The short version of Sublimation fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-28. Anything still debated is marked as such rather than presented as settled.
Quality control for lyophilized products includes appearance, cake structure, reconstitution time, pH, residual moisture, and potency. Residual moisture is a key attribute because excess water can reduce stability, while excessively low moisture may cause structural changes or aggregation in some systems. Stability studies compare real-time and accelerated conditions to estimate shelf life. Analytical methods must be validated for the specific matrix, container, and moisture range. Sterility and container integrity are also monitored for sterile products.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical appearance | White to off-white porous cake or powder | Color and structure vary with formulation. |
| Typical reconstitution time | Seconds to several minutes | Diluent, agitation, and temperature affect rate. |
| Typical storage temperature | 2–8 °C, 15–25 °C, or ≤−20 °C | Product-specific; protect from moisture and light. |
| Typical container closure | Glass vial with rubber stopper and crimp seal | Closure must limit moisture ingress. |
| Typical stability indicator | Residual moisture, potency, and reconstitution time | Monitored throughout shelf life. |
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.
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.
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.
Lyophilized products are typically hygroscopic and require protection from moisture during storage. Manufacturers seal them in glass vials, often under vacuum or an inert gas such as nitrogen. The container closure system, including the stopper and crimp seal, must prevent water vapor ingress. Storage temperature varies from controlled room temperature to refrigerated or frozen conditions, depending on the formulation. Humidity-controlled environments are essential because even brief exposure to ambient air can degrade the product.
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.
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.
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.
Tellurium-128 and -130 are essentially stable. They only decay by double beta decay, with half-lives >1020 years. They constitute the major fraction of natural occurring tellurium at 32 and 34% respectively. Tellurium-132 and its daughter 132I are important in the first few days after a criticality. It was responsible for a large fraction of the dose inflicted on workers at Chernobyl in the first week. The isobar forming 132Te/132I is: Tin-132 (half-life 40 s) decaying to antimony-132 (half-life 2.8 minutes) decaying to tellurium-132 (half-life 3.2 days) decaying to iodine-132 (half-life 2.3 hours) which decays to stable xenon-132. The creation of tellurium-126 is delayed by the long half-life (230 k years) of tin-126.
=== Pharmacokinetics === The half-life of endogenous insulin once it enters the bloodstream is 4 to 6 minutes. This allows the endocrine system to rapidly adapt to changing conditions within the body. Exogenous insulin, however, would not be effective with a short half-life, as it would require continuous injection or infusion to have the desired effect. While it is difficult to change the rate at which the protein is metabolized in the bloodstream, it is possible to alter how fast the protein is absorbed from the site of injection in various ways. Lente insulin was formulated by the addition of zinc to the crude porcine and bovine insulin extracts, which causes the insulin protein to form larger crystals which dissolve into the body slower upon injection. This means that while the insulin in the bloodstream is still metabolized in 4–6 minutes, more insulin is continually being absorbed from the dose injected for hours after administration. Compared to NPH insulin, another intermediate acting insulin, up to 40% of the dose of lente insulin may remain unabsorbed for over 24 hours after administration. The variation in absorption between doses in the same patient of lente insulin is comparable to that of insulin NPH. The distribution of insulin is not well understood, but it is known that it is heavily bound to receptors throughout the body (approximately 80% to receptors on liver cells) and metabolized in large part by phase one processes in the liver.
== External links == Kavkaz-2008 leaflet ("Soldier, know your probable enemy"), The Guns of August 2008: Russia's War in Georgia, p. xi - xii Anna Nemtsova, Q&A: Georgia's Mikheil Saakashvili on Russia Fight, Newsweek, 11 August 2008 William Rees-Mogg, Georgia: another Sarajevo moment avoided, The Times, 11 August 2008 Illarionov: Russia Lost the Georgian War, The Other Russia, 13 August 2008 (in Russian) "We Will never surrender", Der Spiegel, 18 August 2008 (in Russian) Vadim Rechakolv's comment on the movement of Russian tank column through the Roki Tunnel on 7 August Denis Macshane, Denis MacShane Explores the Myths About Russia, Newsweek, 5 September 2008 Ministry of Foreign Affairs of Georgia, Media and telephone intercepts confirm Russia started the war, 20 September 2008 (in Russian) André Glucksmann, Putin's doctrine, 22 October 2008 The Government of Georgia, Factual Evidence Contradicts War Claims in Recent Media Stories;, 18 November 2008 Bear on the Prowl? The Return of Russia as a Great Power Archived 17 March 2024 at the Wayback Machine; Australian Institute of International Affairs, November 2008 Julia Latynina - Articles on August war (Translations) Report by the Government of Georgia on the aggression by the Russian Federation against Georgia, 7 August 2009. PDF file. (in Russian) Grani TV, Andrei Nekrasov, Movie director, Garry Kasparov about "Russian Lessons", 14 September 2009 Caucasus Analytical Digest No.
