reconstitution raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-06-28 and is reviewed periodically as new material appears.
In practice, lyophilization is slower and more energy intensive than simple drying. Cycle times can range from hours to several days depending on load, container, and formulation. Amorphous materials may require excipients that help preserve structure during freezing and drying. The method is widely used for biological materials, pharmaceuticals, and foods where heat drying would cause unacceptable change. Open questions remain about scaling cycles between laboratory and production equipment, and this gap affects technology transfer.
Lyophilization removes water by freezing a material and then lowering pressure so ice changes directly to vapor. The process relies on sublimation, the phase transition from solid to gas without an intermediate liquid state. Because the material remains frozen during primary drying, the structure often stays porous. This porous matrix can rehydrate quickly when water is added back. The low pressure also allows vapor to leave the solid matrix without boiling.
A typical cycle begins with freezing, which fixes the material into a solid and determines ice crystal size. Primary drying then raises heat under vacuum so ice sublimes, often near or below the collapse temperature of the formulation. Secondary drying removes bound water that remains after ice is gone, usually by gently warming the product. Each stage balances heat input against pressure to avoid melting or structural damage. Temperature probes and pressure sensors guide the transition between stages.
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.
| Property | Value | Notes |
|---|---|---|
| Common synonym | Freeze-drying | Same dehydration operation |
| Typical vacuum | 10-100 Pa | Pressure during primary drying |
| Primary drying temperature | -40 to -10 °C | Below collapse temperature for many formulations |
| Cycle duration | 12-72 hours | Varies with load, container, and formulation |
| Key phase change | Sublimation | Solid ice to water vapor |
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.
Lyophilization is a dehydration process that removes water from a frozen material by sublimation under low pressure. The material is first frozen to convert liquid water into ice. Next, the pressure is reduced below the triple point of water so that ice changes directly into vapor without passing through a liquid phase. This step is called primary drying. The result is a porous solid or cake that retains the original shape of the frozen solution.
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.
The charge-to-mass ratio (Q/m) of an object is, as its name implies, the charge of an object divided by the mass of the same object. This quantity is generally useful only for objects that may be treated as particles. For extended objects, total charge, charge density, total mass, and mass density are often more useful. Derivation:
== Pharmacokinetics == The volume of distribution of Mobocertinib at steady state is 3,509 L. The mean oral bioavailability of Mobocertinib is 37%. The median Tmax is 4 hours. The average half-life of Mobocertinib and its metabolites is 18 hours. Mobocertinib is metabolized by CYP3A enzymes.
In an unrelated case, an almost fully developed uterus was found in a 22-year-old adult with CAIS. Other subtle differences that have been reported include slightly longer limbs and larger hands and feet due to a proportionally greater stature than unaffected women, larger teeth, minimal or no acne, well developed breasts, a greater incidence of meibomian gland dysfunction (i.e. dry eye syndromes and light sensitivity), and dry skin and hair resulting from a lack of sebum production.
In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the mobile phase, which carries it through a system (a column, a capillary tube, a plate, or a sheet) on which a material called the stationary phase is fixed. As the different constituents of the mixture tend to have different affinities for the stationary phase and are retained for different lengths of time depending on their interactions with its surface sites, the constituents travel at different apparent velocities in the mobile fluid, causing them to separate. The separation is based on the differential partitioning between the mobile and the stationary phases. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus affect the separation. Chromatography may be preparative or analytical. The purpose of preparative chromatography is to separate the components of a mixture for later use, and is thus a form of purification. This process is associated with higher costs due to its mode of production. Analytical chromatography is done normally with smaller amounts of material and is for establishing the presence or measuring the relative proportions of analytes in a mixture. The two types are not mutually exclusive.
