The short version of lyophilized powder fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Identity and purity of semax are established with reversed-phase high-performance liquid chromatography coupled to ultraviolet detection, usually at 214 nanometres. Mass spectrometry, most often electrospray ionisation in positive mode, confirms the molecular mass and reveals truncated sequences. Amino acid analysis and peptide mapping after enzymatic digestion provide additional structural confirmation. Laboratories typically report purity as the percentage area of the main peak, a figure that does not capture isomeric or oxidised variants unless the method resolves them.
The peptide is prone to several degradation pathways. Oxidation of the methionine residue produces a sulfoxide that elutes close to the parent peak in many chromatographic systems. Hydrolysis of peptide bonds and deamidation of susceptible residues in related sequences also reduce purity over time. Lyophilised material kept dry at minus twenty degrees Celsius and shielded from light is the most stable form commonly described in laboratory practice.
Material sold for laboratory use varies widely in stated purity and documentation. A certificate of analysis should list the analytical method, the column and detector used, and the observed purity value. Independent verification by an outside laboratory is the practical way to confirm identity when documentation is absent or internally inconsistent. Regulatory status differs by country, and a product legal in one jurisdiction may be unapproved or controlled in another.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility class | Freely soluble in water | Also dissolves in aqueous buffers |
| Typical storage temperature | -20 °C | Dry, desiccated, protected from light |
| Typical analytical method | RP-HPLC with UV detection | Often paired with LC-MS |
| Water content | Reported as Karl Fischer value | Freeze-dried material is hygroscopic |
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。
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。
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
Quality documentation for research-grade peptide usually includes a certificate of analysis stating purity, identity, and residual counterion content. Batch-to-batch variation in purity and salt form is a recognized issue, and comparisons across suppliers require attention to the exact counterion, for example acetate versus trifluoroacetate. Sequence verification by tandem mass spectrometry provides stronger evidence than a single mass measurement. For any study reporting biological results, the analytical method and the measured purity should be stated explicitly. Independent verification of supplier claims is considered good practice.
== Medical uses == Ciclosporin is indicated to treat and prevent graft-versus-host disease in bone marrow transplantation and to prevent rejection of kidney, heart, and liver transplants. It is also approved in the US for treating of rheumatoid arthritis and psoriasis, persistent nummular keratitis following adenoviral keratoconjunctivitis, and as eye drops for treating dry eyes caused by Sjögren's disease and meibomian gland dysfunction. In addition to these indications, ciclosporin is also used in severe atopic dermatitis, It has been used in severe rheumatoid arthritis and related diseases. Ciclosporin has also been used in people with acute severe ulcerative colitis and hives that do not respond to treatment with steroids.
