What are some “must-have” features that pharma companies are looking for when evaluating HPLC equipment?
David Elder: Reliability, flexibility and cost are three very important variables. Reliability, from the perspective that a customer can use the same instrument right across the globe over a 10 year life cycle (based on 10% depreciation costs/annum). Flexibility, that allows the customer to purchase (as required) new ‘aligned modules’ to react to new business drivers. These modules can be added to the core instrument without impacting on the overall system’s performance. For instance, if there is need for greater throughput then the customer could add a UPLC pump module and use sub-2 micron, core shell or monolithic column technologies to run fast LC. So HPLC/UPLC will be better aligned in the future and not necessarily separate. A larger volume refrigerated autosampler may also be required to run greater sample volumes. Cost to allow companies to run more efficient operations. Cost of consumables needs to be driven down.
Diane Diehl: Reproducible, biocompatible, ability to run existing or “legacy methods”, but also run UHPLC methods.
Chunang (Christine) Gu, PhD: During the past 30 years, HPLC became undoubtedly the well-adopted analytical instrument for identification and quantification of compounds of interest in the process of drug discovery, development and manufacturing. No matter in what stage of drug development, the most important feature is the robustness of the HPLC system. Customers are not only interested in the innovative, high-tech instrument, but mainly need real-time reliability of both software and hardware to make trouble-free HPLC equipment. In the meanwhile, the HPLC equipment needs to be easy to use. Chemists have less and less “down time” to obtain the training to operate a HPLC system. Overall, a simple, efficient, reliable and idiot-proof HPLC system is a “dream machine” in the analytical labs.
Jeff Reid: HPLC is used for a variety of applications pertaining to pharma-ceutical drug analysis and monitoring, along with the quality assur-ance of the final pharmaceutical product. By the utilization of HPLC pharmaceutical chemists are able to identify and quantify individual compounds from a complex mixture. These chemists are challenged by analyzing complex mixtures at very low concentrations. Therefore, a must-have feature for detectors is high sensitivity with low detection limits.
Another must-have feature for HPLC in the pharmaceutical industry is automation. Automation not only increases sample throughput but it also helps with the accuracy of the data by eliminating human error. Features such as automatic samplers and injectors are absolutely necessary so a pharmaceutical lab can maximize its productivity and produce accurate and reproducible results.
Lastly, the pump is another critical component to consider for HPLC. The must-have feature for a pump is easy programming and a wide flow rate range. Also, it must be manufactured from robust materials so it can withstand several different applications. The material in contact should be stainless steel, titanium, ruby, PEEK, or PTFE to ensure a long lifetime. An automatic seal washing function is also good to have as it helps reduce operation costs. This is particularly important when working with high salt mobile phases.
Are HPLC’s moving toward a “universal” detector model? Are there pros and/or cons to this approach?
Elder: I think the jury is still out on this question! UV still continues to be the workhorse detection mode for HPLC. Although MS still has many advocates it is still a challenge to understand from first principles what the ionization efficiency of a new analyte is likely to be and it struggles to deliver the requisite precision. Similarly, although CAD (corona charged aerosol detector) and other similar aerosol detectors have the promise of universality, the responses typically aren’t linear making quantitative assessments difficult. In many ways, indirect UV/ visible detection is a very practical approach, utilizing all the perceived advantages of the UV/visible detector, yet still being able to detect non-chromophoric analytes. However, its biggest failing is poor sensitivity. The increased utility of several detectors in series, (e.g., UV, RI and aerosol-based detectors), will likely increase in the future, which again speaks to the need for a modular, flexible approach.
Diehl: In an ideal laboratory setting, having an LC with one detector that sees every type of molecule is highly desired. This reduces the amount of detectors or even techniques required. In reality, we are not quite there yet with a detector that can cover the entire chemical space – especially from small molecules through peptides and mAb’s. But, many vendors are working towards that end.
Gu: HPLC itself is not a detector; however, it can be coupled with different types of detectors, such as UV, CAD, ELSD, MS, to analyze various classes of compounds and meet appropriate sensitivity requirement at different drug development stages. In addition, new developments of HPLC systems and the column technology makes HPLC more attractive in pharmaceutical applications.
First and foremost is the growth of ultra high-pressure liquid chromatography (UHPLC) for more efficient separation in the industry. There is also a continuing trend in developing new packing and stationary materials for HPLC columns, such as hydrophilic interaction chromatography (HILIC), newer bonded phases (mixed mode, charged surface hybrids). For example, amino acid analysis has mainly been carried out by gas chromatography (GC). Recently HILIC has become one of the successful approaches to the retention and separation of polar compounds, and has been widely used for amino acid analysis. However, the HILIC method has shown less accurate results and the longest analysis time when compared to traditional GC method.
Is it important to pharma companies for HPLC vendors to offer data collection and analysis software with their equipment?