Food and Drug Administration Food hygiene: example Clinical laboratory medicine: ISO 15198:2004 Clinical laboratory medicine—In vitro diagnostic medical devices—Validation of user quality control procedures by the manufacturer Engineering Engineering in general Engineering validation test Civil engineering Buildings – Roads – Bridges – Health care: example Greenhouse gas: ISO 14064 ANSI/ISO: Greenhouse gases – Requirements for greenhouse gas validation and verification bodies for use in accreditation or other forms of recognition Traffic and transport Road safety audit Periodic motor vehicle inspection Aircraft noise: example Aircraft: Model: (Ni-Cd) cells: example ICT Industry: example Accounting Agriculture – applications vary from verifying agricultural methodology and production processes to validating agricultural modeling Real estate appraisal – audit reporting and authentication Arms control
=== Legal status === Unlike many other opioids, nalbuphine has a limited potential for euphoria, and in accordance, is rarely abused. This is because whereas MOR agonists produce euphoria, MOR antagonists do not, and KOR agonists like nalbuphine moreover actually produce dysphoria. Nalbuphine was initially designated as a Schedule II controlled substance in the United States along with other opioids upon the introduction of the 1970 Controlled Substances Act. However, its manufacturer, Endo Laboratories, Inc., petitioned the Food and Drug Administration to remove it from Schedule II in 1973, and after a medical and scientific review, nalbuphine was removed completely from the Controlled Substances Act in 1976 and is not a controlled substance in the United States today. For comparison, MOR full agonists are all Schedule II in the United States, whereas the mixed KOR and MOR agonists/antagonists butorphanol and pentazocine are Schedule IV in the United States. In Canada, most opioids are classified as Schedule I, but nalbuphine and butorphanol are both listed as Schedule IV substances.
Sources: en.wikipedia.org
This is particularly so considering that bicalutamide increases circulating testosterone levels, and by extension gonadal testosterone production, by up to two-fold in males, and that only a small fraction of normal intratesticular testosterone levels, and by extension androgen action, appears to be necessary to maintain spermatogenesis. Bicalutamide monotherapy at 50 mg/day causes no or clinically unimportant Leydig cell hyperplasia. In contrast to bicalutamide and other pure antiandrogens or NSAAs, antigonadotropic antiandrogens suppress gonadotropin secretion, which in turn diminishes testosterone production by the testes as well as the maintenance of the testes by FSH, resulting in atrophy and loss of their function. As such, bicalutamide and other NSAAs may uniquely have the potential to preserve testicular function and spermatogenesis and thus male fertility relative to alternative therapies. In accordance with this notion, a study found that prolonged, high-dose bicalutamide treatment had minimal effects on fertility in male rats. However, another study found that low-dose bicalutamide administration resulted in testicular atrophy and reduced the germ cell count in the testes of male rats by almost 50%, though the rate of successful fertilization and pregnancy following mating was not assessed. Additional studies found that bicalutamide decreased testes weights, altered testes histology, and decreased sperm count in male rats. Yet another study found that bicalutamide has no effect on testes weights or spermatogenesis in male rats.
=== DPP-4 inhibitor trials === McGuire served on the executive committees of four cardiovascular outcome trials (CVOTs) evaluating DPP-4 inhibitors: SAVOR-TIMI 53 (saxagliptin), TECOS (sitagliptin), CAROLINA (linagliptin), and CARMELINA (linagliptin). He was co-chair of CARMELINA. These trials were designed to establish non-inferiority for major adverse cardiovascular events (MACE). SAVOR-TIMI 53 reported an increased risk of hospitalization for heart failure with saxagliptin.
=== Muchik linguistic evidence and Moche consumption === During the pre-Columbian era, the Moche culture (or Mochica), which inhabited the northern coast of Peru, actively collected and consumed the fruits of Solanum pimpinellifolium. Unlike the common domesticated tomato (Solanum lycopersicum), which lacks native names of Andean origin because its final domestication occurred in Mesoamerica, S. pimpinellifolium was integrated early into the local lexicon of the region. In the ancient Muchik language, the plant and its fruit were called faña (translated as "tender plant"), a designation recovered in modern philological research on the pre-Hispanic speech of the area.
