Sublimation raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-17. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary phase change | Sublimation | Ice changes directly to vapor under reduced pressure |
| Typical chamber pressure | 0.01–0.5 mbar (1–50 Pa) | Below the triple point of water; product-specific |
| Typical product temperature during primary drying | −40 °C to −10 °C | Kept below collapse temperature |
| Typical residual moisture | 0.5–3% w/w | Target range varies by formulation and use |
| Common synonyms | Freeze-drying; lyophilisation | Lyophilization is the US spelling |
Americold Realty Trust, Inc. is an American temperature controlled warehousing and transportation company based in Atlanta, Georgia, United States. It is in the business of modern commercialized temperature controlled warehousing for the storage of perishable goods via a cold chain, one of the forms of food preservation. Americold is the 2nd largest temperature-controlled warehousing and distribution services provider in the world.
==== Uses ==== As mentioned in the section Pathway systems, there were several uses for the Inca roads. The most obvious way in which the Inca people used the road/trail systems was to transport goods. They did this on foot and sometimes with the help of animals (llamas and alpacas). Not only were goods transported throughout the vast empire, but so were ideas and messages. The Inca needed a system of communication, so they relied on Chasquis, otherwise known as messengers. The Chasquis were chosen among the strongest and fittest young males. They ran several miles per day, only to deliver messages. These messengers resided in cabins called "tambos." These structures were positioned along the roads and built by the Inca people. These buildings provided the Chasquis with a place to rest. These places of rest could also be used to house the Inca army in a situation of rebellion or war.
Along with pancuronium bromide and potassium chloride, thiopental is used in 34 US states to execute prisoners by lethal injection. A large dose is given to ensure rapid loss of consciousness. Although death usually occurs within ten minutes of the beginning of the injection process, some have been known to take longer. In December 2009, Ohio became the first state in the US to use a single dose of sodium thiopental for an execution, following the failed use of the standard three-drug cocktail during a prior execution, due to inability to locate suitable veins. Kenneth Biros was executed using the single-drug method. Washington became the second state in the US to use the single-dose sodium thiopental injections for executions. In September 2010, the execution of Cal Coburn Brown was the first in the state to use a single-dose, single-drug injection. His death was pronounced approximately one and a half minutes after the intravenous administration of five grams of the drug. After its use for the execution of Jeffrey Landrigan in the US, the United Kingdom introduced a ban on the export of sodium thiopental in December 2010, after it was established that no European supplies to the US were being used for any other purpose. The restrictions were based on "the European Union Torture Regulation (including licensing of drugs used in execution by lethal injection)".
Most LFTs are intended to operate on a purely qualitative basis. However, it is possible to measure the intensity of the test line to determine the quantity of analyte in the sample. Handheld diagnostic devices known as lateral flow readers are used by several companies to provide a fully quantitative assay result. By utilizing unique wavelengths of light for illumination in conjunction with either CMOS or CCD detection technology, a signal-rich image can be produced of the actual test lines. Using image processing algorithms specifically designed for a particular test type and medium, line intensities can then be correlated with analyte concentrations. One such handheld lateral flow device platform is made by Detekt Biomedical L.L.C. Alternative non-optical techniques are also able to report quantitative assays results. One such example is a magnetic immunoassay (MIA) in the LFT form also allows for getting a quantified result. Reducing variations in the capillary pumping of the sample fluid is another approach to move from qualitative to quantitative results. Recent work has, for example, demonstrated capillary pumping with a constant flow rate independent from the liquid viscosity and surface energy.
Sources: en.wikipedia.org
=== Return to Essendon Football Club (2010–2014) === On 10 November 2010, Thompson signed a lucrative contract to return to Essendon as the senior assistant coach under senior coach James Hird, putting an end to weeks of speculation following his resignation from Geelong. According to football writer and commentator Caroline Wilson's sources, his contract was said to be worth $650,000 per year. He was appointed the senior coach for the 2014 season while James Hird served his suspension, and left the club after Hird returned as senior coach at the end of that year.
===== Adverse effects ===== Common adverse effects elicited by these drugs include hot flushes, bone loss, headache, unpredictable mood changes, depression, vaginal dryness, or even atrophy for females and penile atrophy for males. These adverse effects can be counteracted and treated by add-back therapy, also known as hormone replacement therapy. People treated with GnRH agonists are suggested to undergo this therapy simultaneously by taking adequate progestin, vitamin D, and calcium supplement pills daily.
