residual moisture comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-05-15. Where a claim depends on a specific study, the study is described rather than over-claimed.
Lyophilization removes water from a frozen material by sublimation under reduced pressure. The process begins with freezing, which converts liquid water into ice and fixes the structure of the sample. After freezing, primary drying lowers pressure so ice changes directly to vapor without passing through a liquid phase. Secondary drying then removes bound water that remains after ice sublimation. The result is a dry, porous solid that often retains its original shape.
The low pressure used during drying allows water vapor to move from the ice surface to a cold condenser. Energy supplied as heat drives sublimation but must stay below the collapse temperature of the frozen matrix. If the product becomes too warm, the frozen structure may soften or melt, reducing pore formation and slowing drying. Formulations often include bulking agents, stabilizers, or buffers to support a rigid cake. The final moisture content depends on formulation, freezing rate, and the length of secondary drying.
Freeze-drying is distinct from simple evaporation and from spray drying. Evaporation removes water at temperatures above freezing, while spray drying rapidly dries droplets in a heated gas stream. Lyophilization avoids high temperatures, which can be useful for heat-sensitive materials such as proteins, vaccines, and some foods. The porous cake produced by sublimation dissolves or rehydrates more quickly than a dense dried mass. Not all materials tolerate freezing or the pH shifts that can occur as solutes concentrate during ice formation.
Residual moisture is a key quality attribute for lyophilized products. Water that remains after secondary drying can affect chemical stability, cake structure, and shelf life. Karl Fischer titration is a common method for measuring water content in the dried solid. The target range varies by product, but many biologics are dried to between 0.5% and 3% water by weight. Acceptable limits are set during development and confirmed by stability studies.
Stability studies examine how temperature, humidity, and time influence a lyophilized product. Accelerated conditions provide early information about degradation pathways, while long-term studies support shelf-life claims. The glass transition temperature of the dried formulation can indicate its physical stability, and storage above this temperature may increase molecular mobility and lead to collapse or aggregation. Container closure integrity also matters because moisture or oxygen ingress can degrade the product, so vial stoppers and seals are part of the quality system.
| Property | Value | Notes |
|---|---|---|
| Primary phase change | Sublimation | Ice changes directly to vapor under reduced pressure |
| Typical chamber pressure | 0.01–0.5 mbar (1–50 Pa) | Below the triple point of water; product-specific |
| Typical product temperature during primary drying | −40 °C to −10 °C | Kept below collapse temperature |
| Typical residual moisture | 0.5–3% w/w | Target range varies by formulation and use |
| Common synonyms | Freeze-drying; lyophilisation | Lyophilization is the US spelling |
In the ensuing power struggle for control over the province, General Wang Zuanxu made a deal with Liu that he would return the Ya'an and Xichang regions to Xikang as well as subsidize the Xikang government with 360,000 yuan per year in exchange for Liu's support. This deal went through, and the central government even agreed to fund a highway from Sichuan to Xikang. On 28 November, 1938, the Executive Yuan ratified the establishment of Xikang Province, which was officially inaugurated on 1 January, 1939. Liu Wenhui became the governor of Xikang. In exchange, Wang Zuanxu was able to become the acting chairman of Sichuan Province, although he failed to secure control and was later usurped by Chiang Kai-shek himself. Liu Wenhui's provincial government was highly nepotistic, made up mostly of personal connections, secretaries, and subordinate officers. Only one politician in the new government, Ye Xiufeng, was a Chiang loyalist: he was subsequently outmaneuvered by Liu and dismissed within two years. Although the Tibetan population were hopeful that the establishment of the province would entail increased representation, Liu only appointed one Tibetan, a monk, to the governing board. This was justified by the national government as a prioritization of national stability over minority rights, ensuring that the Xikang government remained Han-centric and Han-dominant. In addition, the wartime situation meant that by cooperating with the central government, Liu Wenhui would be able to maintain his rule over Xikang.