The properties of many polymers are affected by hydrogen bonds within and/or between the chains. Prominent examples include cellulose and its derived fibers, such as cotton and flax. In nylon, hydrogen bonds between carbonyl and the amide NH effectively link adjacent chains, which gives the material mechanical strength. Hydrogen bonds also affect the aramid fibre, where hydrogen bonds stabilize the linear chains laterally. The chain axes are aligned along the fibre axis, making the fibres extremely stiff and strong. Hydrogen-bond networks make both polymers sensitive to humidity levels in the atmosphere because water molecules can diffuse into the surface and disrupt the network. Some polymers are more sensitive than others. Thus nylons are more sensitive than aramids, and nylon 6 more sensitive than nylon-11.
Octopuses appear in mythology as sea monsters such as the kraken of Norway and the Akkorokamui of the Ainu, and possibly the Gorgons of ancient Greece. A battle with an octopus appears in Victor Hugo's book Toilers of the Sea. Octopuses appear in Japanese shunga erotic art. They are eaten and considered a delicacy by humans in many parts of the world, especially the Mediterranean and Asia.
Sources: en.wikipedia.org
== Related enzymes == Prophenoloxidase is a modified form of the complement response found in some invertebrates, including insects, crabs and worms. Hemocyanin is homologous to the phenol oxidases (e.g. tyrosinase) since both enzymes sharing type copper active site coordination. Hemocyanin also exhibits PPO activity, but with slowed kinetics from greater steric bulk at the active site. Partial denaturation actually improves hemocyanin's PPO activity by providing greater access to the active site. Aureusidin synthase is homologous to plant polyphenol oxidase, but contains certain significant modifications. Aurone synthase catalyzes the formation of aurones. Aurone synthase purified from Coreopsis grandiflora shows weak tyrosinase activity against isoliquiritigenin, but the enzyme does not react with the classic tyrosinase substrates l-tyrosine and tyramine and must therefore be classified as catechol oxidase. Laccase, a multi-copper oxidase, is often considered a subclass of polyphenol oxidase. Laccase and polyphenol oxidase differ in the type of substrates that they catalyse. Catachol oxidase (a type of polyphenol oxidase) catalyses the oxidation of ortho-diphenols to ortho-quinones. Tyrosinase (another type of polyphenol oxidase), catalyses both the oxidation of monophenols to ortho-diphenols, and the subsequent oxidation of ortho-diphenols to ortho-quinones. Laccase, in contrast, catalyses the oxidation of para-diphenols to para-quinones.
The partition coefficient between n-Octanol and water is known as the n-octanol-water partition coefficient, or Kow. It is also frequently referred to by the symbol P, especially in the English literature. It is also known as n-octanol-water partition ratio. Kow, being a type of partition coefficient, serves as a measure of the relationship between lipophilicity (fat solubility) and hydrophilicity (water solubility) of a substance. The value is greater than one if a substance is more soluble in fat-like solvents such as n-octanol, and less than one if it is more soluble in water.
The final step in the first ubiquitylation event is an attack from the target protein lysine amine group, which will remove the cysteine, and form a stable isopeptide bond. One notable exception to this is p21 protein, which appears to be ubiquitylated using its N-terminal amine, thus forming a peptide bond with ubiquitin.
== Exact solutions of the Navier–Stokes equations == Some exact solutions to the Navier–Stokes equations exist. Examples of degenerate cases—with the non-linear terms in the Navier–Stokes equations equal to zero—are Poiseuille flow, Couette flow and the oscillatory Stokes boundary layer. But also, more interesting examples, solutions to the full non-linear equations, exist, such as Jeffery–Hamel flow, Von Kármán swirling flow, stagnation point flow, Landau–Squire jet, and Taylor–Green vortex. Time-dependent self-similar solutions of the three-dimensional non-compressible Navier–Stokes equations in Cartesian coordinate can be given with the help of the Kummer's functions with quadratic arguments. For the compressible Navier–Stokes equations the time-dependent self-similar solutions are however the Whittaker functions again with quadratic arguments when the polytropic equation of state is used as a closing condition. Note that the existence of these exact solutions does not imply they are stable: turbulence may develop at higher Reynolds numbers. Under additional assumptions, the component parts can be separated.
Sources: en.wikipedia.org
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.
Karl Fischer titration is a common method, along with loss on drying and thermogravimetric analysis. Each method has different sensitivity and sample requirements. Results should be interpreted with the product's formulation and container in mind.
No. Lyophilization removes water but is not a sterilization step. Sterile products are typically filtered and filled aseptically before freezing, and container closure integrity is maintained afterward.
Conventional drying uses heat to evaporate liquid water, often at temperatures that can degrade sensitive materials. Lyophilization freezes the material first and then removes water by sublimation under vacuum. This avoids prolonged exposure to liquid water and high heat.