residual moisture is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Stability of a lyophilized product depends on its glass transition temperature, the temperature at which the amorphous cake transitions from a glassy to a rubbery state. Storage below this temperature minimizes molecular mobility and slows chemical degradation. If the storage temperature exceeds the glass transition temperature, the cake may collapse, shrink, or become sticky. Accelerated stability studies at elevated temperatures and humidity help predict shelf life, but they do not always reflect real-time behavior. Residual moisture content also plays a critical role in long-term stability.
Reconstitution involves adding a suitable diluent, often sterile water or a buffer, to the dried cake. Gentle swirling or inversion helps dissolve the material without creating excessive foam. The time required for complete dissolution can range from seconds to several minutes and depends on the cake structure and the diluent. Improper reconstitution, such as vigorous shaking or using the wrong diluent, can cause protein aggregation or loss of activity. After reconstitution, the product may have a limited shelf life and should be used according to its labeling.
Lyophilization is a dehydration technique in which a product is frozen and the solvent is removed under reduced pressure. The low pressure allows ice to sublimate directly into vapor without passing through a bulk liquid phase. This differs from conventional drying, where heat drives evaporation and can damage heat-sensitive structures. The process is used for biological materials, pharmaceutical formulations, and some foods. Its main advantage is preservation of porous structure and rapid reconstitution.
Freezing is the first stage and sets the ice structure that later becomes the pore network. The formulation is cooled below its freezing point, often with a controlled ramp, and solutes concentrate as ice forms. Primary drying then lowers chamber pressure and supplies heat to sublime the ice. The product temperature must stay below its collapse or eutectic temperature to prevent structural loss. Secondary drying raises the temperature modestly to remove bound water and achieve a low residual moisture.
A freeze-dryer consists of a vacuum chamber, temperature-controlled shelves, a condenser, and a vacuum pump. Vials, ampoules, or bulk trays hold the product during the cycle. The condenser traps water vapor as ice at a temperature lower than the product. Cycle development balances shelf temperature, chamber pressure, and time. Scale-up can be difficult because heat and mass transfer change with equipment size, so process analytical tools and conservative validation are often used.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white porous cake | Color depends on formulation. |
| Typical storage temperature | 2–8 °C | Refrigerated for many biologics. |
| Residual moisture | <1% to 3% | Low moisture improves stability. |
| Container | Sealed glass vial | Often with rubber stopper and aluminum crimp. |
| Reconstitution time | Seconds to minutes | Varies with cake density and diluent. |
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.
Handling and storage practices aim to keep the cake intact and dry. Vials are typically stored upright at controlled temperatures, often between 2 °C and 8 °C or at -20 °C for longer-term use. Reconstitution involves adding a suitable diluent and gently mixing until the solid dissolves. Shaking or rapid injection of diluent can create foam or damage sensitive molecules. Once reconstituted, the product may require refrigeration and use within a defined period.
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.
Secondary drying removes bound water that remains after ice sublimation. Shelf temperature is raised gradually while pressure remains low, reducing water content to a target range. Over-drying can cause brittleness or electrostatic issues, while under-drying affects stability. The endpoint is often judged by pressure rise tests, temperature measurements, or water content analysis. Scale-up depends on matching heat and mass transfer across equipment sizes. Small changes in shelf temperature or pressure can alter cycle length substantially.
Lyophilization, or freeze-drying, removes water from a material by freezing it and then lowering pressure so ice changes directly to vapor. The process relies on sublimation, the phase transition from solid to gas without an intervening liquid state. It is used for heat-sensitive materials that would degrade in conventional drying. The three stages are freezing, primary drying, and secondary drying, each with distinct temperature and pressure requirements. In practice, cycle design balances these variables.
Freezing determines ice crystal structure and pore size, which affect drying speed and product uniformity. Rapid freezing creates small crystals, while slow freezing creates larger crystals and often faster sublimation. During primary drying, chamber pressure is held below the vapor pressure of ice, and shelf temperature supplies heat for sublimation. The ice front recedes, leaving a porous matrix. Thermal limits such as collapse and eutectic temperatures set safe boundaries for formulation. These limits vary with solute composition and concentration.
