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 2025-08-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
Stability of a lyophilized solid depends on water content, temperature, and the physical state of the formulation. Amorphous products may slowly absorb moisture and drop below their glass transition temperature, causing collapse or crystallization. Some proteins and peptides can aggregate even in a dry state, especially when exposed to heat or moisture. Accelerated stability studies at elevated temperature and humidity help estimate shelf life, but real-time data remain the basis for expiration dating.
After drying, a lyophilized product is usually sealed under vacuum or an inert gas to limit moisture and oxygen exposure. The container closure system matters because stoppers and seals can allow moisture ingress over time. Storage conditions are selected from stability studies that track potency, cake appearance, and reconstitution behavior. Many freeze-dried materials are kept at controlled room temperature, while some require refrigeration or protection from light.
Quality control for freeze-dried forms includes visual inspection, water content measurement, and reconstitution time. A satisfactory cake is typically uniform, porous, and intact, although minor shrinkage or cracking may be acceptable if specifications allow. Karl Fischer titration, thermal gravimetric analysis, and near-infrared spectroscopy are used to measure water content. Reconstitution is assessed by adding a specified diluent and recording the time and ease of dissolution. Microbiological and particulate tests are added when the product is sterile or intended for injection.
Handling practices aim to prevent moisture ingress and mechanical damage. Vials should remain stoppered and crimped until use, and reconstitution should follow the labeled diluent and volume. Shipping may involve temperature-controlled containers and desiccants, but direct contact between desiccant and product is avoided. Regulatory guidance expects documented storage conditions, excursion assessments, and stability commitments. Open questions remain about how best to predict long-term stability from short accelerated studies for every formulation class.
After lyophilization, the product is usually a porous cake or powder with a large internal surface area. This structure can absorb moisture quickly if exposed to humid air, so vials are sealed under vacuum or an inert gas. Moisture uptake may lower the glass transition temperature of the dried matrix and accelerate chemical or physical degradation. Storage conditions therefore depend on the formulation, container, and intended shelf life. Some products remain stable at room temperature, while others require refrigeration or freezing.
| Property | Value | Notes |
|---|---|---|
| Appearance | Porous cake or plug | Uniform structure suggests the drying cycle preserved the matrix. |
| Reconstitution time | Usually under 2 minutes | Depends on cake porosity, diluent volume, and excipient composition. |
| Water content range | 0.5–3% w/w | Common specification range; exact limits are product-specific. |
| Headspace oxygen | <1% v/v | Inert gas backfill reduces oxidation of sensitive materials. |
| Storage temperature | 2–8 °C or controlled room temperature | Choice depends on accelerated and real-time stability results. |
Stability programs monitor lyophilized products under defined temperature and humidity conditions over time. Real-time studies at recommended storage conditions are the reference, while accelerated studies provide early signals of degradation pathways. Because a dry cake can still undergo oxidation, hydrolysis, or aggregation, stability depends on residual moisture, excipients, and container headspace. Open questions include how best to predict long-term stability from short accelerated runs and how vial-to-vial variability affects shelf life. Current guidance treats these predictions as product-specific rather than universally generalizable.
Freeze-dried materials are hygroscopic to varying degrees and can take up moisture after drying. Storage therefore often uses sealed glass vials, rubber stoppers, and crimp seals to limit contact with ambient humidity. A desiccant may be included for moisture-sensitive products, although it is not universal. Controlled room temperature is sufficient for many lyophilizates, while others require refrigeration or freezing. Moisture ingress remains a primary cause of cake collapse, chemical degradation, and loss of reconstitution performance.
Quality assessment of a lyophilized product includes cake appearance, residual moisture, reconstitution time, and container closure integrity. A uniform, porous cake suggests that freezing and drying stayed within the formulation's design space. Cracks, shrinkage, meltback, or a glassy film can indicate thermal abuse or a formulation problem. Analysts also test for subvisible particles and sterility when the product requires those specifications. Visual inspection alone cannot confirm biological activity or chemical stability, so it is combined with analytical methods.
