If you have been reading about pharmacokinetics 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.
Last reviewed on 2025-12-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
Measuring peptide exposure inside the brain is technically difficult. Selank is degraded rapidly in plasma, and assays must separate intact peptide from fragments, which favors targeted mass spectrometry over immunoassays alone. Reported half-lives are short, on the order of minutes, so effects observed hours later are attributed to downstream signaling rather than to the parent compound. Blood-brain barrier permeability is debated and rarely quantified directly. Gaps include absent dose-response characterization, inconsistent reporting of purity, and almost no pharmacokinetic data from human participants.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
| 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 |
Selank is a synthetic heptapeptide developed in Russia during the 1990s. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences designed it as a stabilized analog of tuftsin, a naturally occurring immunomodulatory tetrapeptide. The compound has been studied primarily for its reported anxiolytic and nootropic effects. It remains largely unknown in Western pharmacology and is not approved as a medicine by major regulators such as the FDA or the EMA.
The primary structure of Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a monoisotopic mass of roughly 751.9 daltons. The N-terminal threonine and the arginine residue in the fourth position are shared with tuftsin, which carries the sequence Thr-Lys-Pro-Arg. The three additional residues at the C-terminus, Pro-Gly-Pro, extend the chain and are associated with greater resistance to enzymatic degradation. This extension also separates Selank from the shorter parent peptide.
Naming conventions place Selank in the same research family as Semax, another Russian-developed peptide investigated for cognitive effects. The two compounds share a lineage but differ in sequence and in the biological systems proposed as their targets. Semax descends from ACTH fragments, whereas Selank descends from tuftsin. Publications sometimes identify Selank by its full peptide sequence or by laboratory codes rather than one uniform trade name. Because replication outside Russia is limited, reports on its properties are best read alongside the study design and the purity of the material tested.
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.
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.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a structural analogue of tuftsin, a naturally occurring tetrapeptide fragment of the immunoglobulin heavy chain. The added Pro-Gly-Pro tail was intended to slow enzymatic degradation and extend biological activity. In Russia it is registered as an anxiolytic nasal preparation, while regulators elsewhere have not approved it for clinical use.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
Selank is a synthetic heptapeptide developed in Russia. Its sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, a seven-residue chain built around the natural tetrapeptide tuftsin. Researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences first described the compound in the mid-1990s. The design combined the tuftsin core with an added Pro-Gly-Pro tail, a modification intended to extend the molecule's stability in biological fluids. Published work on the peptide has appeared mainly in Russian-language journals.
Reported activity for Selank centers on anxiolytic and nootropic effects. Russian clinical reports describe use in anxiety and in cognitive or attention-related complaints. Most of this evidence comes from studies conducted by the same research groups that developed the peptide. Independent replication in other countries remains limited, and no major Western regulatory agency has approved the compound for any indication. The gap between local reports and external verification is a recurring point in discussions of the peptide.
Tuftsin, the parent structure, is a naturally occurring immunomodulatory tetrapeptide released from the Fc region of immunoglobulin G by spleen enzymes. Selank extends this four-residue sequence with three additional amino acids. The stated rationale is that the added tail slows enzymatic breakdown and may influence receptor interactions. How the full heptapeptide behaves at the molecular level is not firmly established, and proposed mechanisms often involve indirect modulation of neurotransmitter or immune signaling rather than a single defined target.
===== Pharmacy logistics and Unit Dose ===== Hospital pharmacies use PTS to expedite medication distribution to wards and automated dispensing points. Integration with Unit Dose packaging and dispensing solutions enables patient-specific, traceable medication flows and supports closed-loop medication management. Industry systems (e.g., TheraPick; Baxter’s unit-dose platforms) and hospital PTS vendors describe end-to-end traceability and secure handover at sending/receiving stations.
== Formulations == All formulations of co-dydramol contain 500 mg of paracetamol per tablet and may only be sold at a pharmacy as an over-the-counter item without prescription (a P medicine) if containing less than 7.5 mg of dihydrocodeine per tablet. Higher strengths are prescription only medicines. There are no GSL formulations of co-dydramol, as it is a Schedule 5 controlled drug. Four strengths of dihydrocodeine tartrate in each tablet are available:
He pointed out that the TRIPS agreement signed by all members of the WTO already allows for an emergency waiver of intellectual property rights in countries with free manufacturing capacities. Several observers have noted that the vaccine patent waiver debate involves an issue expected to outlast the COVID-19 pandemic: who will control the broader technology of RNA therapeutics. Howard Dean has accused Narendra Modi of trying to gain access to such technology by promoting the "disingenuous" claim that patent waivers will accelerate vaccine production. Josh Rogin has pointed out that control of mRNA technology has "national security implications" for the United States, and that its development was initially funded by U.S. taxpayers through DARPA for that reason. Central to the debate is whether profits from strong intellectual property rights are necessary to ensure that someone will conduct the applied research which turns promising laboratory experiments into marketable drugs and vaccines. Such research is dauntingly expensive (on average, $3 billion per successful drug) and nearly always fails (only 12 percent of drugs which enter clinical trials ultimately obtain FDA approval), and "governments have neither the money nor the risk tolerance to take over the role of businesses in developing pharmacy-ready medicines". Moderna co-founder Robert S. Langer has argued that early private investors deserve "a lot of credit" for its successful COVID-19 vaccine since they "put the money in way before" the U.S.