The related compound and Amanita species constituent ibotenic acid is a prodrug of muscimol, but also has neurotoxic effects. Muscimol was first isolated from Amanita muscaria and hence was discovered in 1964. It has been limitedly clinically studied as a potential pharmaceutical drug for a number of uses, such as treatment of epilepsy. In addition, analogues and derivatives of muscimol, such as the selective GABAA receptor agonist gaboxadol (THIP; LU-2-030) and the selective GABA reuptake inhibitor tiagabine (Gabitril), have been developed as pharmaceutical drugs. Muscimol and Amanita muscaria mushrooms have rarely been used as recreational drugs historically. By the mid-2020s however, use of these substances, including recreational use for hallucinogenic effects and microdosing for claimed therapeutic benefits, has become increasingly prominent. The most commonly cited therapeutic reason for their use is to improve sleep. Muscimol is not a controlled substance and is unregulated in most of the world, including in most of the United States and Europe.
=== 22 January === German Foreign Minister Annalena Baerbock stated that Germany would not stand in the way if Poland or other countries provide Leopard 2 tanks. Russian state media reported that Russian forces advanced into Orikhiv and Huliaipole towns in Zaporizhzhia Oblast.
=== Chronic wounds === A 2015 review found that the evidence supporting the use of electrotherapy in healing pressure ulcers was of low quality, and a 2015 Cochrane review found no evidence that electromagnetic therapy, a subset of electrotherapy, was effective in healing pressure ulcers. Earlier reviews found that, because of low-quality evidence, it was unclear whether electrotherapy increases healing rates of pressure ulcers. By 2014 the evidence supported electrotherapy's efficacy for ulcer healing. Another 2015 Cochrane review found no evidence supporting the use of electrotherapy for venous stasis ulcers.
Sources: en.wikipedia.org
In 1985, the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP) formed a Transfermium Working Group (TWG) to assess discoveries and establish final names for the controversial elements. The party held meetings with delegates from the three competing institutes; in 1990, they established criteria on recognition of an element, and in 1991, they finished the work on assessing discoveries and disbanded. These results were published in 1993. According to the report, the first definitely successful experiment was the April 1970 LBL experiment, closely followed by the June 1970 JINR experiment, so credit for the discovery of the element should be shared between the two teams. LBL said that the input from JINR was overrated in the review. They claimed JINR was only able to unambiguously demonstrate the synthesis of element 105 a year after they did. JINR and GSI endorsed the report. In 1994, IUPAC published a recommendation on naming the disputed elements. For element 105, they proposed joliotium (Jl) after the French physicist Frédéric Joliot-Curie, a contributor to the development of nuclear physics and chemistry; this name was originally proposed by the Soviet team for element 102, which by then had long been called nobelium. This recommendation was criticized by the American scientists for several reasons. Firstly, their suggestions were scrambled: the names rutherfordium and hahnium, originally suggested by Berkeley for elements 104 and 105, were respectively reassigned to elements 106 and 108.
Venezuela holds the world's largest proven oil reserves, estimated at 17% of the global total, or 300 billion barrels. In December 2025, the US began a maritime blockade of sanctioned oil or shadow fleet tankers. The 2025–2026 operations are seen by the Trump administration as serving the triple goals of crippling Maduro, disrupting drug trade routes, and getting access to Venezuelan oil; Trump stated that revenue generated would go to the Venezuelan people, US oil companies, and "to the United States of America in the form of reimbursement for the damages caused us by that country". Following the raid, Trump's press conference made clear that oil was a motivation for action in Venezuela. Citing the restructuring of Venezuela's oil industry in 1976 and 2007, Trump, Stephen Miller, and others claimed that Venezuela had stolen oil from US companies. Trump suggested on 5 January that seized oil could be treated as a US asset, asserting the willingness to sell it or add it to the US Strategic Petroleum Reserve. On 9 January, after other sanctioned vessels were seized, and a tanker was returned to Venezuela as part of a joint operation between interim authorities in Venezuela and the US, Trump said: "This tanker is now on its way back to Venezuela, and the oil will be sold through the GREAT Energy Deal, which we have created for such sales." The Trump administration also expressed interest in Venezuela's large deposits of gold and rare earth minerals.