Quality control for lyophilized materials includes visual inspection, residual moisture measurement, and reconstitution testing. Cake appearance can reveal process problems such as collapse, shrinkage, or meltback, although appearance alone does not prove potency. Residual moisture is commonly measured by Karl Fischer titration or by loss on drying. Reconstitution time is checked because a slow or incomplete dissolve can indicate a change in pore structure. Stability studies track these attributes over time under defined temperature and humidity conditions.
Analytical methods for lyophilized solids must account for the low moisture content and the fragile cake. Karl Fischer titration is widely used for water content, while near-infrared spectroscopy can measure moisture non-destructively in sealed containers. X-ray diffraction and modulated differential scanning calorimetry help identify crystalline or amorphous phases. Residual solvent analysis may be needed if organic solvents were used during formulation. The combination of these methods supports batch release and long-term stability assessment.
Lyophilized products are typically stored as sealed solids in vials or syringes. Moisture ingress is a major concern because many dried cakes are hygroscopic and can lose stability when exposed to humid air. Storage temperature depends on the formulation; some products are kept refrigerated, while others are stable at room temperature. Container closure integrity and headspace moisture are often monitored. Light protection may also be required for some photosensitive materials.
== Classification == This mushroom has been placed in the section Aztecorum by Gaston Guzman; other members of the section include Psilocybe aztecorum var. aztecorum, Psilocybe aztecorum var. bonetii, Psilocybe pseudoaztecorum, and Psilocybe quebecensis.
=== 2000 === 13 March The Secret Life of the Crash Test Dummy, about the biomechanics of car crashes; a typical crash test dummy cost around £100,000, with about three hundred individual parts, that had to be included by safety law, and new cars could not be sold until the dummy had tested it sufficiently; the Volvo 300 1980s television advert; Lt-Col Wayne Mattson of the USAF and a strange crash in New Mexico, one hundred miles north of the Trinity (nuclear test), and near White Sands Missile Range, where German V-2 missiles were being tested, which were conveniently blamed by the USAF on anthropomorphic dummies; John Melvin (engineer) and the legacy of USAF biophysicist and doctor Colonel John Stapp, who mostly invented aviation safety testing; John Stapp conducted gruesome horrific deceleration tests on himself; Alderson had made artificial limbs for injured USAF World War II pilots, so made a full artificial proto-human; John Stapp tested his dummies in vehicles; Clarence Ditlow and the Center for Auto Safety; in 1966 it became legal in the US for new cars to have been tested by dummies; mathematical models of injury were needed, to translate the acquired crash data into possible effects on the human body, worked out by mechanical engineer Walter Pilkey of the University of Virginia; Scottish orthopaedic surgeon Angus Wallace and impact speed on bone tensile strength; in 1976 the Hybrid III dummy was designed, the automotive industry standard design; David Abbott, advertising executive; the data for designing the crash test dummy, Hybrid III, was mostly derived from data procured for human male occupants - and typical (fiftieth percentile) males, not female, and females had much different bodies; child dummies were essentially smaller adult male dummies, which was not biologically true; new dummies were developed at the National Transportation Biomechanics Research Center. Narrated by Andrew Lincoln, produced by Cathy Rogers, directed by Peter Webber, made by RDF Television. Shown on Wednesday 17 January 2001 on The Nature of Things in Canada 20 March Rise and Fall of GM Food, about genetically modified food; Belgian geneticist Marc Van Montagu, of the University of Ghent, visits Havana in Cuba, where a new research centre opened with Carlos Borroto; protests by topless women; GM was largely first developed by Mexican geneticist Herrera Estrella, of the Centre of Investigation and Advanced Studies; Rob Fraley of Monsanto; US farmers spend $8bn dollars on herbicides and pesticides; Roger