Sample concentration and solvent evaporation are indispensable steps in nearly every pharmaceutical laboratory workflow — from early-stage drug discovery to quality control and bioanalytical testing. Yet choosing the right evaporation method for a given application is rarely straightforward. Different compounds, sample matrices, throughput demands, and sensitivity requirements all point toward different solutions.
Organomation's 2026 Sample Concentration Survey, which gathered responses from 135 lab professionals across industries, sheds important light on how pharmaceutical and biotech labs actually approach this challenge. Freeze drying ranked as the top evaporation method specifically for pharmaceutical sample types (at 67%), followed by nitrogen blowdown (56%) and centrifugal/vacuum concentration (56%). These figures reflect the complexity of pharmaceutical workflows, where no single method dominates — and where method selection must be deliberate.
This post examines the four most relevant evaporation methods for pharmaceutical labs, how each is typically employed, and the trade-offs that come with each.
Freeze drying — or lyophilization — holds a uniquely prominent place in pharmaceutical science, and the survey data reflects that prominence. The method works by first freezing a sample and then sublimating ice under low pressure, converting it directly from solid to vapor without passing through a liquid phase. This low-temperature, low-pressure process preserves heat-sensitive compounds, proteins, biologics, and enzymes far more effectively than conventional heat-based drying methods.
In pharmaceutical labs, lyophilization is the method of choice for preserving labile injectables, vaccines, biologics, and many antibiotics. Well-known lyophilized drug products include vancomycin (an intravenous antibiotic used in bloodstream infections and meningitis) and Activase (an intravenous clot-dissolving agent used in stroke treatment) — both of which require the stability that only freeze drying can reliably provide. Biologics such as interferon alfa, antihemophilic Factor VIII, and many common vaccines are similarly dependent on lyophilization to maintain potency during storage and transport. Because freeze-dried products have a highly porous structure, they can also be reconstituted rapidly — a critical advantage for emergency vaccines and injectable biologics.
Beyond final product manufacturing, freeze drying also plays a critical analytical role. In bioanalytical workflows, it is used to concentrate biological sample fractions — particularly polar metabolites — ahead of LC-MS analysis. Its ability to achieve a high degree of dryness, owing to the porous, amorphous cake structure it produces, aids resuspension and improves downstream analytical performance.
The trade-offs are real, however. Lyophilization is time-intensive: a single batch cycle can require anywhere from several hours to several days, and in some cases up to 300 hours to complete. Vial-to-vial variation within large batches is also a known concern, depending on where vials are positioned within the lyophilization chamber. The Organomation survey confirmed that pharmaceutical freeze dryer users most commonly cite maintenance demands (67%), time requirements (50%), and limited capacity (50%) as their top frustrations — underscoring that even the gold-standard method carries meaningful operational burdens.
For pharmaceutical labs working with highly sensitivebiological materials, or producing stable dosage forms that must withstand long-term storage and global distribution, freeze drying remains irreplaceable.
While freeze drying dominates pharmaceutical-specific sample type rankings, nitrogen blowdown is the most widely used evaporation method across all industries surveyed — employed by 66% of all respondents. In pharmaceutical labs, it is a mainstay of daily analytical sample preparation, particularly for workflows involving solid-phase extraction (SPE), chromatography, and mass spectrometry.
The technique works by directing a controlled stream of inert nitrogen gas across the surface of a liquid sample, disrupting the solvent vapor boundary layer and accelerating evaporation. Because nitrogen is inert, it protects oxidation-sensitive analytes — a critical advantage when working with labile pharmaceutical compounds. Gentle heating of the sample bath further accelerates the process without subjecting samples to the thermal stress that could degrade unstable molecules.
Nitrogen blowdown serves as a critical bridge between sample extraction and instrumental analysis. In pharmaceutical bioanalytical labs, it is routinely used following SPE workflows to remove elution solvents, concentrate analytes, and enable solvent exchange before injection into LC-MS or GC-MS systems. Major SPE platform providers, including Waters Oasis, Agilent Bond Elut, and Phenomenex Strata, consistently specify evaporation under controlled conditions in their method development guides — and nitrogen blowdown is the preferred technique cited to prevent analyte loss and ensure reproducible sensitivity.
In drug discovery and combinatorial chemistry settings, nitrogen evaporation is used to remove solvents from compound libraries at scale. Microplate nitrogen evaporatorsare especially well-suited here, handling 96-well plate formats with the throughput and temperature uniformity required for high-volume screening operations.
Nitrogen blowdown is also a key step in preparing samples for GC-MS analysis. EPA Method 8270 specifically requires concentration of extracts under gentle nitrogen flow, and in metabolomics workflows, nitrogen drying between derivatization steps has been shown to increase signal intensity 2–10 fold by concentrating the derivatization reaction.
The primary challenges cited by nitrogen blowdown users in the 2026 survey were long evaporation times (69%), the need for constant monitoring (62%), and high gas consumption (46%). Automated nitrogen evaporators with programmable methods and bath temperature controls address the first two; nitrogen generators can substantially reduce the cost burden of the third.