Clinical trials involving new drugs are commonly classified into five phases. Each phase of the drug approval process is treated as a separate clinical trial. The drug development process will normally proceed through phases I–IV over many years, frequently involving a decade or longer. If the drug successfully passes through phases I, II, and III, it will usually be approved by the national regulatory authority for use in the general population. Phase IV trials are performed after the newly approved drug, diagnostic or device is marketed, providing assessment about risks, benefits, or best uses.
Navacaprant (developmental code names include BTRX-335140, BTRX-140, CYM-53093, NMRA-335140, and NMRA-140) is a selective κ-opioid receptor (KOR) antagonist which is under development for the treatment of major depressive disorder and bipolar depression. It was originated by BlackThorn Therapeutics and is being developed by Neumora Therapeutics. As of February 2025, navacaprant is in phase 3 clinical trials for major depressive disorder. In January 2025, it was disclosed that navacaprant had failed to show effectiveness for major depressive disorder in a phase 3 trial. Upon this announcement, the stock price of Neumora Therapeutics decreased by 80%.
Sources: en.wikipedia.org
Karin Markides, born 1951, is a Swedish professor in analytical chemistry and president and CEO of Okinawa Institute of Science and Technology from 1 June 2023. She was the president of American University of Armenia from 1 July 2019 to 2 December 2022. She was also the president and CEO of Chalmers University of Technology from 2006 to 2015. From 2004 to 2006 she was vice director general for Vinnova. She is also board member of the Royal Swedish Academy of Engineering Sciences since 1992 and a board member of the Royal Swedish Academy of Sciences since 1999. Markides completed her doctorate degree at Stockholm University 1984 with the thesis Organosiloxanes containing cyano groups for capillary chromatography. Following this she started her research career at Brigham Young University in Utah, USA, first as a postdoc, and later as research assistant and associate director. In May 1990 she returned to Sweden as a professor at Uppsala University. Fourteen years later, in May 2004, she was employed as vice director general of Vinnova, the Swedish innovation agency. Markides has been chairman of the Scientific Council for Sustainable Development under the Swedish government (vetenskapliga rådet för hållbar utveckling) since 2015. The council's mission is to give evidence-based, concrete suggestions for development of financial, ecological, cultural and social sustainability for the government's longterm sustainability vision.
In the United Kingdom, a television advertisement campaign, the Gold Blend couple starring Anthony Head and Sharon Maughan ran in 12 instalments between 1987 and 1993. The first 11 episodes were released as a promotional compilation video called Love Over Gold in 1993. A novelisation of the same name written by Susan Moody (under the pseudonym Susannah James) was released in the same year. The legendary boxer Chris Eubank and soccer star Ian Wright featured separately in television ads in the late 1990s and 2000s. Before the Gold Blend couple made their debut, a series of British adverts for Nescafé starred Gareth Hunt, shown shaking his closed hand and opening it to reveal coffee beans, then smelling the aroma. Greene, who starred in some 26 adverts, commented that the shaking of the beans was crucial to the campaign's success, due to their sexual connotations. By 1986, adverts in this campaign also starred Sarah Greene and Mike Smith. In the 1986 Smash Hits readers poll, Nescafé were simultaneously ranked fifth in the "Best TV Ad" category and first in the "Worst TV Ad" category. In 2003, the company reintroduced the Nescafé brand in Canada and the US, and the product is now known as Nescafé Taster's Choice. It is sold in North American supermarkets in both glass and plastic packaging. While the Nescafé brand was created for soluble coffee, it has subsequently been used as an umbrella brand on a number of instant coffee products, including, in the UK, Gold Blend and Blend 37 freeze-dried coffees.
Large very-low-density lipoprotein particles (VLDL-P) Small low-density lipoprotein particles (LDL-P) Large high-density lipoprotein particles (HDL-P) VLDL size LDL size HDL size These markers assess lipid metabolism linked to insulin resistance, in which cells respond poorly to insulin, often preceding type 2 diabetes and cardiovascular disease. Multiple studies, reported that it predicts future type 2 diabetes risk effectively, even outperforming traditional markers like fasting glucose in some cases. The LP-IR score offers early detection of insulin resistance, even in people with normal blood glucose, making it useful for preventive health strategies. It is simple, affordable, and doesn't require insulin or glucose measurements, avoiding issues with insulin assay variability.
