Everything below concerns primary drying. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-12. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
After primary drying, secondary drying removes water that remains bound to the material. This stage raises the shelf temperature while maintaining low pressure, which encourages desorption of unfrozen water. Residual moisture can be reduced to a low percentage, improving stability for many products. The process parameters, including freezing rate, shelf temperature, and chamber pressure, influence the final pore structure and reconstitution behavior. Control of these variables helps prevent collapse or meltback during drying.
A formulation often contains excipients that protect the active ingredient during freezing and drying. Bulking agents provide structure, while lyoprotectants stabilize sensitive molecules. The freezing step can produce ice crystals whose size and distribution affect the drying rate, and cycle design includes freezing, annealing, and drying phases. If the product temperature rises above a critical value, the cake may collapse or lose its porous structure. Successful lyophilization therefore depends on the interaction between formulation, equipment, and cycle design.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | freeze-drying, lyophilisation, cryodesiccation | Lyophilization is common in pharmaceutical literature. |
| Typical chamber pressure during primary drying | 0.05–0.5 mbar (5–50 Pa) | Must remain below the triple point of water. |
| Typical shelf temperature during freezing | −40 to −20 °C | Lower temperatures may be used for eutectic systems. |
| Typical residual moisture after secondary drying | 0.5–3% w/w | Product-dependent; low moisture improves stability but can cause over-drying. |
| Typical analytical method for residual moisture | Karl Fischer titration or loss on drying | Thermogravimetric methods are also used. |
Industries use lyophilization for pharmaceuticals, biological products, and food preservation. In the pharmaceutical sector, it extends the shelf life of injectable drugs, vaccines, and proteins that are unstable in aqueous solution. Food manufacturers apply freeze-drying to coffee, fruits, and ready meals to retain flavor and texture. The process is energy-intensive and requires specialized equipment, which limits its use to high-value products. Ongoing research examines how formulation and process parameters affect the quality of the final dried product.
Lyophilization, also known as freeze-drying, is a process that removes water from a material by freezing it and then reducing pressure to allow ice to sublimate directly into vapor. The method begins with a freezing step that solidifies the water content. Next, primary drying lowers the pressure below the triple point of water, enabling sublimation without passing through a liquid phase. A final secondary drying step removes bound water through desorption. This sequence produces a dry, porous cake that can be reconstituted later.
The physics of lyophilization couples heat transfer, mass transfer, and phase behavior. Sublimation requires a vapor pressure difference between the ice front and the chamber, and the dried layer adds resistance to vapor flow. Amorphous formulations are characterized by a glass transition temperature of the maximally freeze-concentrated solute, often denoted Tg'. Crystalline bulking agents can provide structure, while amorphous excipients stabilize labile components. Open questions remain about spatial heterogeneity, edge effects, and how laboratory cycles scale to production.
Lyophilization is a drying process in which a solvent, usually water, is removed from a frozen material by sublimation under reduced pressure. The material is first solidified, then placed under vacuum so that ice transitions directly to vapor without a bulk liquid phase. This approach suits heat-sensitive substances that would degrade during conventional evaporation. Primary drying removes unbound ice, while secondary drying reduces water that remains adsorbed to the solid matrix. The result is a porous, lightweight solid that can be reconstituted later.
The physical chemistry of freezing influences whether a formulation forms an amorphous glass or a crystalline solid. Amorphous systems can collapse if product temperature rises above the glass transition temperature of the freeze concentrate. Crystalline systems may show eutectic melting, where ice and solute melt together at a fixed temperature. Formulators add bulking agents, lyoprotectants, and buffers to preserve structure and biological activity. The optimum cycle keeps product temperature below critical thresholds during primary drying while allowing efficient sublimation.
Lyophilization is a dehydration process that removes water from a frozen material by sublimation under low pressure. The material is first frozen so that water becomes ice; then the surrounding pressure is lowered below the vapor pressure of ice. Heat is applied gently so ice changes directly to vapor without passing through a bulk liquid phase. The vapor is collected on a cold condenser, leaving a dry porous matrix. This process differs from simple evaporation because the material remains frozen during the main drying stage.
The process usually has three stages: freezing, primary drying, and secondary drying. Freezing sets the ice crystal structure and can determine pore size in the final cake. Primary drying removes free ice by sublimation at low pressure and low shelf temperature. Secondary drying removes bound water by raising the shelf temperature, although some water may remain as part of the solid. Cycle parameters depend on formulation, fill volume, vial type, and equipment performance.
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.
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.
==== India ==== On February 24, 2011, Dunkin' Donuts signed a master franchise agreement with Indian food service company Jubilant FoodWorks to operate the brand in India. Jubilant FoodWorks opened the country's first Dunkin' Donuts outlet at Connaught Place, New Delhi in April 2012. In November 2014, Dunkin' Donuts opened its first store in Kanpur, Uttar Pradesh inside Z Square Mall. There were 32 Dunkin' Donuts outlets across 10 Indian cities as of December 31, 2019. On March 30, 2026, it was announced that Jubilant FoodWorks had decided not to renew development and operation agreements of Dunkin' Donuts in India. The agreement is to expire on December 31, 2026.
