A practical reference on Intranasal delivery: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-27 and is reviewed periodically as new material appears.
Purity assessment relies mainly on reverse-phase high-performance liquid chromatography with ultraviolet detection. Because the peptide lacks a strong chromophore, detection often uses backbone absorbance near 214 nm. Identity is confirmed by mass spectrometry, typically electrospray ionization or matrix-assisted laser desorption, comparing the measured mass against the expected value. Amino acid analysis can verify composition after acid hydrolysis. Diastereomer content and residual counterions are reported less often, although both can influence biological assays.
Lyophilized material is generally stable for extended periods when kept dry at or below minus twenty degrees Celsius. Working solutions are less stable, and common practice is to aliquot and freeze them so that repeated freeze-thaw cycles are avoided. Aqueous solutions are sensitive to pH extremes and to microbial growth, so short-term storage at refrigerator temperature is typical. Oxidation and hydrolysis are the principal degradation routes. Reconstitution with sterile water or a mild buffer is standard, and solutions should be protected from light.
The compound was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences during the 1980s and 1990s. The stated design goal was to retain the immunomodulatory and central nervous system activity attributed to tuftsin while improving resistance to enzymatic breakdown. Adding a proline-rich tail to the short parent peptide was a deliberate strategy, because proline residues restrict the conformations available to many peptidases. The same laboratory produced Semax, an ACTH fragment analog, and both compounds were developed in parallel as short, enzymatically stabilized peptides intended for intranasal use.
Selank is not a naturally occurring peptide and has no known endogenous counterpart in human physiology. Russian-language sources frequently call it TP-7, while English-language sources use the name Selank almost exclusively. Database indexing is uneven, partly because early reports appeared in regional journals that are not widely cataloged. Some summaries describe the material as a tuftsin analog and others as a synthetic heptapeptide; the labels overlap rather than conflict. Citing the primary sequence resolves ambiguity more reliably than the research or trade name alone.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter notation. Its structure consists of the immunomodulatory tetrapeptide tuftsin, Thr-Lys-Pro-Arg, extended at the carboxyl terminus by a Pro-Gly-Pro segment. The molecular formula is commonly given as C33H57N11O9, corresponding to a monoisotopic mass near 751.4 Da and an average molecular mass near 751.9 Da. All seven residues are proteinogenic amino acids, and the molecule carries no modified side chains or non-natural linkages.
| Property | Value | Notes |
|---|---|---|
| Typical purity report | 95% or higher by HPLC | Area percentage at 214 nm |
| Identity confirmation | Mass spectrometry | Electrospray or MALDI |
| Powder storage | -20 C, desiccated | Protect from light |
| Solution storage | 2-8 C short term | Freeze aliquots for longer |
| Quality document | Certificate of analysis | States method and value |
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.
Pharmacokinetic data are limited. Like most short peptides, Selank is vulnerable to plasma and tissue peptidases, and its measured half-life in circulation is short, on a minutes scale. The Pro-Gly-Pro tail slows this degradation but does not eliminate it. Intranasal administration is the route described in most reports, with absorption through the nasal mucosa and a hypothesized path into the central nervous system that avoids the blood-brain barrier. Direct measurements of human brain exposure are unavailable, so distribution claims rest on inference from animal work.
Handling follows standard practice for research peptides. Material is weighed in a low-humidity environment because the powder absorbs atmospheric moisture. Purity is reported as the percentage area of the main peak in a chromatogram, with specifications commonly set at 95 percent or higher; values below that threshold indicate the presence of truncated or modified species. Residual trifluoroacetate from purification is often present and may affect mass balance. Certificates of analysis should state the analytical method, the column and gradient used, and the lot-specific retention time so that results can be compared across suppliers.
Identity and purity of selank are established with reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The peptide elutes from C18 columns with acetonitrile gradients in water containing trifluoroacetic acid or formic acid, and detection is usually performed by ultraviolet absorbance near 214 nm. Electrospray ionization in positive mode gives a doubly protonated ion near m/z 377, consistent with a mass of about 752 Da. Amino acid analysis or tandem mass spectrometry of fragment ions confirms the sequence. Because the molecule has no aromatic residues, it lacks a usable 280 nm chromophore, so low-wavelength detection or mass spectrometry is required.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Naming for this compound is not fully standardised in English sources. The spelling Selanc appears in some transliterations, and catalogue entries may instead list the peptide sequence itself as the identifier. Reference material sometimes groups it with other short synthetic peptides studied for behavioural effects, which can create confusion when citations are compared. Distinguishing the exact sequence from related tuftsin analogues is therefore a practical first step when reviewing any dataset or specification sheet.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
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.