N. Beachy had a breakthrough in 1986 at the Washington University in St. Louis, now at the Donald Danforth Plant and Science Center; Monsanto made the first insecticide-resistant plant in 1987; many African farmers cannot afford insecticides; Cyrus Ndiritu of the Kenya Agriculture Research Institute; much food harvested in Africa does not last before it reaches the consumer; in 1990 Don Grierson of the Plant Science Division of the University of Nottingham found genes of ripening; Channapatna Prakash of Tuskegee University in Alabama; aluminium toxicity of soils in tropical countries affected yield; Julian Borger of The Guardian; biologist Mae-Wan Ho of the Open University; biologist John Gatehouse of the University of Durham, and the Pusztai affair at The Rowett Institute; Helen Browning, Chairman of the Soil Association; former Vice-Chancellor of UEA, Derek Burke; former Independent environment correspondent Richard D. North, who had grown out of love with the hard-line environmental movement; European farmers grew five times more produce than they did in the 1960s, and there were twice as many trees in the UK than in the 1920s; Renée Elliott of Planet Organic; around 100m children in Third World countries suffered from Vitamin A deficiency. Directed by Martin Durkin, made by his company Kugelblitz 27 March Simply Complex, about the physicist Murray Gell-Mann; by an accident, he devised strangeness of sub-atomic particles, in his mid-20s; he predicts an omega minus particle, which was found in 1962; he predicts that the proton and neutron were made of three triplet particles, which he called quarks from Finnegans Wake and his Eightfold way (physics), also predicted by George Zweig; he worked closely with Richard Feynman at Caltech in the 1960s; on 30 October 1969 he is told that he had won the Nobel Prize for Physics; his friendship with MIT mechanical engineer Seth Lloyd; British physicist Geoffrey West; the documentary is in a biographic informal style that Horizon has since often followed. Produced by Barbara Altounyan, directed by Celia Lowenstein, made by Diverse Productions 3 April Meningitis - Search for a Cure, 3,000 people in the UK had meningitis in 1999; microbiologist Martin C. J. Maiden; one in five died from meningococcal disease; damage is caused by the endotoxin (lipopolysaccharide); a healthy survey is carried out at Burford School; Mike Levin (paediatrician) at Imperial College, and how meningitis A is a huge danger in Africa; 60% of cases in the UK are meningitis B, and many such cases are treated at St Mary's Hospital, London; Brett Giroir of the Children's Medical Center Dallas; 17-year-old Amy Mansell from Whitstable was in a coma for five weeks. Narrated by Paul Brightwell, produced by David Dugan, directed by Jeremy Llewellyn-Jones, made by Windfall Films with Nova and WGBH Boston. It was shown on Nova as Killer Disease on Campus, episode 9 of season 29, shown on 3 September 2002, and shown under the original programme title as a half-hour programme on 6 November 2003 on Catalyst on ABC in Australia 10 April The Box, about flight recorders, with ValuJet Airlines Flight 592 which crashed on 11 May 1996; voice recorders have been compulsory since the late 1960s; Dukane Seacom make emergency underwater locator beacons (ULBs); the Boeing 737, which had around 21,000 take-offs per day, was believed to have unreliable rudder control since the 1980s, as shown in the United Airlines Flight 585 crash on 3 March 1991, having had two rudder incidents in the previous two weeks, with the aircraft flipping 35 seconds after take-off and crashing all in seven seconds; the electrohydraulic servo valve in the Boeing 737 rudder control unit was thought to be sometimes temperamental; Boeing claimed that the March 1991 crash was due to a rotor or lee wave, caused by nearby mountains; the USAir Flight 427 crash on 8 September 1994, where the aircraft flipped at 6,000 ft, in 28 seconds crashing; British Airways did not rely on their Penny & Giles quick access recorders, and would consolidate this data where anomalies were checked, so the NTSB needed BA's data for their 737 aircraft; this safer BA method was introduced by the previous British European Airways (BEA) when it had to prove to the CAA that its autoland system for the Trident was safe, in the Civil Aircraft Airworthiness Data Recording Programme which since 1990 has been collected by the British Airways Safety Information System (BASIS); the 1991 crash investigation concluded after 8 years in 1999, with Boeing ordered to redesign the servo valve. 