Sources: en.wikipedia.org
In addition to providing flexibility and length, the poly dA portion of the linker also allows further purification of the mRNA-peptide fusion due to its high affinity for dT cellulose resin. The mRNA-peptide fusions can be selected over immobilized selection targets for several rounds with increasing stringency. After each round of selection, those library members that stay bound to the immobilized target are PCR amplified, and non-binders are washed off.
Tetrapeptide-21 (GEKG peptide) is a tetrapeptide that is derived from a sequence found in connective tissue proteins such as collagens and elastin. It stimulates endogenous biosynthesis of collagens, fibronectin and hyaluronic acid, and is used in skincare products for its purported anti-aging effects.
Fabomotizole (INN), sold under the brand name Afobazole, is an anxiolytic drug launched in Russia in the early 2000s. It produces anxiolytic and neuroprotective effects without any sedative or muscle relaxant actions. Its mechanism of action remains poorly defined however, with GABAergic, NGF- and BDNF-release-promoting, MT1 receptor agonism, MT3 receptor antagonism, and sigma agonism suggested as potential mechanisms. Fabomotizole was shown to inhibit MAO-A reversibly and may potentially have some involvement with serotonin receptors. Clinical trials have shown fabomotizole to be well tolerated and reasonably effective for the treatment of anxiety. Experiments in mice have shown antimutagenic and antiteratogenic properties. Experiments in rats have shown beneficial effect in the model of ischemic stroke. Fabomotizole has found little clinical use outside Russia and has not been evaluated by the FDA.
During the recording of A Loner, Chanut used an old Marshall JMP head to add more upper mids, giving the sound a more defined character. To get a "really fat sound" in the studio, he used his Rivera electric guitar amplifier, the brand's first generation. For the electric guitar parts, the band wanted a "bright sound" with less gain and "to remove this flattering aspect" of the sub-bass characteristic of doom or sludge metal. To "let the music breathe more" and to highlight the guitar effects, particularly the reverbs, Thépegnier decided to "lighten" his drumming. Thépegnier further stated that they wanted to "lighten" their sound and achieve this "bright" result that would enable them to embrace "our cold ambiences even more. Getting out of our 'doomy' comfort zone". Journalist Jean-Charles Desgroux wrote that the band "dares to experiment" on A Loner and "beyond doom, sludge or at worst that muddy stoner which they will never claim". David wrote in his review of A Loner: "The French group experiments, plays with effects, textures and nuances". At this stage of their musical evolution, they demonstrated a greater presence of melodies and introspection and were sometimes more atmospheric. While Hangman's Chair blended various doom sounds to create an atmosphere on This Is Not Supposed To Be Positive, they sounded, on A Loner, like a different band from their earlier work, with gothic sounds closer to goth rock and cold wave than metal at this stage. The "stoner band" they had been in the past had nevertheless left some "artefacts" in their music.
Sources: en.wikipedia.org
Lyophilization relies on sublimation, so water moves from solid ice to vapor without becoming liquid. The material is frozen, pressure is reduced, and controlled heat is supplied. Vapor is captured on a cold condenser, leaving a dry porous solid.
The process has three main stages: freezing, primary drying, and secondary drying. Freezing sets the ice structure, primary drying removes free ice, and secondary drying removes bound water. Each stage uses specific temperature, pressure, and time settings.
No, it is a drying method rather than a sterilization method. Removing water can limit microbial growth, but it does not reliably kill microorganisms. Sterility must come from separate steps such as filtration, heat treatment, or aseptic processing.
Residual moisture can influence chemical degradation, cake collapse, and long-term stability. Low moisture levels usually improve stability, but each product has an optimal range.