The Supreme Soviet (successor of the Congress of Soviets) was nominally the highest organ of state authority for most of the Soviet history, at first acting as a rubber stamp institution, approving and implementing all decisions made by the party. However, its powers and functions were extended in the late 1950s, 1960s, and 1970s, including the creation of new state commissions and committees. It gained additional powers relating to the approval of the Five-Year Plans and the government budget. The Supreme Soviet elected a Presidium (successor of the Central Executive Committee) to wield its power between plenary sessions, ordinarily held twice a year, and appointed the Supreme Court, the Procurator General and the Council of Ministers (known before 1946 as the Council of People's Commissars), headed by the Chairman (Premier) and managing an enormous bureaucracy responsible for the administration of the economy and society. State and party structures of the constituent republics largely emulated the structure of the central institutions, although the Russian SFSR, unlike the other constituent republics, for most of its history had no republican branch of the CPSU, being ruled directly by the union-wide party until 1990. Local authorities were organized likewise into party committees, local Soviets and executive committees. While the state was a de jure federation with a nominally federal constitution, the party was de facto centralized and unitary. The state security police (the KGB and its predecessor agencies) played an important role in Soviet politics.
== Public policy activities == • Coordination of the development of the health plans of Debrecen (2002, 2008) and Budapest (2012–2014) • Coordination of the strategic planning of the National Public Health Programme (2018–2030; 2023–2033) • Organisation and operation of the General Practitioners’ Morbidity Data Collection Programme (1998–2017) • Coordination of the establishment of the North‑East Hungarian Health Observatory (2005) • Coordination of the primary care development model programme based on general practitioners’ clusters, supported by the Hungarian Government and the Swiss Contribution (2012–2016), integrating primary care and public health services. She has led more than forty national research and educational development projects, including the major project “Improving the competitiveness of the Hungarian economy through identifying target groups and content of public health interventions to improve population health” (2016–2021), which resulted in 123 international publications and 32 completed PhD degrees. Her research groups have participated in more than twenty international projects, often under her leadership.
== Applications == NanoSIMS can capture the spatial variability of isotopic and elemental measurements of sub-micron areas, grains or inclusions from geological, materials science and biological samples. This instrument can characterise nanostructured materials with complex composition that are increasingly important candidates for energy generation and storage.
Sources: en.wikipedia.org
== Awards and honours == Dame Commander of the Order of the British Empire (DBE) for services to global diabetes, research, policy and care management (2026 Birthday Honours) Commander of the Order of the British Empire (CBE) for services to diabetes research (2016) Fellow of the Academy of Medical Sciences (2018) Outstanding Achievement in Clinical Diabetes Research Award, American Diabetes Association (2025)
Q-cytochrome c oxidoreductase is also known as cytochrome c reductase, cytochrome bc1 complex, or simply complex III. In mammals, this enzyme is a dimer, with each subunit complex containing 11 protein subunits, an [2Fe-2S] iron–sulfur cluster and three cytochromes: one cytochrome c1 and two b cytochromes. A cytochrome is a kind of electron-transferring protein that contains at least one heme group. The iron atoms inside complex III's heme groups alternate between a reduced ferrous (+2) and oxidized ferric (+3) state as the electrons are transferred through the protein. The reaction catalyzed by complex III is the oxidation of one molecule of ubiquinol and the reduction of two molecules of cytochrome c, a heme protein loosely associated with the mitochondrion. Unlike coenzyme Q, which carries two electrons, cytochrome c carries only one electron.
The resulting Treaty of Córdoba, which was signed on 24 August, kept all existing laws, including the 1812 Constitution, in force until a new constitution for Mexico could be written. O'Donojú became part of the provisional governing junta until his death on 8 October. Both the Spanish Cortes and Ferdinand VII rejected the Treaty of Córdoba, and the final break with the mother country came on 19 May 1822, when the Mexican Congress conferred the throne on Iturbide. Spain initiated attempts to reconquer Mexico and it did not recognize Mexico's independence until 1836. Central America gained its independence along with New Spain. On 15 September 1821, an Act of Independence was signed in Guatemala City which declared Central America (Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica) independent from Spain. The regional elites supported the terms of the Plan of Iguala and orchestrated the union of Central America with the Mexican Empire in January 1822. One years later, following Iturbide's downfall, the region, with the exception of Chiapas, peacefully seceded from Mexico on 1 July 1823, establishing the Federal Republic of Central America. The new state existed for seventeen years, centrifugal forces pulling the individual provinces apart by 1840.
Furthermore, exceptionally in this group, reactivity with boron decreases down the group: lithium reacts completely at 700 °C, but sodium at 900 °C and potassium not until 1200 °C, and the reaction is instantaneous for lithium but takes hours for potassium. Rubidium and caesium borides have not even been characterised. Various phases are known, such as LiB10, NaB6, NaB15, and KB6. Under high pressure the boron–boron bonding in the lithium borides changes from following Wade's rules to forming Zintl anions like the rest of group 13.
