intranasal delivery 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 2025-12-31. Where a claim depends on a specific study, the study is described rather than over-claimed.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Identity and purity are established with standard peptide methods. Reversed-phase HPLC with ultraviolet detection near 214 nm resolves the parent peak from deletion and truncation byproducts, and reports typically quote a main-peak percentage. Mass spectrometry by electrospray or MALDI-TOF confirms the expected molecular mass, while amino acid analysis or peptide mapping can verify composition when the sequence itself is in question. A certificate of analysis that pairs a chromatogram with a mass spectrum is more informative than a purity figure alone. Counter-ion content and residual solvents are separate specifications and are frequently omitted.
Semax is normally supplied as a lyophilized powder, and that form is the most stable. Suppliers commonly recommend storage at -20 °C in a desiccated container protected from light, with short-term handling at room temperature limited to weighing and transfer. Powder that has absorbed moisture degrades faster, so vials should be warmed to ambient temperature before opening to prevent condensation on the contents. Hygroscopic behavior is typical of short hydrophilic peptides, and humidity control matters more than temperature alone for long-term retention.
| Property | Value | Notes |
|---|---|---|
| Primary research models | Rodent studies | Largest share of published data |
| Reported markers | BDNF and NGF expression | Measured mainly in animal tissue |
| Common administration | Intranasal | Matches the registered formulation |
| Blood residence time | Minutes | Rapid enzymatic degradation |
| Evidence quality | Small trials, limited replication | Noted repeatedly in reviews |
常规纯度与身份确认依赖反相高效液相色谱，并辅以质谱测定分子量。氨基酸组成分析可用于验证序列构成，肽图分析则能进一步定位修饰或降解产物。杂质谱通常关注缺失序列肽、截短片段和氧化产物。不同方法的检出限并不相同，因此各实验室报告的纯度数值不宜直接横向比较。
多数实验室与市售的 Semax 以冻干粉形式提供。冻干粉通常建议保存在 -20 °C 或更低温度下，同时避免光照与反复升温。短期运输有时采用冷藏条件，但长期保存仍以冷冻为主。分包操作应尽量减少开盖次数，以降低吸湿和微生物污染的风险。开封后若未一次用完，建议在干燥环境中密封并尽快放回低温储存。
溶液状态的稳定性明显低于冻干粉。肽类在水溶液中可能经历水解、氧化与聚集，其中甲硫氨酸和天冬酰胺等残基常是敏感位点。Semax 含有甲硫氨酸，因此氧化风险相对突出。工作液一般主张现配现用，或冷藏并在数日内用尽。缓冲液种类、pH 和离子强度都会影响降解速率，而关于最佳条件的公开数据并不统一。
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
Routine characterization relies on reversed-phase high-performance liquid chromatography to establish purity and on mass spectrometry to confirm molecular identity. Electrospray ionization and matrix-assisted laser desorption ionization are both used for mass verification. Amino acid analysis and peptide mapping can detect sequence errors. Common impurities include truncated sequences, methionine sulfoxide formed by oxidation, and deamidated products. Chromatograms are usually recorded near 214 nm, where the peptide backbone absorbs, and purity is reported as the percentage area of the principal peak.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
稳定性主要由水解与氧化两条路径支配。肽键在中性或弱酸性条件下相对稳定，遇到强碱或长时间高温则明显断裂；甲硫氨酸侧链容易被氧化成亚砜，使主峰前移并拉低实际含量。金属离子、光照和反复冻融会进一步促进降解或聚集。冻干粉在低温避光条件下可存放较长时间，配制后的水溶液通常需要冷藏并尽快用完。
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
=== Intravenous fluids === In those with poor tissue perfusion, boluses of isotonic crystalloid solution should be given. In children with more than 10–20% TBSA (Total Body Surface Area) burns, and adults with more than 15% TBSA burns, formal fluid resuscitation and monitoring should follow. This should be begun pre-hospital if possible in those with burns greater than 25% TBSA. The Parkland formula can help determine the volume of intravenous fluids required over the first 24 hours. The formula is based on the affected individual's TBSA and weight. Half of the fluid is administered over the first 8 hours, and the remainder over the following 16 hours. The time is calculated from when the burn occurred, and not from the time that fluid resuscitation began. Children require additional maintenance fluid that includes glucose. Additionally, those with inhalation injuries require more fluid. While inadequate fluid resuscitation may cause problems, over-resuscitation can also be detrimental. The formulas are only a guide, with infusions ideally tailored to a urinary output of >30 mL/h in adults or >1mL/kg in children and mean arterial pressure greater than 60 mmHg. While lactated Ringer's solution is often used, there is no evidence that it is superior to normal saline. Crystalloid fluids appear just as good as colloid fluids, and as colloids are more expensive they are not recommended. Blood transfusions are rarely required. They are typically only recommended when the hemoglobin level falls below 60-80 g/L (6-8 g/dL) due to the associated risk of complications.