=== Economics === Belimumab is primarily used in people with systemic lupus erythematosus. When it was introduced in 2011, it was the first new drug approved to treat lupus in 56 years. Sales rose to $31.2 million in the first quarter of 2012. The total cost for the first year of treatment with belimumab is $28,000. Belimumab is much more expensive than other drugs used to treat lupus, including prednisone ($140 per year), hydroxychloroquine ($132), oral methotrexate ($432), azathioprine ($468), and mycophenolate mofetil ($1,224). In the United Kingdom, the National Institute for Health and Care Excellence calculated the cost of belimumab at £61,200 per quality-adjusted life year (QALY). This is more than the normally accepted cost of £20,000 to £30,000 per QALY. The manufacturer offered the UK National Health Service a discount of a confidential amount, which still did not bring it into the acceptable range.
=== International === European Commission President Ursula von der Leyen welcomed the agreement and emphasized its importance in reducing violence and enabling humanitarian relief. The Indian Ministry of External Affairs also welcomed the initiative. Iran announced that passage of commercial vessels through the Strait of Hormuz is completely open during the truce in Lebanon. Iran later said that it closed the Strait of Hormuz again in response to the US refusing to lift its naval blockade.
Psychotherapy involves a formal relationship between professional and client—usually an individual, couple, family, or small group—that employs a set of procedures intended to form a therapeutic alliance, explore the nature of psychological problems, and encourage new ways of thinking, feeling, or behaving. Clinicians have a wide range of individual interventions to draw from, often guided by their training—for example, a cognitive behavioral therapy (CBT) clinician might use worksheets to record distressing cognitions, a psychoanalyst might encourage free association, while a psychologist trained in Gestalt techniques might focus on immediate interactions between client and therapist. Clinical psychologists generally seek to base their work on research evidence and outcome studies as well as on trained clinical judgment. Although there are literally dozens of recognized therapeutic orientations, their differences can often be categorized on two dimensions: insight vs. action and in-session vs. out-session.
== Function == Microproteins function as post-translational regulators. Microproteins disrupt the formation of heterodimeric, homodimeric, or multimeric complexes. Furthermore, microproteins can interact with any protein that requires functional dimers to function normally. The primary targets are transcription factors that bind to DNA as dimers. Microproteins regulate these complexes by creating homotypic dimers with the targets and inhibit protein complex function. The two types of miP inhibitions are: homotypic miP inhibition and heterotypic miP inhibition. In homotypic miP inhibition, microproteins interact with proteins with similar protein-protein interaction (PPI) domain. In heterotypic miP inhibition, microproteins interact with proteins with different but compatible PPI domain. In both types of inhibition, microproteins interfere and prevent the PPI domains from interacting with their normal proteins. Microproteins plays roles in biological process such as immunity and inflammation, cancer and cell cycle regulation, cellular transport, muscle and heart functions, gene expression and genome maintenance, proteostasis, and metabolic homeostasis.
Sources: en.wikipedia.org
Several scandals affected Uribe's administration; the Colombian parapolitics scandal expanded during his second term, involving numerous members of the administration's ruling coalition. Many pro-government lawmakers, such as the President's cousin Mario Uribe, were also investigated for their possible ties to paramilitary organizations. At the end of 2007, FARC agreed to release former senator Consuelo González, politician Clara Rojas, and her son Emmanuel, born in captivity after a relationship with one of her captors. Operation Emmanuel was proposed and set up by Venezuelan President Hugo Chávez, with the permission of the Colombian government. The mission was approved on December 26; however, on December 31, FARC claimed that the hostage release had been delayed because of Colombian military operations. At the same time, Colombian President Álvaro Uribe indicated that FARC had not freed the three hostages because Emmanuel may not be in their hands anymore. Two FARC gunmen were taken prisoner. Colombian authorities added that a boy matching Emmanuel's description had been taken to a hospital in San José del Guaviare in June 2005. The child was in poor condition; one of his arms was hurt, he had severe malnutrition, and he had diseases that are commonly suffered in the jungle. Having been evidently mistreated, the boy was later sent to a foster home in Bogotá, and DNA tests were announced to confirm his identity.