9 October Full Throttle, about the technology and psychology of motor racing; Brazilian driver Christian Fittipaldi; the Eurofighter, controlled by computers, and due to enter RAF service in 2002; Archie Neill, BAE test pilot; Stephen Olvey, motor racing medical officer; driver Mark Blundell; the Long Beach Grand Prix in Los Angeles; Steve Clark, engineer for Mercedes; Brian Lisles and Peter Gibbons of Newman Haas Racing; the edge of performance envelope; Mario Andretti, former driver: Edward Winter of Sheffield Hallam University and predicting outcomes in sport, by intuition; John Rothwell of the Institute of Neurology in London, testing reflexes, by an MRI scanner, and how the brain stores instructions; psychologist Mike Land of the University of Sussex, and the psychology of prediction, and feedforward; life expectancy of racing drivers in the 1970s was short; racing drivers had risk positive personalities, and became accustomed to risk; psychologist Tim Wheeler; Jimmy Vasser of Chip Ganassi Racing; a female violinist plays La fille aux cheveux de lin; sports psychologist Brian Hemmings; Austrian driver Alexander Wurz of Benetton Formula; RAF SEPECAT Jaguar XZ103 of 41 Squadron; engineer Pat Symonds of Benetton Racing; Simon Taylor (journalist) of Motor Sport; Graham Rood of DERA Air Systems in north Hampshire. Narrated by Stephen Rashbrook, produced by Patrick Uden, directed by Andy Robbins, made by Uden Associates 16 October Lethal Seas: the Maelstrom, about ocean whirlpools; the Gulf of Corryvreckan in Scotland, Lofoten and Saltstraumen in Norway; with Prof Tsukasa Nishimura of Tokyo University of Science and Prof Walter Munk of the Scripps Institution of Oceanography; the Firth of Lorn in west Scotland has one of the world's most dangerous whirlpools, the Royal Navy avoids it; atmospheric physicist Peter Read; mathematician David Dritschel, and the Great Red Spot vortice; the dangerous Arran Rapids on the Cordero Channel in western Canada; Burkard Baschek of the Institute of Ocean Sciences, who dropped a CTD (instrument) into the torrential river currents; Tremble Island in the notorious Slingsby Channel, where a geophone was placed; the novel A Descent into the Maelström; Bjørn Gjevik, a fluid dynamicist in the Department of Mathematics, at the University of Oslo; strong tidal currents in the Naruto Strait in Japan, and the Naruto whirlpools. Narrated by Stephen Rashbrook, produced by Robert Sproul-Cran, directed by Kim Flitcroft, made by Northlight Productions with the Discovery Channel 23 October Einstein's Biggest Blunder, about calculations of the expansion of the universe; the documentary opens with a pastiche of the Star Wars opening credits; two physicists met in 1996, with a new radical proposal for explaining the many anomalies in the expansion of the universe - Andreas Albrecht (cosmologist) of the University of California, Davis and João Magueijo of Portugal; Dave Wark of the University of Sussex, visits Bern in Switzerland; Ruth Durrer of the University of Geneva; John E. Baldwin of the University of Cambridge, and the 1887 Michelson–Morley experiment, which found that the Earth's rotational speed did not affect the speed of light in any way, alongside the Venus movement of The Planets; to account for this, Einstein made his field equations, and lambda - the cosmological constant was added by Einstein to account for how space-time would need to expand; Einstein's equations inferred that the expansion of the universe rested on inherently unstable conditions; due to the Doppler effect, background radiation from the Big Bang is now perceived as microwave radiation; Richard Ellis (astronomer) of Caltech; Einstein didn't believe in the Big Bang until a meeting with Hubble in 1932 in California; with the new theory of an expanding universe, the cosmological constant was now required, but the precise trajectory of the expansion of the universe could not be directly predicted, which led to the flatness problem; the theory of inflation was put forward by Alan Guth in the 1970s; when at St John's College, Cambridge, João Magueijo had the radical proposal that if the speed of light was higher, in the early