intranasal delivery comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-05-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
Common degradation pathways include oxidation of the methionine side chain, hydrolysis of the peptide backbone, and aggregation under unfavourable pH or concentration. Stability studies typically monitor the main peak by chromatography and report total related substances as a percentage. Because no official monograph exists, acceptance criteria vary between laboratories, and reported purity values are not directly comparable across suppliers. Analysts therefore document the method, column, and detection wavelength alongside each result, and open questions remain about how much biological activity the oxidised forms retain.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical analytical method | Reversed-phase HPLC with UV detection | Separates target peptide from truncated and oxidised forms |
| Identity confirmation | LC-MS or ESI-MS | Compares observed and calculated molecular ion |
| Primary degradation route | Methionine oxidation | Forms the sulfoxide; monitored as an early-eluting peak |
| Short-term storage | 2 to 8 degrees Celsius | Applies to working vials and reconstituted portions |
| Common synonyms | ACTH(4–10) analogue, MEHFPGP | Descriptive names used in laboratory catalogues |
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.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
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.
Clinical evidence consists largely of small trials with modest sample sizes, often without independent replication. Reported endpoints include cognitive scores, recovery after stroke, and visual function, but study designs vary widely and few trials meet contemporary reporting standards. Systematic reviewers have noted a high risk of bias in several of these reports. No large multicenter trial conducted outside Russia has been published. The compound is therefore best described as investigational in most jurisdictions, with its clinical role still unresolved.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Once dissolved, the peptide is considerably less stable than the solid. Aqueous solutions are usually prepared at neutral to slightly acidic pH, filtered, and divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are a common cause of avoidable loss and are best prevented by never refreezing a thawed aliquot. Adsorption to plastic and glass surfaces can lower the measured concentration of dilute solutions, particularly below roughly 0.1 mg/mL. Buffer choice, salt content, and container material all influence how much peptide remains detectable after storage.
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.
Both lepa1 and lepa2 have two characteristic cysteine residues which predict the formation of a disulfide bond in Lep, which is a pre-equisite for this 3D configuration and bioactivity of human LEP. The models suggest that the bonding of lepa2 might be different from lepa1. There are several differences between the 3D structures of lepa1 and lepa2; e.g. α-helix 5 is considerable shorter in lepa1 than lepa2. Furthermore, α-helix 1 for lepa2 appears to be split by a short-disordered region, and may therefore have a poorer affinity. However, considering that it is a predicted model based upon the structure mask of human LEP, the significance of these putative conformational adjustments remains to be tested. The importance of the conserved tertiary structure of Lep is most likely explained by requirements for specific LepR-binding affinity and is constrained by the structure of the receptor-binding pocket. This might also explain some of the results from studies on teleost using heterologous mammalian Lep. E.g. treatment with the mammalian hormone caused an anorexic effect in goldfish (Carassius auratus) and green sunfish (Lepomis cyanellus), but not in Coho salmon (Oncorhynchus kisutch), channel catfish (Ictalurus punctatus) and green sunfish. These contradicting results have been explained by the relatively large differences in amino acid sequences observed between mammals and fish. Rønnestad and colleagues recently detected five isoforms of the leptin receptor (lepr) that have differences in 3'-end of the mRNA sequence.
Sheikha Fatima bint Hazza bin Zayed Al Nahyan. Sheikha Salama bint Hazza bin Zayed Al Nahyan. Sheikh Zayed bin Hazza bin Zayed Al Nahyan (born 1995). He has one son. Sheikh Hazza bin Zayed Al Nahyan (born 2026). Sheikha Meera bint Hazza bin Zayed Al Nahyan. She married Sheikh Zayed bin Mansour bin Zayed Al Nahyan on May 5, 2022. Sheikh Mohammed bin Hazza bin Zayed Al Nahyan (born 2002).
