If you have been reading about Lyophilisation and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-01-25. Numbers and descriptions here follow the published literature rather than marketing material.
Proposed mechanisms centre on the GABAergic system. Animal and tissue studies report changes in GABA-A receptor expression and reduced activity of GABA transaminase, the enzyme that degrades GABA. Effects on monoamine turnover, including serotonin and dopamine pathways, are also described, and a separate line of work links the peptide to increased expression of brain-derived neurotrophic factor in hippocampal tissue. Most of these findings come from rodent models and cell preparations. How the individual observations combine into a single coherent mode of action is not settled.
Pharmacokinetic data are sparse and largely derived from animal work. After intranasal administration the peptide appears in plasma within minutes, and reported half-lives are short, on the order of minutes to tens of minutes. Degradation proceeds through ordinary proteolytic cleavage into constituent amino acids and smaller fragments. Direct evidence that intact Selank reaches brain tissue in meaningful amounts is limited, and the extent of blood-brain barrier penetration is debated. Some authors argue that fragments, not the parent peptide, carry much of the observed activity.
Published clinical work is concentrated in Russian-language journals and generally involves small samples without independent replication. Systematic reviews in English note the shortage of randomised, placebo-controlled trials and the difficulty of verifying methods from translated reports. Outcome measures vary between studies, which complicates pooling of results. Interest in the compound as a cognitive or anxiolytic agent therefore rests on a thinner evidence base than the volume of citations suggests. Replication in well-powered trials with preregistered endpoints would be needed before firm conclusions about efficacy can be drawn.
Published work on this peptide almost always uses intranasal delivery, with drops or a spray applied to the nasal mucosa. Some animal experiments have used subcutaneous or intraperitoneal injection, and a smaller number have compared routes directly. Oral administration is not a focus of the literature, because short peptides of this size are broken down by digestive enzymes and cross intestinal barriers poorly. How much of an intranasal dose reaches the bloodstream intact in humans remains an open question.
Animal studies have examined behaviour in tests of anxiety, memory retention and stress response, and several report changes in neurotrophic or neurotransmitter-related markers. The human evidence base is much smaller, consisting mainly of short trials conducted in Russia with limited reporting in English-language journals. Sample sizes are modest and outcome measures vary between studies, so the findings are best described as preliminary. Independent replication under modern trial standards has not been widely reported.
Outside its country of origin the compound is generally handled as a research chemical rather than an approved medicine. No regulatory approval from the United States Food and Drug Administration or the European Medicines Agency has been granted for human use. Identity and purity are normally checked by reverse-phase high-performance liquid chromatography, with mass spectrometry used to confirm the molecular mass. Lyophilised material is stored cold and desiccated, and repeated freeze-thaw cycles are avoided.
| Property | Value | Notes |
|---|---|---|
| Primary route studied | Intranasal | Also examined parenterally in animal work |
| Reported plasma half-life | Minutes to tens of minutes | Values vary widely between reports |
| Main model systems | Rodent behavioural and cell assays | Human trials are few and small |
| Principal proposed targets | GABA-A receptor, GABA transaminase | Monoamine and neurotrophic pathways also reported |
| Evidence grade | Preliminary | Limited independent replication |
The compound has a calculated molecular weight near 751.9 daltons and carries a net positive charge at physiological pH because of its arginine residue. It dissolves freely in water and in common aqueous buffers, and typically appears as a white or off-white lyophilized powder. The amide backbone makes the molecule susceptible to peptidases, which limits oral use and favors intranasal or parenteral routes. Nomenclature in the literature varies: the substance is also described by the sequence abbreviation TP-7 and by a Russian trade designation.