Governments have the primary public health mandate of ensuring safe food for all, however all actors in the food chain are responsible to ensure only safe food reaches the consumer, thus preventing foodborne illnesses. This is achieved through the implementation of strict hygiene rules and a public veterinary and phytosanitary service that monitors animal products throughout the food chain, from farming to delivery in shops and restaurants. This regulation includes:
Freeman also narrated The True Story of Glory Continues, a documentary about the 54th Massachusetts Infantry Regiment. In 1992, he appeared in Clint Eastwood's western Unforgiven, which won four Academy Awards including Best Picture. The film depicts William Munny (Eastwood), an aging outlaw and killer who takes on one more job with old friend Ned Logan (Freeman). Unforgiven was widely acclaimed, with one critic calling Freeman's performance "outstanding". Also in 1992 Freeman starred in the John G. Avildsen directed drama The Power of One acting opposite Stephen Dorf and John Gielgud in a loose adaptation of Bryce Courtenay's 1989 novel of the same name, in which he plays boxing coach Geel Piet. In 1993, Freeman made his directorial debut with the drama Bopha!, which tells the story of a black policeman (Danny Glover) during South Africa's apartheid era. Bopha! was well-received, in particular for Freeman's directing. Hal Hinson of The Washington Post wrote: "Freeman lays out the father-son dynamics with great skill and very little fuss. There's no hysteria in his approach; instead, he sticks to the facts, relying on his cast to provide the emotion. The result is a surprisingly powerful, insightful film." Kenneth Turan from Los Angeles Times also complimented Freeman's direction but thought the film was "more predictable than powerful". In 1994, Freeman portrayed Red, the redeemed convict in Frank Darabont's acclaimed drama The Shawshank Redemption, with co-star Tim Robbins. It is based on the 1982 Stephen King novella Rita Hayworth and the Shawshank Redemption.
==== TP0624 ==== Outer Membrane Protein A (OmpA) domain-containing proteins are necessary for maintaining structural integrity in gram-negative bacteria. These domains contain peptidoglycan binding sites which creates a "structural bridge between the peptidoglycan layer and the outer memebrane." The protein TP0624 found in T. pallidum has been proposed to facilitate this structural link, as well as interactions between outer membrane proteins and corresponding domains on the thin peptidoglycan layer.
== Calculation == Molecular masses are calculated from the atomic masses of each nuclide present in the molecule, while molar masses and relative molecular masses (molecular weights) are calculated from the standard atomic weights of each element. The standard atomic weight takes into account the isotopic distribution of the element in a given sample (usually assumed to be "normal"). For example, water has a molar mass of 18.0153(3) g/mol, but individual water molecules have molecular masses between 18.010 564 6863(15) Da (1H216O) and 22.027 7364(9) Da (2H218O). Atomic and molecular masses are usually reported in daltons, which is defined in terms of the mass of the isotope 12C (carbon-12). However, the name unified atomic mass unit (u) is still used in common practice. Relative atomic and molecular masses as defined are dimensionless. Molar masses when expressed in g/mol have almost identical numerical values as relative atomic and molecular masses. For example, the molar mass and molecular mass of methane, whose molecular formula is CH4, are calculated respectively as follows:
Sources: en.wikipedia.org
Adsorption refrigeration also uses a thermally driven sorption process, but the refrigerant is taken up by a solid adsorbent rather than dissolved in a liquid absorbent. Common adsorption working pairs include water with silica gel or zeolite, and methanol with activated carbon. In a basic adsorption cycle, heating the adsorbent releases refrigerant vapour, which is condensed. When the adsorbent is subsequently cooled, it adsorbs refrigerant vapour again; evaporation of the refrigerant during this part of the cycle produces the cooling effect. Adsorption systems can be driven by low-grade heat sources, including solar or waste heat. Adsorption refrigeration has been extensively studied as an alternative to conventional vapor-compression cooling. Reviews have noted advantages such as the potential use of low-grade thermal energy and relatively simple solid-sorbent systems, while also identifying limitations including comparatively low performance and continuing technical and economic challenges. The main difference from absorption cycle is that in adsorption cycle, the refrigerant (adsorbate) can be ammonia, water, methanol, etc., while the adsorbent is a solid, such as silica gel, activated carbon, or zeolite, while in the absorption cycle the absorbent is liquid. The reason adsorption refrigeration technology has been extensively researched in recent 30 years lies in that the operation of an adsorption refrigeration system is often noiseless, non-corrosive and environmentally friendly.