== Medical use == Polymyxin antibiotics are relatively neurotoxic and nephrotoxic, so are usually used only as a last resort if modern antibiotics are ineffective or are contraindicated. Typical uses are for infections caused by strains of multiple drug-resistant Pseudomonas aeruginosa or carbapenemase-producing Enterobacteriaceae. Polymyxins have less effect on Gram-positive organisms, and are sometimes combined with other agents (as with trimethoprim/polymyxin) to broaden the effective spectrum. Polymyxins B are not absorbed from the gastrointestinal tract, so they are only administered orally if the goal is to disinfect the GI tract. Another route of administration is chosen for systemic treatment, e.g., parenteral (often intravenously) or by inhalation. They are also used externally as a cream or drops to treat otitis externa (swimmers ear), and as a component of triple antibiotic ointment to treat and prevent skin infections.
Sources: en.wikipedia.org
=== Gas adsorption chromatography precursors === German physical chemist Erika Cremer in 1947 together with Austrian graduate student Fritz Prior developed what could be considered the first gas chromatograph that consisted of a carrier gas, a column packed with silica gel, and a thermal conductivity detector. They exhibited the chromatograph at ACHEMA in Frankfurt, but nobody was interested in it. N.C. Turner with the Burrell Corporation introduced in 1943 a massive instrument that used a charcoal column and mercury vapors. Stig Claesson of Uppsala University published in 1946 his work on a charcoal column that also used mercury. Gerhard Hesse, while a professor at the University of Marburg/Lahn decided to test the prevailing opinion among German chemists that molecules could not be separated in a moving gas stream. He set up a simple glass column filled with starch and successfully separated bromine and iodine using nitrogen as the carrier gas. He then built a system that flowed an inert gas through a glass condenser packed with silica gel and collected the eluted fractions. Courtenay S.G Phillips of Oxford University investigated separation in a charcoal column using a thermal conductivity detector. He consulted with Claesson and decided to use displacement as his separating principle. After learning about the results of James and Martin, he switched to partition chromatography.
The culture of the Soviet Union evolved through several stages during its existence. During the first decade following the revolution, there was relative freedom and artists experimented with several different styles to find a distinctive Soviet style of art. Lenin wanted art to be accessible to the Russian people. On the other hand, hundreds of intellectuals, writers, and artists were exiled or executed, and their work banned, such as Nikolay Gumilyov who was shot for alleged conspiracy against the Bolsheviks, and Yevgeny Zamyatin. The government encouraged a variety of trends. In art and literature, numerous schools, some traditional and others radically experimental, proliferated. Communist writers Maxim Gorky and Vladimir Mayakovsky were active during this time. As a means of influencing a largely illiterate society, films received encouragement from the state, and much of director Sergei Eisenstein's best work dates from this period. During Stalin's rule, the Soviet culture was characterized by the rise and domination of the government-imposed style of socialist realism, with all other trends being severely repressed, with rare exceptions, such as Mikhail Bulgakov's works. Many writers were imprisoned and killed. Following the Khrushchev Thaw, censorship was diminished. During this time, a distinctive period of Soviet culture developed, characterized by conformist public life and an intense focus on personal life. Greater experimentation in art forms was again permissible, resulting in the production of more sophisticated and subtly critical work.
Emus begin to settle down at sunset and sleep during the night. They do not sleep continuously but rouse themselves several times during the night. When falling asleep, emus first squat on their tarsi and enter a drowsy state during which they are alert enough to react to stimuli and quickly return to a fully awakened state if disturbed. As they fall into deeper sleep, their neck droops closer to the body and the eyelids begin to close. If there are no disturbances, they fall into a deeper sleep after about twenty minutes. During this phase, the body is gradually lowered until it is touching the ground with the legs folded underneath. The beak is turned down so that the whole neck becomes S-shaped and folded onto itself. The feathers direct any rain downwards onto the ground. It has been suggested that the sleeping position is a type of camouflage, mimicking a small mound. Emus typically awake from deep sleep once every ninety minutes or so and stand upright to feed briefly or defecate. This period of wakefulness lasts for ten to twenty minutes, after which they return to slumber. Overall, an emu sleeps for around seven hours in each twenty-four-hour period. Young emus usually sleep with their neck flat and stretched forward along the ground surface.