Regulatory status differs sharply by region. Selank holds a Russian marketing authorization, where it is supplied mainly as nasal drops, while authorities elsewhere have not approved it for medical use. Material sold internationally is therefore usually labeled as a research chemical rather than a medicine. Peer-reviewed publications come predominantly from Russian laboratories, and sample sizes are generally small. Whether the compound produces comparable effects under independent, well-controlled replication remains an open question that the broader literature has not settled.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, with mass spectrometry used to confirm molecular mass and sequence information. Amino acid analysis and peptide mapping may supplement these methods. Certified reference standards are scarce, and many commercial lots are sold as research chemicals without a pharmacopoeial monograph. Regulatory treatment differs by country: Selank is a registered prescription medicine in Russia, while in the European Union and the United States it is not an approved drug and may fall under research-chemical or unapproved-product frameworks.
Selank is a hydrophilic peptide and dissolves readily in water and in aqueous buffers. The lyophilised powder is typically a white to off-white solid. Because short peptides are prone to hydrolysis and oxidation, handling benefits from limiting exposure to heat, moisture and strong light. Working solutions are commonly prepared in sterile water or saline, and repeated freeze-thaw cycles are avoided to reduce aggregation and loss of activity. These practices reflect general laboratory convention rather than published stability specifications.
Dry powder is normally held at -20 degrees Celsius or lower, in a sealed container with desiccant and protection from light. Reconstituted solutions are usually kept at 2 to 8 degrees Celsius for short periods and frozen for longer ones. Proline residues at several positions are generally associated with some resistance to peptidase attack, but chemical stability still declines at neutral to alkaline pH and at elevated temperature. Exact shelf-life figures are product-specific and are not standardised across suppliers.
The unifying mechanism of bioactivity in all enediyne antibiotics is the Bergman cyclization, wherein the enediyne portion undergoes spontaneous cycloaromatization to generate a para-benzyne biradical activated toward homolytic abstraction of hydrogen from suitable donors, including the deoxyribose sugars of DNA. This generates a carbon-centered free radical on DNA, which undergoes oxidation by molecular oxygen. The resulting peroxide decomposes to form single- or double-stranded breaks in DNA, ultimately leading to cell death. With considerable sequence selectivity, kedarcidin chromophore binds and cleaves DNA preferentially at TCCTn-mer sites, producing single-strand breaks. Puzzlingly, while the structure of kedarcidin chromophore is most closely related to that of neocarzinostatin chromophore, the former shares sequence-specificity with the structurally distinct calicheamicin enediyne antitumor antibiotic. The naphthoic acid substructure has been implicated in DNA binding, likely through intercalation. To this end, kedarcidin chromophore–induced DNA cleavage is diminished by the addition of divalent cations such as Ca2+ and Mg2+, which chelatively bind the naphthoic acid group of kedarcidin chromophore and thus lessen its affinity for DNA. Competition experiments with netropsin, a known binder of the DNA minor groove, indicate that kedarcidin likely binds the minor groove as well.
== Life and education == Born in Chattanooga, Tennessee (April 5, 1970), Sherrill received his S.B. in chemistry from MIT. He received his Ph.D. in 1996 from the University of Georgia, working with Professor Henry F. Schefer, III on highly correlated configuration interaction methods. He was an NSF Postdoctoral Fellow in the laboratory of Martin Head-Gordon at the University of California, Berkeley.
== Medical use == Pirbuterol is used in asthma for reversal of acute bronchospasm, and also as a maintenance medication to prevent future attacks. It should be used in patients 12 years of age and older with or without concurrent theophylline and/or inhaled corticosteroid.
Sources: en.wikipedia.org
Neuroleptic malignant syndrome (NMS) and catatonia are both life-threatening conditions that share many of the same characteristics including fever, autonomic instability, rigidity, and delirium. Lab values of low serum iron, elevated creatine kinase, and white blood cell count are also shared by the two disorders, further complicating the diagnosis. There are features of malignant catatonia (posturing, impulsivity, etc.) that are absent from NMS and the lab results are not as consistent in malignant catatonia as they are in NMS. Some experts consider NMS to be a drug-induced condition associated with antipsychotics, particularly first generation antipsychotics, but it has not been established as a subtype. Therefore, discontinuing antipsychotics and starting benzodiazepines is a treatment for this condition, and similarly it is helpful in catatonia as well. (See table 2 above). Anti-NMDA receptor encephalitis is an autoimmune disorder characterized by neuropsychiatric features and the presence of IgG antibodies. The presentation of anti-NMDA encephalitis has been categorized into 5 phases: Prodromal phase Psychotic phase Unresponsive phase Hyperkinetic phase Recovery phase The psychotic phase progresses into the unresponsive phase characterized by mutism, decreased motor activity, and catatonia.