== Medical uses == Brimonidine is indicated for the lowering of intraocular pressure in people with open-angle glaucoma or ocular hypertension. It is also used to reduce redness of the eye. The gel is indicated for the topical treatment of persistent (nontransient) facial erythema of rosacea in adults 18 years of age or older. A 2017 Cochrane review found insufficient evidence to determine if brimonidine slows optic nerve damage.
Numerous events are hosted on the lawn at Bryant Park. Bryant Park Movie Nights, begun in the early 1990s, take place on Monday evenings during the summer. Various free musical performances are sponsored by corporations during months with warm weather, including Broadway in Bryant Park, sponsored by iHeartMedia and featuring performers from current Broadway musicals, integrated with content provided by event sponsors. The park has various activity areas open all day long, including board games, chess and backgammon, a putting green and Kubb area, an Art Cart, ping pong tables, and Petanque courts. The parks also offer free classes in juggling, yoga, tai chi, and knitting. In the 40th Street plaza of the park, there is a station called Bryant Park Games where visitors can borrow an array of games, including Chinese chess and quoits. In addition, chess and table tennis can also be played at Bryant Park. Food and drink are served at four park-operated concessionary kiosks. There are two additional kiosks on Fifth Avenue, bringing the total of concessionaires near Bryant Park to six.
The plasmon resonance displayed by nanoparticles, gold particles are most often used as an example, can be altered using the interfacial layer. When either anionic or cationic ligands bound to a nanoparticle made of gold for example are increased in length, the wavelength of the plasmon resonance will shift to red. An example of another effect, that has recently been observed by Amendola et al. on small gold nanoparticles, of 10 nm or less, is that dense monolayers that consist of certain specific short chain ligands tend to dampen the surface plasmon resonance effects. Plasmon resonance can be used to analyze the surfactants of the nanoparticle. This principle is based on the so-called Fröhlich condition which states that the refractive index of the surrounding medium of a nanoparticle can be used to tune or alter the frequency of the surface plasmon resonance. The equation that relates both properties is as follows:
=== Cephalosporins === After the war ended, Florey directed his team at the Sir William Dunn School in the investigation of antibiotic substances produced by plants and microorganisms. They studied claviformin, proactinomycin, helvolic acid, mycophenolic acid, hirsutic acid, bacitracin and micrococcin. In 1949, they published Antibiotics: A Survey of Penicillin, Streptomycin, and Other Antimicrobial Substances from Fungi, Actinomycetes, Bacteria and Plants, a massive two-volume work. Florey also edited Lectures on General Pathology, which was published in 1954. Chain departed in 1948, but Guy Newton joined the team in his place as its biochemist. Financial support came from the Medical Research Council, the Albert and Mary Lasker Foundation, and American pharmaceutical companies. In September 1953 Newton and Abraham isolated crystalline cephalosporin C from a fungus originally isolated by Giuseppe Brotzu in Sardinia, and found that it had antibiotic properties. Their initial evaluation of the antibiotic activity of cephalosporin C was that it was low, so Abraham sent Florey, who was in Australia, a letter asking if research should continue. Florey saw an intellectually challenging line of research, and told them to continue. They found that it was resistant to penicillinase produced by gram-positive bacteria. When he returned to Oxford, Florey and Jennings conducted a series of experiments that determined that it was not toxic to mice but could protect them against streptococci and penicillinase-producing staphylococci.
Sources: en.wikipedia.org
Devapamil is a calcium channel blocker. It is also known as desmethoxyverapamil, which is a phenylalkylamine (PAA) derivative. Devapamil not only inhibits by blocking the calcium gated channels, but also by depolarizing the membrane during the sodium-potassium exchanges.