The product must be thujone-free as per TTB guidelines, The word "absinthe" can neither be the brand name nor stand alone on the label, and The packaging cannot "project images of hallucinogenic, psychotropic, or mind-altering effects". Absinthe imported in violation of these regulations is subject to seizure at the discretion of U.S. Customs and Border Protection.
Sources: en.wikipedia.org
Filtering helps stabilise the flavour of beer, holding it at a point acceptable to the brewer, and preventing further development from the yeast, which under poor conditions can release negative components and flavours. Filtering also removes haze, producing a clear beer with a "polished shine and brilliance". Clear beer became commercially desirable with the increasing use of glass drinking vessels and the development of pale lagers. During lagering, suspended material settles out, allowing the beer to "drop bright" and develop a naturally clear appearance. There are several forms of filters; they may be in the form of sheets or "candles", or they may be a fine powder such as diatomaceous earth (also called kieselguhr), which is added to the beer to form a filtration bed which allows liquid to pass, but holds onto suspended particles such as yeast. Filters range from rough filters that remove much of the yeast and any solids (e.g., hops, grain particles) left in the beer, to filters tight enough to strain colour and body from the beer. Filtration ratings are divided into rough, fine, and sterile. Rough filtration leaves some cloudiness and some character in the beer, while Fine filtration removes almost all cloudiness and microorganisms. Polysaccharides, proteins, yeast, bacteria and the brewing process may affect filtration.
==== Rivaroxaban ==== Rivaroxaban chemically belongs to the group of n-aryloxazolidinones. Other drugs of that group are linezolid and tedizolid, both of whom are antibiotics. A synthesis of n-aryloxazolidinones starting with an O-silyl protected ethyl(2,3-dihydroxypropyl)-carbamate was published in 2016. In a one-pot reaction the carbamate cyclisizes to a 2-oxazolidone ring under slightly basic conditions while simultaneously the oxazolidone nitrogen is arylized by copper-catalization. For rivaroxaban in particular, 3-morpholinone substitutes the iodine in p-position of the benzene ring by copper-catalization. Afterwards, the silyl protecting group is removed and the resulting alcohol is replaced by an amino group which is then acylated in the last step. An industrial preparation of rivaroxaban was registered as a patent by Bayer Healthcare in 2005. It starts from N-(4-aminophenol)-morpholinone which is alkylated by a propylene oxide derivate that also contains a primary amine involved in a phthalimide protection group. Next, a phosgene equivalent is added to form the 2-oxazolidone ring and the phthalimide is removed. The free amine can now be acylated which leads to rivaroxaban. However, according to the patent the synthesis has “various disadvantages in the reaction management which has particularly unfavourable effects for preparation“. The patent also explains another synthesis starting from a chlorothiophene derivate that would be more suitable for the industrial process but points out that toxic solvents or reagents have to be removed from the final product.
In modern terminology, Malay remains the name of an ethnoreligious group of Austronesian people predominantly inhabiting the Malay Peninsula and portions of the adjacent islands of Southeast Asia, including the east coast of Sumatra, the coast of Borneo, and smaller islands that lie between these areas. The state that gained independence from the United Kingdom in 1957 took the name the Federation of Malaya, chosen in preference to other potential names such as Malaysia and Langkasuka, after the historic kingdom located at the upper section of the Malay Peninsula in the first millennium CE. In 1963, the name Malaysia was adopted when the existing states of the Federation of Malaya, plus Singapore, North Borneo, and Sarawak, formed a new federation. One theory posits the name was chosen so that si represented the inclusion of Singapore, North Borneo, and Sarawak. Politicians in the Philippines contemplated renaming their state Malaysia before the modern country took the name.
== Food safety == In 2010, the U. S. Food and Drug Administration acknowledged high-purity quercetin as generally recognized as safe for use as an ingredient in various specified food categories at levels up to 500 mg per serving.
=== Speaking === Weakness of the muscles involved in speaking may lead to dysarthria and hypophonia. Speech may be slow and slurred, or have a nasal quality. In some cases, a singing hobby or profession must be abandoned.
Sources: en.wikipedia.org
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.
Reduced pressure keeps the process below the triple point of water, so ice can sublimate directly to vapor. It also lowers the temperature needed for drying, which helps preserve heat-sensitive materials. Without vacuum, melting or boiling could occur instead of controlled sublimation.
The rate depends on heat transfer to the product and mass transfer of vapor through the dried layer. A cold condenser, adequate vacuum, and suitable shelf temperature all influence speed. Formulation properties such as solid content and collapse temperature also set practical limits.
Lyophilization removes water by sublimation from a frozen material, while evaporation changes liquid water into vapor. The low-pressure freezing step avoids the liquid phase and can preserve heat-sensitive structures.