== Deliberate targeting == A 2026 United Nations report found reasonable grounds to conclude that Palestinian children had been deliberately targeted by Israeli security forces during the conflict. The report documented cases of children being killed by single, precise gunshots by snipers and drones, frequently in the head or upper torso, suggesting a deliberate intention to target them rather than incidental harm. Doctors who had undertaken medical missions in Gaza told the Commission that it appeared Israeli Defense Force (IDF) were engaging in a "game of target practice", with different parts of children's bodies reportedly being targeted on different days. The report also documented systematic attacks on child-essential infrastructure that had contributed to preventable child deaths and long-term disabilities. The Commission further examined dehumanising rhetoric by political leaders, soldiers and public figures, which it said contributed to an environment in which violence against Palestinian children was more readily accepted.
Arsenic trioxide exerts its toxicity primarily through the induction of oxidative stress, disruption of cellular energy production, and interference with key protein functions. One major mechanism involves the generation of reactive oxygen species (ROS), leading to oxidative modifications of cellular biomolecules, organelle damage, and ultimately cell death. Arsenic trioxide also inhibits critical cellular enzymes such as pyruvate dehydrogenase, thereby disrupting mitochondrial ATP production and cellular respiration, which results in energy failure and can trigger both necrotic and apoptotic cell death. Furthermore, it can interfere with DNA repair processes by inhibiting enzymes involved in base and nucleotide excision repair and by interacting with protein structures such as zinc fingers in repair proteins. In cardiac tissues, arsenic trioxide disrupts ion channel function, notably by blocking the hERG potassium channel and altering calcium channel activity, which can lead to prolonged QT intervals and arrhythmias, sometimes causing fatal cardiac events. The broad range of affected signaling and metabolic pathways helps explain the widespread multi-organ toxicity associated with arsenic trioxide exposure.
Subsequent clinical studies have supported the effectiveness and stability of CAIRS across various forms of corneal ectasia, with promising results maintained for up to five years. Dr Jacob also holds patents for specialised trephination and implantation instruments, further standardising and refining the procedure. The high degree of customisation available with CAIRS keratoplasty is one of its greatest clinical advantages, enabling surgeons to tailor treatment to the patient's specific topography and visual needs. Some commercial providers have introduced branded versions of pre-prepared donor segments, such as "CTAK". While the branding differs, these procedures are still CAIRS keratoplasty; the trademarked names apply only to the tissue supply or preparation system rather than the surgical concept itself. To support surgeons in planning CAIRS procedures, Dr Brendan Cronin and Dr David Gunn, keratoconus specialists based in Brisbane, Australia, have developed a free web-based planning resource: www.cairsplan.com. This platform provides guidance and planning tools to help optimize surgical outcomes and expand access to this innovative approach.
Sources: en.wikipedia.org
Reports describe modulation of GABA signalling, changes in monoamine turnover and effects on neurotrophic factor expression. These observations come mainly from animal and cell studies. A single unifying mechanism has not been demonstrated.
The peptide enters plasma rapidly and is broken down by ordinary proteases into amino acids and shorter fragments. Reported half-lives are short. Whether meaningful amounts of the intact molecule reach the brain is an open question.
Most clinical reports are small, published in Russian and not independently replicated. English-language reviews highlight the absence of large randomised trials. Conclusions about efficacy should be treated as provisional.
Most published work uses intranasal application, either as drops or as a nasal spray. Injection routes appear in a smaller set of animal experiments. Oral use is uncommon in the literature because peptide breakdown and poor absorption limit this route.