Amino acid N-carboxyanhydrides, also called Leuchs' anhydrides, are a family of heterocyclic organic compounds derived from amino acids. They are white, moisture-reactive solids. They have been evaluated for applications the field of biomaterials. NCAs are typically prepared by phosgenation of amino acids: They were first synthesized by Hermann Leuchs by heating an N-ethoxycarbonyl or N-methoxycarbonyl amino acid chloride in a vacuum at 50-70 °C: A moisture-tolerant route to unprotected NCAs employs epoxides as scavengers of hydrogen chloride. This synthesis of NCAs is sometimes called the Leuchs method. The relatively high temperatures necessary for this cyclization results in the decomposition of several NCAs. Of several improvements, one notable procedure involves treating an unprotected amino acid with phosgene or its trimer. NCAs are prone to hydrolysis to the parent amino acid: RCHNHC(O)OC(O) + H2O → H2NCH(R)CO2H + CO2 Some derivatives however tolerate water briefly. NCAs convert to homopolypeptides ( [N(H)CH(R)CO)]n) through ring-opening polymerization:
Gas phase ion chemistry is a field of science encompassed within both chemistry and physics. It is the science that studies ions and molecules in the gas phase, most often enabled by some form of mass spectrometry. By far the most important applications for this science is in studying the thermodynamics and kinetics of reactions. For example, one application is in studying the thermodynamics of the solvation of ions. Ions with small solvation spheres of 1, 2, 3... solvent molecules can be studied in the gas phase and then extrapolated to bulk solution. Transition state theory is the theory of the rates of elementary reactions which assumes a special type of chemical equilibrium (quasi-equilibrium) between reactants and activated complexes. RRKM theory is used to compute simple estimates of the unimolecular ion decomposition reaction rates from a few characteristics of the potential energy surface.
=== Generic names === Doxepin is the generic name of the drug in English and German and its INNTooltip International Nonproprietary Name and BANTooltip British Approved Name, while doxepin hydrochloride is its USANTooltip United States Adopted Name, USPTooltip United States Pharmacopeia, BANMTooltip British Approved Name, and JANTooltip Japanese Accepted Name. Its generic name in Spanish and Italian and its DCITTooltip Denominazione Comune Italiana are doxepina, in French and its DCFTooltip Dénomination Commune Française are doxépine, and in Latin is doxepinum. The cis or (Z) stereoisomer of doxepin is known as cidoxepin, and this is its INNTooltip International Nonproprietary Name while cidoxepin hydrochloride is its USANTooltip United States Adopted Name.
== Contraindications == Persons suffering from acute bleeding, myocardial infarction (heart conditions), hypertension, bradycardia or using alpha or beta receptor agonists should consult with their physician before use. Although toxicology studies have not shown nicergoline to have any teratogenic effect, the use of this medicine during pregnancy should be limited to those cases where it is absolutely necessary. On 28 June 2013, the European Medicines Agency recommended restricting the use of medicines containing ergot derivatives, including nicergoline. They stated that "these medicines should no longer be used to treat several conditions involving blood circulation problems or problems with memory and sensation, or to prevent migraine headaches, since the risks are greater than the benefits in these indications. This is based on a review of data showing an increased risk of fibrosis (formation of excess connective tissue that can damage organs and body structures) and ergotism (symptoms of ergot poisoning, such as spasms and obstructed blood circulation) with these medicines." However, only a subset of ergolines are associated with fibrosis and evidence suggests that nicergoline does not carry the same fibrotic risk like other ergoline derivatives such as ergotamine. Nicergoline is considered unsafe in porphyria.
Sources: en.wikipedia.org
Purity is usually reported as an HPLC area percentage, most often measured at 214 nm. Identity is confirmed separately by mass spectrometry. A certificate of analysis should state both the method and the observed value.
Dry powder is kept frozen, desiccated, and shielded from light. Dissolved material is aliquoted and frozen to limit freeze-thaw cycles. Short-term refrigerated storage is common for working solutions.
Russia registers it as a prescription nasal product. Most other markets classify it as a research chemical with no approved medical use. Oversight of purity and labeling is consequently minimal in those markets.
The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP in one-letter code. It combines the tetrapeptide tuftsin with a carboxyl-terminal Pro-Gly-Pro extension. This full sequence identifies the molecule more precisely than the research name.