Elder: The problems posed by ever more sophisticated software for HPLC equipment is similar to the mobile phone conundrum: how much of that capability is actually required or used? From a big pharma perspective, we typically have the HPLC system, a chromatography data station (CDS), electronic note books (eNBs), and a LIMs (Laboratory Information Management) system. The customer also then has the interface problem between those different modules. Many of these modules are difficult to interface with one another and the various vendors are reluctant to facilitate this interface because of intellectual property considerations. When these modules are eventually interfaced the entire assembly needs to be appropriately validated as per cGMP (current Good Manufacturing Practice). In addition, regulators are seeking to assure themselves that data integrity isn’t compromised and data can’t be changed, over-written or modified in any way. So in many ways it would be better if HPLC vendors offered data collection and analysis software as an addon that can be purchased separately. That way, small companies/ academic institutions that need and require this level of sophistication can obtain this, but the big customers have the flexibility of just purchasing what they need.
Diehl: Yes, absolutely. With increased focus on regulatory compliance, offering a complete package of hardware and software that can be qualified is highly desired.
Gu: There is a growing trend in pharma to develop neutral software to handle the analytical data, including HPLC data, between multiplevendor instruments and applications. For example, the project of Allotrope Foundation is designed to build an open framework for laboratory data. So far twelve big pharma companies and most vendors have joined together in making efforts to move this project forward. It is not surprising to see that this open, publically available framework will be well adopted for the analytical laboratory in the near future. In addition, software from vendors for the unique features of their own instruments is still attractive to the end users. It gives advanced customers the flexibility to make the instruments use even more intensive.
Are pharma companies interested in ongoing service and support and possibly upgrades to their systems? Is making a “future-proof “ HPLC system possible and practical?
Elder: In reality many companies already operate a future proof system. There is a greater tendency to use a single preferred supplier across the whole of R&D and production. These ‘economies of scale’ allow better service and support than was historically available. With respect to upgrading the existing system this is in principle doable if the various parts of the modular HPLC system continue to talk to each other with minimum disruption. For instance, if the customer required more sensitivity for an ongoing program and a fluorescence detector could be added to the system either in parallel or in place of the existing UV detector, with minimal disruption that would be attractive. But upgrades for new data collection and analysis software or planned obsolescence of existing software would be viewed negatively by most customers. Increased flexibility with decreased complexity are the watch words.
Diehl: Yes, service and support continue to be a deciding factor in which vendor to select. Vendors who can serve as true partners from sale to install and qualification to ongoing system support are highly desired. Yes, it is possible and practical to have a “future-proof” system, a system that can bridge from current legacy methods to future UHPLC methods. For example, Waters introduced the ACQUITY ARC system to serve that specific need. With a turn of a valve, the system can run as an HPLC or UPLC – it’s like getting two systems for the price of one.
Gu: Excellent customer service and support are not only important to the pharma companies, but also to the vendors. Sometimes it is the best way to differentiate a vendor from its competitors. A good reputation for support is more likely to get repeat business from the customers.
With the development of new column technology, most notably accomplished through the use of superficially porous particle stationary phases, the future-proof HPLC is becoming feasible. It has the ability to transfer or migrate the regular separation to UHPLC for fast analysis time and more efficient separation.
What do you foresee as some future features/ technologies that will be added to HPLC systems in the next five years?
Elder: Although faster run times are still an attractive proposition, the bottle neck still remains sample preparation. In the future there will probably be less instruments (fast LC giving shorter methods and necessitating larger autosamplers). This in turn is predicated on greater reliability and flexibility.
Diehl: There are three areas of focus: Detection, Sample Preparation and “Ease of Use”. We have already seen a move towards adding routine mass detection to LC systems and we see that movement continuing, potentially with added functionality or combinations of techniques in one unit. There is still a need to develop faster or automated processing of samples before they are introduced to the LC. There are many robots available, but nothing completed integrated with the LC. Finally, end users want LC systems to be as easy to use as an iPad – simply turn on and start running samples – combinations of software and hardware will begin to address these requirements.
Gu: In the past ten years the advent of UHPLC provides a practical leap forward to improved capability in run time, selectivity, and detection. This movement has extended UHPLC into more wide applications in industry. It also challenged the traditional HPLC platform to optimize their methods to deliver near UHPLC efficiency when possible, for example the development of solid-core particle technology.
With the increased complexity of sample mixtures during drug development, multidimensional chromatography separations are one of the most promising and powerful methods in the analytical labs. It combines extraordinary resolution and peak capacity with flexibility and overcomes the limitations of any given single chromatographic method.
Reid: The detector and column technology will be the two components that will go through the most advances over the next five years. Pharmaceutical samples are becoming more complex over time which will encourage chromatography vendors to engineer and manufacture detectors with lower detection limits. This is a common case of “purpose-built solutions”, meaning chromatography vendors will design and develop detectors around customer’s requirements.
When it comes to the column technology, we will see more new phases being developed for niche applications. For a long time HPLC columns were only made from alumina and silica. Now, there are several types of stationary phases made from unique materials such as carbons and titania. Over time this will continue to grow and suffice a broader range of pharmaceutical applications. Also, the ability to pack smaller particles with a fused core will become more prevalent over time. Submicron particle sizes with a fused core have become extremely popular over the past decade and will continue to grow as we are finding it generates a much higher efficiency than normal with improved resolution and lower detection limits. This kind of technology has become paramount in the success of pharmaceutical chemists.