diphtheriae infection (Barcoo rot, diphtheric desert sore, septic sore, Veldt sore) Cutaneous group B streptococcal infection Cutaneous Pasteurella hemolytica infection Cutaneous Streptococcus iniae infection Dermatitis gangrenosa (gangrene of the skin) Ecthyma Ecthyma gangrenosum Ehrlichiosis ewingii infection Elephantiasis nostras Endemic typhus (murine typhus) Epidemic typhus (epidemic louse-borne typhus) Erysipelas (ignis sacer, Saint Anthony's fire) Erysipeloid of Rosenbach Erythema marginatum Erythrasma External otitis (otitis externa, swimmer's ear) Felon Flea-borne spotted fever Flinders Island spotted fever Flying squirrel typhus Folliculitis Fournier gangrene (Fournier gangrene of the penis or scrotum) Furunculosis (boil) Gas gangrene (clostridial myonecrosis, myonecrosis) Glanders (equinia, farcy, malleus) Gonococcemia (arthritis–dermatosis syndrome, disseminated gonococcal infection) Gonorrhea (clap) Gram-negative folliculitis Gram-negative toe web infection Granuloma inguinale (Donovanosis, granuloma genitoinguinale, granuloma inguinale tropicum, granuloma venereum, granuloma venereum genitoinguinale, lupoid form of groin ulceration, serpiginous ulceration of the groin, ulcerating granuloma of the pudendum, ulcerating sclerosing granuloma) Green nail syndrome Group JK Corynebacterium sepsis Haemophilus influenzae cellulitis Helicobacter cellulitis Hospital furunculosis Hot tub folliculitis (Pseudomonas aeruginosa folliculitis) Human granulocytotropic anaplasmosis Human monocytotropic ehrlichiosis Impetigo contagiosa Japanese spotted fever Leptospirosis (Fort Bragg fever, pretibial fever, Weil's disease) Listeriosis Ludwig's angina Lupoid sycosis Lyme disease (Afzelius' disease, Lyme borreliosis) Lymphogranuloma venereum (climatic bubo, Durand–Nicolas–Favre disease, lymphogranuloma inguinale, poradenitis inguinale, strumous bubo) Malakoplakia (malacoplakia) Mediterranean spotted fever (Boutonneuse fever) Melioidosis (Whitmore's disease) Meningococcemia Missouri Lyme disease Mycoplasma infection Necrotizing fasciitis (flesh-eating bacteria syndrome) Neonatal toxic shock-like exanthematous disease Nocardiosis Noma neonatorum North Asian tick typhus Ophthalmia neonatorum Oroya fever (Carrion's disease) Pasteurellosis Perianal cellulitis (perineal dermatitis, streptococcal perianal disease) Periapical abscess Pinta Pitted keratolysis (keratolysis plantare sulcatum, keratoma plantare sulcatum, ringed keratolysis) Plague Primary gonococcal dermatitis Pseudomonal pyoderma Pseudomonas hot-foot syndrome Pyogenic paronychia Pyomyositis Q fever Queensland tick typhus Rat-bite fever Recurrent toxin-mediated perineal erythema Rhinoscleroma Rickettsia aeschlimannii infection Rickettsialpox Rocky Mountain spotted fever Saber shin (anterior tibial bowing) Saddle nose Salmonellosis Scarlet fever Scrub typhus (Tsutsugamushi fever) Shigellosis Staphylococcal scalded skin syndrome (pemphigus neonatorum, Ritter's disease) Streptococcal intertrigo Superficial pustular folliculitis (impetigo of Bockhart, superficial folliculitis) Sycosis vulgaris (barber's itch, sycosis barbae) Syphilid Syphilis (lues) Tick-borne lymphadenopathy Toxic shock syndrome (streptococcal toxic shock syndrome, streptococcal toxic shock-like syndrome, toxic streptococcal syndrome) Trench fever (five-day fever, quintan fever, urban trench fever) Tropical ulcer (Aden ulcer, jungle rot, Malabar ulcer, tropical phagedena) Tularemia (deer fly fever, Ohara's disease, Pahvant Valley plague, rabbit fever) Verruga peruana Vibrio vulnificus infection Yaws (bouba, frambösie, parangi, pian)
== History == The prothrombin time was developed by Armand J. Quick and colleagues in 1935, and a second method was published by Paul Owren, also called the "p and p" or "prothrombin and proconvertin" method. It aided in the identification of the anticoagulants dicumarol and warfarin, and was used subsequently as a measure of activity for warfarin when used therapeutically. The INR was invented in the early 1980s by Tom Kirkwood working at the UK National Institute for Biological Standards and Control (and subsequently at the UK National Institute for Medical Research) to provide a consistent way of expressing the prothrombin time ratio, which had previously suffered from a large degree of variation between centres using different reagents. The INR was coupled to Dr Kirkwood's simultaneous invention of the International Sensitivity Index (ISI), which provided the means to calibrate different batches of thromboplastins to an international standard. The INR became widely accepted worldwide, especially after endorsement by the World Health Organization.