== Adverse effects == Ten to forty percent of people will experience nausea, vomiting, abdominal pain, itching skin, increased body temperature, trembling and weakness. One to five percent of peoples may experience back and chest pain, dizziness, anemia, chills and sweating, metallic taste, tachycardia and respiratory distress. Contraindications for the use of carbetocin include inappropriate timing during labor and delivery (such as before parturition or to induce labor) or allergic reactions to carbetocin or other oxytocin homologues. Additionally, carbetocin should not be used if a person has high blood pressure or cardiovascular problems. Overdosage or repeated use of carbetocin, particularly if used during pregnancy, could cause hyper-excitation of the oxytocin receptors resulting in excessive and prolonged stimulation of uterine contractions, increasing risk of uterine rupture, placental abruption, fetal respiratory distress and postpartum hemorrhage.
Sources: en.wikipedia.org
==== 2019 ==== The lifespan of Caenorhabditis elegans (free-living nematodes) was increased by 5–6 times (by 400–500%) using simultaneous impact in IIS and TOR pathways. This is equivalent to how a human would live 400–500 years. The study was done by the MDI Biological Laboratory in collaboration with the Buck Institute for Research on Aging and Nanjing University. Scientists at the Mayo Clinic report the first successful use of senolytics, a new class of drug with potential anti-aging benefits, to remove senescent cells from human patients with a kidney disease. By combining doses of lithium, trametinib and rapamycin into a single treatment, researchers extend the lifespan of fruit flies (Drosophila) by 48%. Researchers at Harvard Medical School identify a link between neural activity and human longevity. Neural excitation is linked to shorter life, while suppression of overactivity appears to extend lifespan. Scientists at the Riken Center for Integrative Medical Sciences and Keio University use single-cell RNA analysis to find that supercentenarians have an excess of cytotoxic CD4 T-cells, a type of immune cell. This phenomenon was first demonstrated in mice
In structural biology, a protein subunit is a polypeptide chain or single protein molecule that assembles (or "coassembles") with others to form a protein complex. Large assemblies of proteins such as viruses often use a small number of types of protein subunits as building blocks. A subunit is often named with a Greek or Roman letter, and the numbers of this type of subunit in a protein is indicated by a subscript. For example, ATP synthase has a type of subunit called α. Three of these are present in the ATP synthase molecule, leading to the designation α3. Larger groups of subunits can also be specified, like α3β3-hexamer and c-ring. Naturally occurring proteins that have a relatively small number of subunits are referred to as oligomeric. For example, hemoglobin is a symmetrical arrangement of two identical α-globin subunits and two identical β-globin subunits. Longer multimeric proteins such as microtubules and other cytoskeleton proteins may consist of very large numbers of subunits. For example, dynein is a multimeric protein complex involving two heavy chains (DHCs), two intermediate chains (ICs), two light-intermediate chains (LICs) and several light chains (LCs). The subunits of a protein complex may be identical, homologous or totally dissimilar and dedicated to disparate tasks. In some protein assemblies, one subunit may be a "catalytic subunit" that enzymatically catalyzes a reaction, whereas a "regulatory subunit" will facilitate or inhibit the activity.
This is because the use of UV fluorescence is reagentless, or a process that does not require an added chemical to produce a reaction, with no consumables, or produces no chemical byproducts. Additionally, TAC-BIO can reliably discriminate between threat and non-threat aerosols. It was claimed to be sensitive enough to detect low concentrations, but not so sensitive that it would cause false positives. The particle-counting algorithm used in the device converted raw data into information by counting the photon pulses per unit of time from the fluorescence and scattering detectors, and comparing the value to a set threshold. The original TAC-BIO was introduced in 2010, while the second-generation TAC-BIO GEN II, was designed in 2015 to be more cost-efficient, as plastic parts were used. Its small, lightweight design allows it to be mounted to vehicles, robots, and unmanned aerial vehicles. The second-generation device could also be utilized as an environmental detector to monitor air quality in hospitals, airplanes, or even in households to detect fungus and mold.