== Works by Kenyon == Kenyon DH, Steinman G. Biochemical Predestination. McGraw Hill Text (1969) ISBN 0-07-034126-5. Davis PW, Kenyon DH. Of Pandas and People: The Central Question of Biological Origins. Foundation for Thought & Ethics; 2nd edition (1993) ISBN 0-914513-40-0. Steinman, G; Kenyon, DH; Calvin, M (August 1966). "The mechanism and protobiochemical relevance of dicyanamide-medicated peptide synthesis". Biochim. Biophys. Acta. 124: 339–50. PMID 5968904. Smith, AE; Kenyon, DH (1972). "Is life originating de novo?". Perspect. Biol. Med. 15: 529–42. PMID 5040075. Smith, AE; Kenyon, DH (July 1972). "The origin of viruses from cellular genetic material". Enzymologia. 43: 13–8. PMID 5050651. Smith, AE; Kenyon, DH (1973). "A unifying concept of carcinogenesis and its therapeutic implications". Oncology. 27 (5): 459–79. PMID 4578174. Smith, AE; Kenyon, DH (January 1973). "Acupuncture and A.T.P.: how they may be related". Am J Chin Med (Gard City N Y). 1: 91–7. PMID 4774360. Kenyon, DH (July 1975). "On terminology in origin of life studies". Orig. Life. 6: 447–9. PMID 1187108. Nissenbaum, A; Kenyon, DH; Oro, J (December 1975). "On the possible role of organic melanoidin polymers as matrices for prebiotic activity". J. Mol. Evol. 6: 253–70. PMID 1542. Kenyon, DH; Nissenbaum, A (April 1976). "Melanoidin and aldocyanoin microspheres: implications for chemical evolution and early precambrian micropaleontology". J. Mol. Evol. 7: 245–51. PMID 778393.
An osteocyte, an oblate-shaped type of bone cell with dendritic processes, is the most commonly found cell in mature bone. It can live as long as the organism itself. The adult human body has about 42 billion of them. Osteocytes do not divide and have an average half life of 25 years. They are derived from osteoprogenitor cells, some of which differentiate into active osteoblasts (which may further differentiate to osteocytes). Osteoblasts/osteocytes develop in mesenchyme. In mature bones, osteocytes and their processes reside inside spaces called lacunae (Latin for a pit) and canaliculi, respectively. Osteocytes are simply osteoblasts trapped in the matrix that they secrete. They are networked to each other via long cytoplasmic extensions that occupy tiny canals called canaliculi, which are used for exchange of nutrients and waste through gap junctions. Although osteocytes have reduced synthetic activity and (like osteoblasts) are not capable of mitotic division, they are actively involved in the routine turnover of bony matrix, through various mechanosensory mechanisms. They destroy bone through a rapid, transient (relative to osteoclasts) mechanism called osteocytic osteolysis. Hydroxyapatite, calcium carbonate and calcium phosphate is deposited around the cell.
Sources: en.wikipedia.org
=== Distribution === Met-enkephalin is found mainly in the adrenal medulla and throughout the central nervous system (CNS), including in the striatum, cerebral cortex, olfactory tubercle, hippocampus, septum, thalamus, and periaqueductal gray, as well as the dorsal horn of the spinal cord. It is also present in the periphery, notably in some primary afferent fibers that innervate the pelvic viscera.
== External links == Anorectics at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Mitchell, Kari (January 1997). "Anorexiant Agents: Considerations for Use" (PDF). Drug Therapy Topics. University of Washington Medical Center. Archived from the original (PDF) on 2013-12-26. Retrieved 25 December 2013.
1292–1319: Dame Péronelle, French herbalist. 13th century Shen Yu Hsiu, Chinese chemist. fl. 1300 Gilette de Narbonne, French physician. Giovanni Boccaccio wrote of her in ‘’The Decameron’’, calling her ‘Donna Medica’; Alfred Duru and Henri Chivot wrote a comic opera about her called Gillette de Narbonne. f. 1307 Trotta da Toya, Napolitan physician. fl. 1308 Francisca di Vestis, Napolian physician. fl. 1309 Maria Gallicia, licensed surgeon. fl. 1313–1325: Ameline la Miresse, French physician. fl. 1318–1324: Adelmota of Carrara was a physician in Padua, Italy. fl. 1318: Alessandra Giliani, Italian anatomist. 1320: Raymunda da Taberna, licensed Napolitan surgeon. fl. 1322: Fava of Manosque, French-Jewish physician. fl. 1322: Jacobina Félicie, Italian physician. fl. 1326: Sara de Sancto Aegidio, French physician. fl. 1326: Sarah de St Giles, French-Jewish physician and medical teacher. fl. 1333: Constanza, Italian surgeon, mentioned in Pope Sixtus IV edict regarding physicians and surgeons. fl. 1333: Francisca da Romana, Napolitan physician. fl. 1333: Isabella da Ocre, Napolitan surgeon. fl. 1333: Lauretta Ponte da Saracena Calabria, Napolitan physician. fl. 1333: Margarita da Venosa, licensed Napolitan surgeon, who studied at the University of Salerno She was considered a noteworthy practitioner and counted Ladislaus, king of Naples, as a patient. fl. 1333: Maria Incarnata, Italian surgeon, mentioned in Pope Sixtus IV edict regarding physicians and surgeons. fl. 1333: Sibyl of Benevento, Napolitan physician specializing in the plague buboes fl.