Recent studies have detected the presence of significant levels of dioxins in the commercial shrimp Aristeus antennatus and significant levels of persistent organic pollutants in mesopelagic and bathypelagic cephalopods. Climate-driven processes and climate change will affect the frequency and intensity of cascading, with unknown effects on the benthic fauna. Another potential effect of climate change is related to energy transport from surface waters to the seafloor. Primary production will change in the surface layers according to sun exposure, water temperature, major stratification of water masses, and other effects, and this will affect the food chain down to the deep seafloor, which will be subject to differences in quantity, quality, and timing of organic matter input. As commercial fisheries move into deeper waters, all of these effects will affect the communities and populations of organisms in cold seeps and the deep sea in general.
=== 1950s job losses === In the postwar period, the city had lost nearly 150,000 jobs to the suburbs. Factors were a combination of changes in technology, increased automation, auto industry consolidation, taxation policies, the need for different kinds of manufacturing space, and the highway system construction that eased commuter transportation. Major companies like Packard, Hudson, and Studebaker, as well as hundreds of smaller companies, declined significantly or went out of business entirely. In the 1950s, the unemployment rate hovered near 10 percent.
==== Empyema ==== Untreated cholecystitis can lead to worsened inflammation and infected bile that can lead to a collection of pus inside the gallbladder, also known as empyema. The symptoms of empyema are similar to uncomplicated cholecystitis but greater severity: high fever, severe abdominal pain, more severely elevated white blood count.
Sources: en.wikipedia.org
Light oils (turpentine): Oils lighter than water that rise to the top. Pitch or tar: The heavy, nearly solid residue left at the bottom. Heavy oils (creosote): These are the "oils heavier than water." This specific fraction is the medical or industrial creosote, valued for its preservative and antiseptic properties.
== External links and resources == "Cold Chain Management", 2003, 2006, [1] Brody, A. L., and Marsh, K, S., "Encyclopedia of Packaging Technology", John Wiley & Sons, 1997, ISBN 0-471-06397-5 Lockhart, H., and Paine, F.A., "Packaging of Pharmaceuticals and Healthcare Products", 2006, Blackie, ISBN 0-7514-0167-6
More than 650,000 Americans have died of drug overdoses since the opioid epidemic began. The deaths attributable to opioid overdose increased from 16 deaths to 595 deaths per 100,000 population in the US.
Charles River Laboratories International, Incorporated is an American life sciences company and contract research organisation (CRO) headquartered in Wilmington, Massachusetts, United States. Founded in 1947, the company provides goods and services that support the development of drugs, vaccines, and other therapeutics. Its operations span at least 20 countries, offering research models, drug discovery and safety assessment, and manufacturing and testing services to pharmaceutical, biotechnology, government, and other clients. Charles River Laboratories is a global provider of non-clinical drug development services, known for its role in toxicology studies, research animal models, and microbial testing services used in regulatory submissions to health authorities such as the U.S. Food and Drug Administration (FDA). The company has also been the subject of public scrutiny and regulatory attention over its use of research animals, including dogs, primates, and horseshoe crabs. As of 2024, the company employs over 20,000 people worldwide and is publicly traded on the New York Stock Exchange under the ticker symbol CRL.
The String Synthesis introduced by Furka et al. uses stringed macroscopic solid support units (crowns) and the units are identified by their position occupied on the string. One string is assigned for every building block in the synthesis. In the coupling stage, the string is in the proper reaction vessel. The content of the strings coming out from a synthetic step must be redistributed into the strings of the next step. The units are not pooled. The redistribution demonstrated in the figure follows the combinatorial distribution rule: all products formed in a synthetic step are equally divided among all reaction vessels of the next synthetic step. Different distribution formats can be followed that allows the identification the content of each crown depending on the position on the new string and the destination reaction vessel of the string.
Sources: en.wikipedia.org
Lyophilization relies on sublimation, so water moves from solid ice to vapor without becoming liquid. The material is frozen, pressure is reduced, and controlled heat is supplied. Vapor is captured on a cold condenser, leaving a dry porous solid.
The process has three main stages: freezing, primary drying, and secondary drying. Freezing sets the ice structure, primary drying removes free ice, and secondary drying removes bound water. Each stage uses specific temperature, pressure, and time settings.
No, it is a drying method rather than a sterilization method. Removing water can limit microbial growth, but it does not reliably kill microorganisms. Sterility must come from separate steps such as filtration, heat treatment, or aseptic processing.
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.