Member, National Teaching School Council and Lead, South-West National Teaching School Council Representative. For services to Education. Chitralekha Bolar. Dancer, Choreographer and Teacher. For services to South Asian Dance. Emily Josephine Bolton. Founder, Our Future. For services to Social Mobility. Thomas Stewart Bosworth. For services to Race Walking. Richard James Bottomley. Headteacher, Bradford Alternative Provision Academy. For services to Vulnerable Children and Young People. James David Boyes. Team UK Gold Medal Winner, WorldSkills UK. For services to Further Education. Nicholas Boys Smith. Founder and Director, Create Streets and Chair, Office for Place. For services to Planning and Design. Samuel James Braddick. For services to the community in Gillingham, Dorset. Mark Richard Brett. For services to Charity and to the community in Wallingford, Oxfordshire. Anne Brewster. 50 Plus Lead, Yorkshire and the Humber, Department for Work and Pensions. For services to the Welfare of Older People. Debbie Hazel Brown. Advanced Nurse Practitioner and Clinical Director, Lewisham Community Education Provider Network Training Hub. For services to Nursing and the NHS. Joanna Esther Brown (Joanna Cram). Lately Chair, Scottish Osteopathic Society. For services to Musculoskeletal Healthcare in Scotland. Patricia Ann Brown. Director and Founder, Central. For services to the Built Environment. Penelope Jane Brown. For services to Charity and to the community in Salisbury, Wiltshire. Sara Margaret Browne (Sally Browne).
In September 2010, Labcorp acquired Genzyme Genetics, formerly a division of Genzyme Corporation, with 9 testing laboratories and approximately 1,900 employees, for $925 million in cash. In February 2011, Labcorp acquired the assets of bankrupt Westcliff Medical Laboratory. The FTC challenged the acquisition but lost in court. In June 2011, Labcorp acquired Canadian central labs partner Clearstone from Czura Thornton, adding laboratories in China, France, Singapore and Canada, and the central laboratory protocol management system APOLLO CLPM. In November 2011, Labcorp acquired more than 90% of the shares of DNA testing company Orchid Cellmark for $85 million. To receive approval of the transaction from the Federal Trade Commission, Labcorp sold parts of Orchid's DNA paternity testing business to DNA Diagnostics Center. In May 2012, Labcorp Clinical Trials sold its European biological sampling kit building operation located in Hamburg to Marken. In August 2012, Labcorp acquired testing lab Medtox Scientific for $241 million. In September 2013, Labcorp acquired MuirLab, the clinical laboratory outreach business of John Muir Health. In November 2014, Labcorp acquired LipoScience, a developer of diagnostic tests based on nuclear magnetic resonance spectroscopy measuring heart disease risk, for $85 million. In December 2014, Labcorp acquired Bode Technology Group, a provider of forensic DNA analysis, DNA collection products, and relationship testing and the largest DNA forensic testing company in the U.S., from SolutionPoint International.
Sources: en.wikipedia.org
Primary drying removes ice by sublimation under vacuum. Secondary drying removes water that is bound to the material, often by warming the product after most ice has left. Both stages occur below temperatures that would cause unwanted melting.
Sublimation requires the solvent to remain solid so vapor leaves without passing through a liquid phase. If the product melts, the porous structure can collapse and drying becomes uneven. Maintaining frozen conditions preserves the intended physical form.
No, freeze-drying is a dehydration method, not a sterilization step. It can reduce water activity and limit microbial growth during storage, but it does not reliably kill microbes or remove endotoxins. Sterility must come from separate validated processes.
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.