After neighbors reported the crime and named Karriem as a likely suspect, Karriem and wife Bertha (35) were arrested at 2729 Clinton street. In custody, Karriem admitted to the slayings. Karriem told police: "I had to kill somebody, I could not forsake my gods". Karriem reportedly told police "The ninth hour of the twentieth day had come Sunday. It was predestined 1,500 years ago that at that hour I must make a human sacrifice to my gods. It must not be a member of the Order of Islam." Karriem claimed Smith assented to the sacrifice, telling police "At first he didn't want to be killed, but when I showed him that he would be the saviour of the world and go to heaven right away, he said all right." Press on November 21 reported Karriem was the self-described "King" of a 100-member cult. Police initially suspected Karriem might be tied to the 1929 slaying of Benny Evangelista, whom press called a cult leader. Press ran a second story on the practice of Voodoo. Karriem explained "Smith was sitting in a chair in front of the altar. My wife was time-keeper. As the hour drew near, I said, 'Smith, do you still want to be killed?' because the command ordered me not to kill anybody who didn't want to be killed. Smith nodded his head. When it was just 12 o'clock, I said, 'Smith, get up and stand on the altar.' I grabbed my dirk (an eight-inch case knife) and stabbed him like this. Smith fell off the altar and started to groan and tried to get up.
=== Inducers === Many compounds commonly used in ferroptosis studies including erastin, RSL3 (RAS-selective lethal), ML162, and ML210 [from National Institutes of Health-Molecular Libraries Small Molecule Repository (NIH-MLSMR)] were initially identified in screens for compounds that can selectively kill cancerous mutant RAS cells. Initial studies characterized the mitochondrial VDAC2 and VDAC3 as the targets of erastin, though it was later found that the mechanistic target of erastin is the cystine/glutamate transporter system xc−. Erastin inhibits system xc−, lowering intracellular GSH levels. Consequently, the GSH-dependent GPX4 is unable to detoxify lipid hydroperoxide species, leading to ferroptotic cell death. Derivatives of erastin have been prepared to improve aqueous solubility, potency, and metabolic stability, with imidazole ketone erastin (IKE) being the most extensively studied. RSL3 and ML162 contain chloroacetamide moieties that can covalently react with nucleophilic residues. RSL3 and ML162 are able to bind to and inhibit GPX4 enzymatic activity or degrade GPX4 in lysate-based assays, though it has been found that RSL3 and ML162 do not inhibit purified GPX4 in vitro and target other selenoproteins such as thioredoxin reductase 1 (TXNRD1). However, other TXNRD1 inhibitors do not trigger ferroptosis, suggesting that TXNRD1 inhibition is not sufficient to trigger ferroptosis. The GPX4-inhibiting activity of RSL3 has also been suggested to be regulated by other factors such as 14-3-3ε or through broad targeting of the selenoproteome.
Sources: en.wikipedia.org
Lyophilized products should be stored in airtight containers, protected from moisture and light, at the temperature specified by the manufacturer. Many require refrigeration at 2–8 °C, while some need frozen storage. Always check the product label for specific conditions.
Moisture can cause the porous cake to collapse, increase molecular mobility, and accelerate chemical degradation. It may also promote microbial growth if the product lacks preservatives. Proper sealing and handling are essential to maintain stability.
Some formulations contain labile biological molecules that degrade even in the dry state at higher temperatures. Others have a low glass transition temperature, meaning the cake can soften or collapse at room temperature. Cold storage reduces molecular motion and slows degradation.
Yes, the terms are generally interchangeable. Lyophilization is more common in pharmaceutical and laboratory contexts, while freeze-drying appears widely in food science and general writing. Both describe removal of solvent by sublimation under vacuum after freezing.