A practical reference on intranasal delivery: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-02. Anything still debated is marked as such rather than presented as settled.
Clinical evidence comes mainly from small studies conducted in Russia, several of which were open-label or lacked robust blinding. Reported outcomes include lower anxiety scores, changes in attention measures, and effects on asthenic states following illness. Sample sizes are typically in the tens of participants, and independent replication outside the region is scarce. Reviews published in English generally note the limited methodological quality of the underlying trials. Whether the compound produces clinically meaningful effects under rigorous conditions remains unresolved.
Proposed mechanisms center on modulation of the GABA system, but no single molecular target has been confirmed. Rodent studies report changes in GABA-A receptor expression and in the turnover of serotonin, dopamine, and norepinephrine in several brain regions. Increases in brain-derived neurotrophic factor and its receptor have also been described after repeated administration. These findings come largely from animal models, and the degree to which they describe human neurochemistry remains an open question. The mechanism is best characterized as multi-system and not fully resolved.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Reported pharmacological effects center on reduced anxiety-like behavior in animal models and on measures of memory and learning. Proposed contributing mechanisms include modulation of GABAergic signaling, shifts in monoamine turnover, and changes in the activity of enzymes that degrade neuropeptides. Effects on the expression of genes linked to neuroplasticity have also been described. No single molecular target is widely accepted, and whether the behavioral findings arise from one pathway or several remains an open question.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
| Property | Value | Notes |
|---|---|---|
| Route studied | Intranasal | Predominant route in published reports |
| Circulation stability | Short, minutes scale | Peptidases cleave it; the tail slows the process |
| Analytical method | RP-HPLC with mass spectrometry | Used for identity and purity assessment |
| Reported outcome domains | Anxiety and cognitive measures | Derived from small, mostly regional trials |
| Regulatory status | Marketed in Russia | Availability outside that market is limited |
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.
Peptide stability depends strongly on temperature, moisture, and pH. Lyophilized Selank is generally most stable when stored cold and dry, with freezer temperatures commonly used for long-term storage. In solution, the compound is susceptible to hydrolysis and to microbial growth if it is not handled aseptically. The C-terminal proline-rich extension appears to slow enzymatic cleavage relative to tuftsin, though quantitative degradation rates vary with the matrix and the conditions tested. Published stability data specific to Selank remain sparse.
Quality assessment of Selank samples typically combines purity determination with identity confirmation and counter-ion analysis. Purity is usually reported as a percentage by chromatographic area, with values above 95 percent often quoted for research-grade material. Water content and residual solvents are checked in lyophilized batches because they affect both stability and accurate mass determination. A reported purity figure does not by itself establish that a sample is the intended sequence, so orthogonal methods are needed to rule out sequence isomers or truncation products.
Characterization of Selank in laboratory settings relies on standard peptide analytical techniques. Reverse-phase high-performance liquid chromatography separates the peptide from related impurities and degradation products, while mass spectrometry confirms molecular identity through accurate mass measurement. Amino acid analysis and peptide sequencing verify the primary structure when reference material is unavailable. Because Selank is a short chain, fragmentation-based analysis produces a diagnostic ion pattern that supports confident identification.
Lyophilised material kept dry at minus 20 degrees Celsius or colder is the most stable form, and suppliers commonly state a shelf life of two years or more under those conditions. Once dissolved, degradation accelerates through hydrolysis and deamidation, particularly at alkaline pH or elevated temperature. Working solutions are usually divided into single-use aliquots to avoid repeated freeze-thaw cycles. The choice of reconstitution solvent affects both stability and the ionic strength of the final preparation.
Reverse-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres is the standard purity method. Mass spectrometry, typically electrospray ionisation, confirms identity through the expected mass-to-charge pattern. Amino acid analysis can verify composition independently. Chiral purity requires separate techniques such as derivatisation followed by chromatographic separation, and such data are rarely reported for research-grade material.
Quantification in biological matrices relies on liquid chromatography coupled to tandem mass spectrometry with stable-isotope internal standards. Low plasma concentrations and adsorption to container surfaces both complicate measurement. Solid-phase extraction is often needed to reduce matrix interference before injection. Reported limits of quantification differ widely between laboratories, which makes direct comparison of pharmacokinetic results difficult and limits meta-analysis.
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== See also == Mepolizumab, anti–IL-5 to treat chronic rhinosinusitis with nasal polyps Omalizumab, anti–immunoglobulin E to treat chronic rhinosinusitis with nasal polyps Tezepelumab, anti-thymic stromal lymphopoietin to treat chronic rhinosinusitis with nasal polyps
== Gene == The ALDH2 gene is about 44 kbp in length and contains at least 13 exons which encode 517 amino acid residues. Except for the signal NH2-terminal peptide, which is absent in the mature enzyme, the amino acid sequence deduced from the exons coincided with the reported primary structure of human liver ALDH2. Several introns contain Alu repetitive sequences. A TATA-like sequence (TTATAAAA) and a CAAT-like sequence (GTCATCAT) are located 473 and 515 bp, respectively, upstream from the translation initiation codon.
== Competitions == The ARL controls the National Rugby League and NRL Women's Premiership as well as annual representative competitions such as the State of Origin series, the Indigenous All Stars Match, the Affiliated States Championship and the Women's National Championships. The ARL previously ran the National Youth Competition. This competition, which was for male players Under 20 years of age, was replaced in 2018 by state-run competitions. The New South Wales Rugby League run the Jersey Flegg Cup for male Under 21 players. The Queensland Rugby League run the Mal Meninga Cup for male Under 18 players, with players Under 21 that are outside NRL squads playing for clubs in the open-age Queensland Cup.