The rotary evaporator — commonly known in labs as the "rotovap" — is a fixture in pharmaceutical chemistry labs involved in synthesis, natural product extraction, and API purification. It operates by rotating a flask partially submerged in a heated water bath while applying a vacuum, which lowers the boiling point of the solvent and spreads the liquid into a thin film that evaporates rapidly. The condensed solvent is collected separately for reuse or disposal.
In pharmaceutical research and development, rotary evaporators serve several key functions. They are widely used to concentrate and purify active pharmaceutical ingredients (APIs) from complex reaction mixtures, to remove residual solvents after synthesis steps, and to support recrystallization of pharmaceutical intermediates. Rotary evaporation has also been applied directly to polymorph and co-crystal screening— researchers have demonstrated the selective preparation of known polymorphic forms of aspirin and the discovery of a previously unknown polymorph of niflumic acid via rapid rotary solvent removal, as well as the scalable production of pharmaceutical co-crystals such as paracetamol:oxalic acid. For drug discovery researchers working through natural product libraries or synthesizing candidate molecules, the rotovap is often the primary tool for solvent management at the flask scale.
Solvent recovery is another important application. Pharmaceutical labs consume large quantities of expensive and regulated solvents, and rotary evaporators allow labs to recapture and reuse them — reducing both operational costs and environmental impact, in alignment with green chemistry principles.
The survey found that rotary evaporator users most frequentlyreport limited capacity (86%) as their top frustration, reflecting the method's batch-by-batch, single-flask operation. Long evaporation times (71%) and the need for constant monitoring (50%) also rank highly. These limitations make rotary evaporation less suitable for high-throughput sample preparation, but it remains the instrument of choice for synthetic chemistry and upstream purification work where its scale and solvent recovery capabilities are most valued.
Notably, only 21% of rotary evaporator users in the Organomation survey plan to change their workflows in the next year — suggesting that where the rotovap is used, it has earned an entrenched and well-justified role.
Centrifugal vacuum concentrators — most widely recognized under the tradename SpeedVac® — are the instrument of choice when pharmaceutical labs need to process large numbers of small-volume biological samples simultaneously, without the risk of sample loss from bumping or splashing. These systems combine centrifugal force, heat, and vacuum to evaporate solvents from samples arranged in a rotating rotor. The centrifugal force keeps liquids pressed against the tube wall, preventing the violent boiling that could otherwise eject sample material.
In pharmaceutical bioanalysis, centrifugal concentrators are extensively used for metabolomics profiling of plasma, drug metabolism studies, and identification of drug metabolites and biomarkers in biological fluids such as urine and blood. Peer-reviewed metabolomics protocols in cancer biomarker research, for example, routinely call for SpeedVacconcentration of protein-precipitated plasma extracts ahead of LC-MS analysis — often without applied heat, to protect labile metabolites. Proteomics labs similarly rely on these systems for concentrating peptide digests and biological extracts ahead of mass spectrometry, and drug discovery teams use them for combinatorial chemistry applications involving aggressive organic solvents.
The method's suitability for sensitive biological samples makes it especially valuable in translational pharmaceutical research, where the sample matrix is complex and analyte quantities are often limited. The ability to process dozens — or in some configurations, more than 100 — samples simultaneously in a single instrument gives centrifugal evaporation a throughput advantage that neither rotary evaporation nor freeze drying can match at the bench-scale sample prep level.
The 2026 survey shows that centrifugal/vacuum evaporation is tied with nitrogen blowdown as the second most common method for pharmaceutical sample type workflows at 56% each. Among centrifugal users who plan to change their workflows, a striking 86% cite the adoption of new methods or applications as the primary driver — suggesting this is an actively growing and evolving segment of pharmaceutical laboratory practice.
The most commonly reported frustrations among centrifugal users are long evaporation times (52%), limited capacity (46%), and the need for constant monitoring (44%).
The Organomation 2026 survey makes clear that pharmaceutical laboratories are not relying on a single evaporation method. Over 58% of all surveyed labs use multiple evaporation methods for separate applications — and in pharmaceutical settings, this multi-method reality is particularly pronounced.
A common pattern in pharmaceutical labs looks something like this: rotary evaporation for synthetic chemistry and API purification upstream; nitrogen blowdown for SPE-based bioanalytical prep; centrifugal vacuum concentration for high-throughput biological sample processing; and freeze drying for final formulations of labile biologics and for stabilizing analytical reference samples.
Across all four methods, the survey data surfaces a consistent theme: long evaporation times are the dominant shared frustration (59% of all respondents). This signals an industry-wide pressure to improve throughput without compromising sample quality — a challenge that instrument selection, automation, and optimized method parameters can all help address.
As pharmaceutical labs increasingly prioritize speed, scalability, and reduced manual intervention, the evaporation equipment choices they make today will directly shape the productivity and data quality of their workflows tomorrow. Understanding the strengths and limitations of each method is the essential first step.