Following extended discussions with Richwood Pharmaceuticals regarding the resolution of a large number of issues related to the company's numerous violations of FDA regulations, the FDA formally approved the first Obetrol labeling/sNDA revisions in 1996, including a name change to Adderall and a restoration of its status as an approved drug product. In 1997 Richwood Pharmaceuticals was acquired by Shire Pharmaceuticals in a $186 million transaction. Richwood Pharmaceuticals, which later merged with Shire, introduced the Adderall brand in 1996 as an instant-release tablet. In 2006, Shire agreed to sell rights to the Adderall name for the instant-release form of the medication to Duramed Pharmaceuticals. DuraMed Pharmaceuticals was acquired by Teva Pharmaceuticals in 2008 during their acquisition of Barr Pharmaceuticals, including Barr's Duramed division. The first generic version of Adderall IR was introduced to the market in 2002. Later on, Barr and Shire reached a settlement agreement permitting Barr to offer a generic form of the extended-release drug beginning in April 2009.
=== Oceania === The white shark population is estimated to be 2,500–6,750 individuals around eastern Australia and New Zealand. In 1999, the Australian Government gave legal protection to the species under the Environmental Protection and Biodiversity Conservation (EPBC) Act, subsequently declaring it vulnerable in 2000. Similar protections exist at the state level—some predating federal law—with New South Wales, Tasmania, and Western Australia listing the species as vulnerable, and Victoria classifying it as endangered. To bolster these protections, the federal government launched the White Shark Recovery Plan in 2002 to mandate conservation research and regulate shark-related trade and tourism. An updated 2013 recovery plan reported moderate success, with 14 of its 34 original objectives completed. A study in 2012 found that Australia's white shark population is separated by the Bass Strait into genetically distinct eastern and western populations, necessitating regionalized conservation strategies. Population declines prior to protection were driven by commercial and sport fishing, along with entanglement in beach protection netting. By 2013, incidental deaths from commercial and recreational fishing had decreased, yet the population had not fully recovered. Despite federal protections, white sharks are still killed in state-run "shark control" programs (shark culling) intended to reduce attacks. Queensland and New South Wales continue to use nets and traps, which contribute to declining numbers in eastern Australia.
== Treatment == Treatment is normally azithromycin by oral tablets, or less commonly by a course of other antibiotics, such as benzathine benzylpenicillin, an alternative for patients where azithromycin treatment failed, or tetracycline tablets. Penicillin has been the front-line treatment since at least the 1960s, but there is no solid evidence of the evolution of penicillin resistance in yaws. The historical strategy for the eradication of yaws (1952–1964) was:
==== Historic safety concerns ==== In 1952, Kuroya and his colleagues attempted to identify an infectious agent in human tissue samples at Tohoku University Hospital, Sendai, Japan. The samples were taken from the lung of a newborn child that was affected by fatal pneumonia. The primary isolate from the samples was passaged in mice and subsequently in embryonated eggs. The isolated infectious agent was later called Sendai virus, which was used interchangeably with the name "hemagglutinating virus of Japan". Kuroya and his colleagues were convinced that they isolated the virus, which is a new etiological agent for human respiratory infections. Later in 1954, Fukumi and his colleagues at the Japan National Institute of Health put forward an alternative explanation for the origin of the virus. It was suggested that the mice used to passage the virus were infected with the mouse virus. Thus, mouse virus was later transferred to embryonated eggs, isolated and finally named the Sendai virus. This explanation of Fukumi, pointing to the mouse rather than the human origin of the virus, has been supported by numerous scientific data later. The historical aspects of the Sendai virus isolation and controversy behind it are well described in the review. Thus, for some time, it was erroneously assumed that Sendai virus is human disease causing pathogen. The incorrect assumption that the virus was isolated from human infectious material is still reported by Encyclopædia Britannica and by ATCC in the description of the history of the viral isolate Sendai/52.
Sources: en.wikipedia.org
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.
The compound is registered as a medicine in Russia, so clinical work has concentrated there. Trials elsewhere are few and generally small. This geographic concentration is a recognized limitation in evidence reviews.
Some fraction may reach the central nervous system through olfactory pathways, and this is often cited as the rationale for the nasal route. The size of that fraction in humans is not well quantified. Blood concentrations after nasal dosing are low, which complicates measurement.
Each freeze-thaw cycle can degrade a fraction of the peptide and promote aggregation. Dividing a stock solution into single-use volumes removes repeated cycling as a variable. It also limits the time a thawed solution spends at room temperature.