Sources: en.wikipedia.org
=== Subtypes === There are several subtypes of catatonia recognized: stuporous catatonia, excited catatonia, malignant catatonia, and periodic catatonia. Subtypes are defined by the group of symptoms and associated features that a person is experiencing or displaying. Although catatonia can be divided into subtypes, its presentation is often dynamic, and the same individual may exhibit different subtypes at different times. Stuporous catatonia is characterized by immobility, mutism, and a lack of response to the world around them. They may appear frozen in one position for long periods of time unable to eat, drink, or speak. Excited catatonia is characterized by odd mannerisms and gestures, purposeless or inappropriate actions, excessive motor activity, restlessness, stereotypy, impulsivity, agitation, and combativeness. Patients suffering from excited catatonia may have speech and actions that are repetitive or mimic another person's. This state is often characterized by hyperactivity, and the patient may have delusions and hallucinations. Malignant catatonia is characterized by fever, dramatic and rapid changes in blood pressure, increased heart rate and respiratory rate, and excessive sweating. This condition is life-threatening, and the patient's laboratory tests may come back abnormal. Periodic catatonia is characterized by a person having recurrent episodes of catatonia. Individuals will experience multiple episodes over time, with no signs of catatonia between episodes.
==== Strengthen cooperation in various fields ==== Although there are certain differences over the Russian invasion of Ukraine, the United States and India have strengthened cooperation in defense, semiconductors, critical minerals, space, climate, education, healthcare and other fields during the Joe Biden presidency. Biden also called the ties with India is "one of the defining relationships of the 21st Century". Modi and Biden reiterated the call for concerted action against all groups identified by the United Nations as terrorist organisations, including Al-Qaeda, ISIS (Daesh), Lashkar-e-Tayyiba (LeT), Jaish-e-Mohammad (JeM) and Hizb-ul-Mujhahideen (HuM). Also mentioned the Afghan Taliban authorities and Pakistan should to stop terrorism. The joint statement declared that two countries have strong ties spanning "seas to stars".
=== Thermoregulation === Blood circulation transports heat throughout the body, and adjustments to this flow are an important part of thermoregulation. Increasing blood flow to the surface (e.g., during warm weather or strenuous exercise) causes warmer skin, resulting in faster heat loss. In contrast, when the external temperature is low, blood flow to the extremities and surface of the skin is reduced to prevent heat loss and is circulated to the important organs of the body, preferentially.
Sources: en.wikipedia.org
Class 1 – clean wound: a wound that is not infected and without signs of inflammation. This type of wound is typically closed. By definition, this type of wound excludes any wounds of the respiratory, genital, alimentary, or urinary tract. Class 2 – clean-contaminated wound: a wound with a low level of contamination. May involve entry into the respiratory, genital, alimentary, or urinary tract. Class 3 – contaminated wound: an open, accidental wound resulting from trauma outside of a sterile setting is automatically considered a contaminated wound. Additionally, any surgical wound where there is a major break in sterile technique or obvious contamination from the gastrointestinal tract is considered a contaminated wound. Class 4 – dirty/infected: a wound with evidence of an existing clinical infection. Class 4 wounds are usually found in old traumatic wounds which were not adequately treated and will show evidence of devitalized tissue or gross purulence.
== Sustainability & Digital transformation == KEZAD Group incorporates environmental, social, and governance (ESG) standards and digital initiatives into its zone operations and infrastructure. Programmes include carbon capture and circular economy measures, plastic recycling, water reuse and waste management. The group has developed 24 km of landscaped areas and green corridors. KEZAD Group and BEEAH have formed a joint venture to deliver integrated, eco-friendly waste management services to customers across the group’s economic cities and free zones. It also partnered with Masdar on a green hydrogen hub project aligned with the UAE’s National Hydrogen Strategy and has collaborated with Siemens to support Industry 4.0 adoption and deploy smart manufacturing systems.
==== Disadvantages of Microbubbles for Drug Delivery ==== Microbubbles do not extravasate easily due to their large size, and hence their effects are relegated to the vasculature. Nanodroplets, perfluorocarbon liquid droplets surrounded by a lipid shell that vaporize due to an ultrasound pulse, offer a small diameter to promote extravasation and afford an alternative to microbubbles. Microbubbles have short half-lives on the order of minutes in circulation, which limits the treatment time. Microbubbles are filtered by the liver and spleen, and any drug conjugation would then also potentially pose a toxicity threat to these organs, should the microbubbles not have already released their cargo. Drug conjugations to microbubbles are complicated for translation, and these formulations would be difficult to scale up for widespread use. There can be a small amount hemorrhage into brain tissue when microbubbles are used to disrupt the blood brain barrier, though this is thought to be reversible.
Initial assessment of back pain consists of a history and physical examination. Important characterizing features of back pain include location, duration, severity, history of prior back pain and possible trauma. Other important components of the patient history include age, physical trauma, prior history of cancer, fever, weight loss, urinary incontinence, progressive weakness or expanding sensory changes, which can indicate a medically urgent condition. Functional disability related to back pain can be quantified using validated questionnaires such as the Oswestry Disability Index (ODI).
Sources: en.wikipedia.org
Reports describe effects on GABA-A receptor expression, monoamine turnover, and neurotrophic factor levels. These are proposed mechanisms drawn mainly from animal models. No single molecular target has been established.
Intranasal delivery is the route described in most published work. It is used because the peptide is degraded quickly once it reaches circulation. Direct evidence of brain penetration in humans is lacking.
Most trials are small, regionally concentrated, and often lack rigorous blinding or placebo control. Independent replication is limited. Reviews in English generally rate the evidence as preliminary.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.