universe, a cosmological horizon of sufficient distance would be possible, to explain the predicted conditions of the expansion of the early universe, and the cosmological constant problem; the Royal Society gave him a research fellowship to work at Imperial College; as further exploratory work was clocked up, with calculations inclya variable speed of light, the team of physicists looked at other applications for their controversial proposals, such as the flatness problem, and what happened before the Big Bang; in 1998 astrophysicist John Webb, at the University of Cambridge, worked on the theory of a variable speed of light, through investigating quasars, the most distant objects that can be seen; and by looking at supernovae, it was largely expected that any recorded data would show indications of a deceleration in the rate of expansion of the universe, but the data instead showed that the rate of expansion was - increasing, which led to the lambda-CDM model. Narrated by Scottish actor Matthew Zajac, directed by David Sington, made by Dox Productions 30 October The Science of Stress, with 42-year-old actor Angus Kennedy; endocrinologist Stafford Lightman of the University of Bristol; Vivette Glover, a perinatal psychobiological at Imperial College; Sir Cary Cooper, psychologist at the former UMIST; Carolyn M. Mazure, psychiatrist at Yale School of Medicine; Charles Nemeroff, psychiatrist at Emory University School of Medicine. Narrated by Geoffrey Palmer, directed by Michael Samuels, produced by Bridget Sneyd, made by Lion Television and the Discovery Health Channel 7 December Science of Crime - Psychopath, with psychologists Robert D. Hare and Adrian Raine, about the psychopathic traits of insincere superficial charm, on the Psychopathy Checklist. Narrated by Neil Pearson, directed by John Purdie, produced by Rosalind Arden, made by Union Pictures 14 December Science of Crime - Criminal Evidence, about the forensic psychologist 49-year-old Kathy Reichs. Produced by Geoff Deehan, directed by Roger Pyke, made by Yap Films 21 December Science of Crime - Cybercops, the Hackers on Planet Earth conference; Cult of the Dead Cow, founded by Swamp Rat, and its Back Orifice software for accessing Windows 98; the Happy99 virus; wardialing; part of the High Technology Theft Apprehension and Prosecution Program in California. Narrated by Steven Mackintosh, written by Callum Macrae, directed by Witold Starecki
One example, in which both plant and animal alkanes play a role, is the ecological relationship between the sand bee (Andrena nigroaenea) and the early spider orchid (Ophrys sphegodes); the latter is dependent for pollination on the former. Sand bees use pheromones in order to identify a mate; in the case of A. nigroaenea, the females emit a mixture of tricosane (C23H48), pentacosane (C25H52) and heptacosane (C27H56) in the ratio 3:3:1, and males are attracted by specifically this odor. The orchid takes advantage of this mating arrangement to get the male bee to collect and disseminate its pollen; parts of its flower not only resemble the appearance of sand bees but also produce large quantities of the three alkanes in the same ratio as female sand bees. As a result, numerous males are lured to the blooms and attempt to copulate with their imaginary partner: although this endeavor is not crowned with success for the bee, it allows the orchid to transfer its pollen, which will be dispersed after the departure of the frustrated male to other blooms.
== History == Doxylamine is a first-generation antihistamine and was discovered by Nathan Sperber and colleagues and was first reported in 1948 or 1949. It has been the antihistamine component of NyQuil since 1966. Bendectin, a combination of doxylamine, pyridoxine (vitamin B6), and dicyclomine (an anticholinergic antispasmodic agent), was marketed for treatment of morning sickness in 1956. This product was reformulated in 1976 to remove dicyclomine. The reformulated product was voluntarily discontinued by the manufacturer in the United States in 1983 due to concerns about an alleged association with congenital limb defects. However, these concerns have not been supported by studies. In 2013, doxylamine/pyridoxine was reintroduced in the United States under the brand name Diclegis. The combination was not removed from the market in Canada, where it had been marketed since 1979.