== Religious function == The ability of pigmented strains of Serratia marcescens to grow on bread has led to a possible explanation of Medieval transubstantiation miracles, in which Eucharistic bread is converted into the Body of Christ. Such miracles led to Pope Urban IV instituting the Feast of Corpus Christi in 1264. This followed celebration of a Mass at Bolsena in 1263, led by a Bohemian priest who had doubts concerning transubstantiation. During the Mass, the eucharist appeared to bleed and each time the priest wiped away the blood, more would appear. This event is celebrated in a fresco in the Pontifical Palace in the Vatican City, painted by Raphael: The Mass at Bolsena.
== History == Leveraging advanced computational bioinformatics, brilacidin and other defensin mimetics were first developed by University of Pennsylvania-based researchers. Their efforts were consolidated, and officially incorporated, in 2002, under the company name PolyMedix. PolyMedix conducted pre-clinical and clinical research with brilacidin through a completed Phase 2a human clinical trial with positive results. After discontinuing a clinical trial for an unrelated compound PolyMedix filed for Chapter 7 bankruptcy protection on 1 April 2013. Cellceutix acquired the PolyMedix assets and intellectual property, including the licenses and patents for brilacidin and the rest of the HDP-mimetic pipeline, from bankruptcy court which on 4 September 2013, approved Cellceutix's stalking horse bid. On 7 June 2017, Cellceutix Announced a Company Name Change to Innovation Pharmaceuticals Inc. On 9 June 2017, the stock ticker name was effectively changed to "IPIX".
Sources: en.wikipedia.org
=== Fruit === The fruit is generally a wind-dispersed capsule, but occasionally a berry (Medeoleae) which is dispersed by animals. A capsule that is usually loculicidal (splitting along the locules) as in the Lilioideae, but occasionally septicidal (splitting between them, along the separating septa) in the Calachortoideae and wind dispersed, although the Medeoleae form berries (baccate). The seeds may be flat, oblong, angular, discoid, ellipsoid or globose (spherical), or compressed with a well developed epidermis. The exterior may be smooth or roughened, with a wing or raphe (ridge), aril or one to two tails, rarely hairy, but may be dull or shiny and the lack of a black integument distinguishes them from related taxa such as Allioideae that were previously included in this family, and striate (parallel longitudinally ridged) in the Steptopoideae. The hilum (scar) is generally inconspicuous. The bitegmic (separate testa and tegmen) seed coat itself may be thin, suberose (like cork), or crustaceous (hard or brittle). The endosperm is abundant, cartilaginous (fleshy) or horny and contains oils and aleurone but not starch (non-farinaceous). Its cells are polyploid (triploid or pentaploid, depending on the embryo sac type). The embryo is small (usually less than one quarter of seed volume), axile (radially sectioned), linear (longer than broad) or rarely rudimentary (tiny relative to endosperm) depending on placentation type, and straight, bent, curved or curled at the upper end.
epitope Also antigenic determinant. The specific site or region within an antigenic macromolecule such as a protein or carbohydrate which is recognized by B or T cells of the immune system, against which a specific antibody is produced, and with which the antibody's paratope specifically interacts or binds. In proteins, epitopes are typically motifs of 4–5 amino acid residues, sequential or discontiguous, which by virtue of the distinct spatial conformation they adopt upon protein folding are able to uniquely interact with a particular paratope. In this sense they may be considered binding sites, though they do not necessarily overlap with ligand binding sites and need not be in any way relevant to the protein's normal function. Very large molecules may have multiple epitopes, each of which is recognized by a different antibody.
Ehrenfreund et al. (2001) found that amino acids in CI chondrites Ivuna and Orgueil were present at much lower concentrations than in CM chondrites (~30%), and that they had a distinct composition high in β-alanine, glycine, γ-ABA, and β-ABA but low in α-aminoisobutyric acid (AIB) and isovaline. This implies that they had formed by a different synthetic pathway, and on a different parent body from the CM chondrites.
Sources: en.wikipedia.org
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.
Oxidation of the methionine residue to the sulfoxide is a frequently reported change, and it usually appears as an earlier-eluting peak in reversed-phase chromatography. Backbone hydrolysis products can also accumulate in aqueous solution.
Liquid chromatography coupled with mass spectrometry is the usual approach, because the observed molecular ion can be compared with a calculated mass of about 813.9 Da. Retention time alone does not establish identity.
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.