including glass and plastic—and wall thickness with a resolution of better than 0.5 mm.
With the ability to provide local feedback and display the solvent levels in up to 12 bottles (six supply, six waste), the risk of contamination is eliminated, as are the size and calibration constraints associated with current devices. An independent, configurable warning alarm can alert users when vessels are running low or are getting full. The ability to provide data logging enables the laboratory manager to keep track of those solvents that are used slowly or that deteriorate over time, as well as to detect potentially dangerous leaks.
Filed Under: Drug Discovery