=== Unmelted sample analysis === Methods to analyze the microbe populations of colder, unmelted ice samples (cold enough to prevent brine drainage) under microscopes were developed by designing specialized equipment. Epifluorescence microscopes that can operate at subzero temperatures allowed researchers to observe undisturbed brine pool microbe populations with the addition of DAPI (DNA staining 4', 6-diamidino-2-phenylindole) mixed into an adequately salty and cold brine solution to highlight non-autofluorescing microbes. Alternatively, a microscope with a cold stage, commonly used to study glacial ice, may also be used to study unmelted sea ice with the right modifications. Other stains such as Alcian Blue (stains extracellular polysaccharide substances) and CTC (stains oxygen-respiring bacteria, 5-cyano-2,3-ditolyl tetrazolium) have also been used. Alcian Blue stains have revealed that extracellular polymeric substances (EPS) are ubiquitous throughout brine pools found in sea ice, even without any microbes visible in the brine pool. Some EPS originates from seawater before freezing but is also produced in copious amounts within algal bands and by bacteria to a lesser extent but throughout the entirety of the sea ice. CTC stains have indicated greater percentages of microbial activity within the sea ice when compared to the seawater below it, especially bacteria associated with particulate matter.
Sources: en.wikipedia.org
=== Ireland === In 2019, the chain announced plans to open a restaurant in Dublin, Ireland, with 40 total sites in Ireland planned from 2020. As of early 2026, there are two locations in Ireland, both of them in Dublin.
== Overdose == Overdose in animals produced effects including convulsions, tremor, paralysis, inactivity, extremity erythema, abnormal breathing, cyanosis, ataxia, mydriasis, and injection site reactions. The elimination half-life of sumatriptan in humans is 2.5 hours. The effect of dialysis on sumatriptan levels is unknown. Overdose of sumatriptan can cause sulfhemoglobinemia, a rare condition in which the blood changes from red to green, due to the integration of sulfur into the hemoglobin molecule. If sumatriptan is discontinued, the condition reverses within a few weeks.
R-NH2 + DBNPA → R-NH-C(Br)(NO2)NH2 In basic environments, DBNPA undergoes nucleophilic substitution by hydroxide ions, which initiates hydrolysis. This reaction reduces the environmental persistence of DBNPA by breaking it down into smaller degradation products.
== Naming conventions == Amines are named in several ways. Typically, the compound is given the prefix "amino-" or the suffix "-amine". The prefix "N-" shows substitution on the nitrogen atom. An organic compound with multiple amino groups is called a diamine, triamine, tetraamine and so forth. Lower amines are named with the suffix -amine.
. There is general formula for friction force in a liquid: The vector differential of friction force is equal the viscosity tensor increased on vector product differential of the area vector of adjoining a liquid layers and rotor of velocity:
Sources: en.wikipedia.org
Sealed vials or containers should be kept at the temperature specified by stability data, often controlled room temperature or 2–8 °C. Moisture and oxygen barriers are important because both can degrade sensitive materials. Opened containers may need immediate use or protection from ambient humidity.
It usually appears as a uniform porous plug or cake that fills the container without excessive shrinkage. Color should match the specification, and there should be no meltback or visible foreign matter. Minor cracking may be acceptable if the product still meets moisture and potency limits.
Water content is a key stability parameter because excess water can promote hydrolysis, aggregation, or cake collapse. It also affects reconstitution and product weight. Each product has a target range, and methods such as Karl Fischer titration are used to verify it.
Collapse occurs when the product temperature rises above its collapse or eutectic temperature during drying. The frozen matrix loses structure, producing a shrunken or melted appearance. This can slow reconstitution and may affect stability.