Sources: en.wikipedia.org
== Prognosis == With treatment, the majority of people with BPD can find relief from distressing symptoms and achieve remission, defined as a consistent relief from symptoms for at least two years. Remission rates are about 50–70% over five years. The remission rate is estimated to be around 50% at ten years, with 93% of people being able to achieve a two-year remission and 86% achieving at least a four-year remission, with a 30% risk of relapse over 10 years. Patient personality can play an important role during the therapeutic process, leading to better clinical outcomes. Recent research has shown that BPD patients undergoing dialectical behavior therapy (DBT) exhibit better clinical outcomes correlated with higher levels of the trait of agreeableness in the patient, compared to patients either low in agreeableness or not being treated with DBT. This association was mediated through the strength of a working alliance between patient and therapist; that is, more agreeable patients developed stronger working alliances with their therapists, which, in turn, led to better clinical outcomes. In addition to recovering from distressing symptoms, people with BPD can also achieve high levels of psychosocial functioning. A longitudinal study tracking the social and work abilities of participants with BPD found that six years after diagnosis, 56% of participants had good function in work and social environments, compared to 26% of participants when they were first diagnosed. Vocational achievement was generally more limited, even compared to those with other personality disorders.
PET scanning with the radiotracer [18F]fluorodeoxyglucose (FDG) is widely used in clinical oncology. FDG is a glucose analog that is taken up by glucose-using cells and phosphorylated by hexokinase (whose mitochondrial form is significantly elevated in cancer). Metabolic trapping of the radioactive glucose molecule allows the PET scan to be utilized. The concentrations of imaged FDG tracer indicate tissue metabolic activity as it corresponds to the regional glucose uptake. FDG is used to explore the possibility of cancer spreading to other body sites (cancer metastasis). These FDG PET scans for detecting cancer metastasis are the most common in standard medical care (representing 90% of current scans). The same tracer may also be used for the diagnosis of types of dementia. Less often, other radioactive tracers, usually but not always labelled with fluorine-18 (18F), are used to image the tissue concentration of different kinds of molecules of interest inside the body. Because the hydroxy group that is replaced by fluorine-18 to generate FDG is required for the next step in glucose metabolism in all cells, no further reactions occur in FDG. Furthermore, most tissues (with the notable exception of liver and kidneys) cannot remove the phosphate added by hexokinase. This means that FDG will remain trapped in any cell that takes it up until it decays, since phosphorylated sugars, due to their ionic charge, cannot exit from the cell.
A bronchoscopic transbronchial cryobiopsy, in which a camera is introduced into the airways followed by rapid freezing of an area of lung tissue prior to biopsy is associated with a lower complication rate and a much lower mortality rate compared to VATS or surgical biopsy with near comparable diagnostic accuracy. There are four types of histopathologic patterns seen in ILD: usual interstitial pneumonia, non-specific interstitial pneumonia, organizing pneumonia, and diffuse alveolar damage. There is significant overlap of the histopathological and radiologic features of each ILD type making diagnosis challenging; even with lung biopsy, 15% of cases of ILD cannot be classified.
== Society and culture == Prescriptions in the US for all sleeping pills (including zolpidem) steadily declined from around 57 million tablets in 2013, to around 47 million in 2017, possibly due to concern about prescribing addictive drugs amid the opioid crisis.
Sources: en.wikipedia.org
Reversed-phase high-performance liquid chromatography is the standard method, with detection in the ultraviolet range. Peak area percentage yields a purity figure for the main component. Mass spectrometry is normally run alongside to confirm molecular identity.
Dry lyophilised powder is generally kept at minus twenty degrees Celsius, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they encourage aggregation and moisture uptake. Solutions are less stable than the solid form and degrade faster at room temperature.
A certificate documents what the supplier measured, not what an independent party confirmed. Methods, instruments and acceptance criteria can differ between suppliers. Third-party testing is the usual way to resolve discrepancies.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.