=== Secondary Sources === Blackmore, Tim (2010), "Save Now [Y/N]? Machine Memory at War in Iain M. Banks' Look to Windward", Bulletin of Science, Technology & Society, 30 (4): 259–273, doi:10.1177/0270467610373816, ISSN 0270-4676, S2CID 144415805 Brown, Chris (2001), "'Special Circumstances': Intervention by a Liberal Utopia", Millennium – Journal of International Studies, 30 (3): 625–626, doi:10.1177/03058298010300031601, S2CID 143328512. Horwich, David (21 January 2002), "Culture Clash: Ambivalent Heroes and the Ambiguous Utopia in the Work of Iain M. Banks", Strange Horizons, retrieved 3 August 2021. Jackson, Patrick Thaddeus; Heilman, James (2008), "Outside Context Problems: Liberalism and the Other in the Work of Iain M.Banks", in Hassler, D.M.; Wilcox, C. (eds.), New Boundaries in Political Science Fiction, University of South Carolina Press, pp. 235–258, ISBN 978-1-57003-736-8, retrieved 9 December 2008. Lippens, Ronnie (2002), "Imachinations of Peace: Scientifictions of Peace in Iain M. Banks's The Player of Games", Utopian Studies, 13 (1): 135–147, ISSN 1045-991X, OCLC 5542757341. Newitz, Annalee (2019), The future of another timeline, Little, Brown Book Group Limited, ISBN 978-0-356-51123-8, OCLC 1059268855. Norman, Joseph S. (2021), The Culture of "The Culture": Utopian Processes in Iain M. Banks's Space Opera Series, Oxford University Press, ISBN 978-1-78962-174-7, OCLC 1120943463. Rumpala, Yannick (2012), "Artificial intelligences and political organization: An exploration based on the science fiction work of Iain M.
Sources: en.wikipedia.org
Benzylmorphine (Peronine) is a semi-synthetic opioid narcotic introduced to the international market in 1896 and that of the United States very shortly thereafter. It is much like codeine, containing a benzyl group attached to the morphine molecule just as the methyl group creates codeine and the ethyl group creates ethylmorphine or dionine (used as a generic name for that drug just as peronine is for benzylmorphine). It is about 90% as strong as codeine by weight. This drug, the benzyl ether of morphine, should not be confused with dibenzoylmorphine, an ester of morphine comparable to heroin. Another morphine ether developed around the same time, benzyldihydromorphine, saw some clinical use in the opening years of the 20th century. The ethers of morphine and codeine as well as dihydromorphine and dihydrocodeine number close to 100 and include such obscure opioids as formylallopseudoisocodeine. Benzylmorphine is used in much the same way as codeine and ethylmorphine, primarily as a moderate strength analgesic, for eye surgery as a 1 to 2% solution, and as a cough suppressant. It was available in the United States prior to 1914 and was still used until the 1960s, but fell into disuse once alternative opiate derivatives became preferred by doctors (i.e. hydrocodone as an analgesic and codeine as a cough suppressant) Benzylmorphine is now a Schedule I Controlled Substance in the US and is regulated internationally under UN drug conventions. Benzylmorphine is an active metabolite of the opioid analgesic myrophine, formed in the liver.
Furthermore, Atracium produces a toxic metabolite called laudanosine when administered and can accumulate in patients with impaired renal function. This may lead to potential seizures and epilepsy. Thus, the dosage of the atracium should be compensated for patients with decreased renal functions. Vecuronium: Most of vecuronium's adverse effects is correlated to the drug's extension of pharmacological effects past the desired time of use. Serious adverse effects include bronchospasm, anaphylaxis, apnea, and prolonged paralysis. In some instances, hypersensitivity-associated histamine release may occur, leading to allergy-like symptoms or severe anaphylaxis in rare cases. Vecuronium has a relatively favourable safety profile when compared to pancuronium or other aminosteroid non-depolarizing drugs. Pancuronium: Pancuronium produces more significant adverse effects due to the blockade of muscarinic M2 receptors in the atria. Therefore, pancuronium may increase cardiac output, mean arterial pressure, and heart rate. To add on, patients with renal failure may experience a 30-50% decrease in plasma clearance, hence an increase in neuromuscular blockade duration. The use of pancuronium with insufficient anesthetic agents leads to morbidity and psychological trauma. Acetylcholinesterase inhibitor Donepezil: Donepezil may exhibit cardiac issues such as hypertension, cardiac arrhythmia, atrioventricular block, and bradycardia due to its vagotonia properties.
=== July === July 1 Recreational cannabis becomes legal in Connecticut and Virginia. Medical cannabis becomes legal in South Dakota. COVID-19 vaccination – Michigan Governor Gretchen Whitmer announces a month-long vaccination raffle in which residents can win a total of $5 million in cash (one grand prize of $2 million or three prizes of $1 million) and $500,000 total in college scholarships for children ages 12–17 years old (nine prizes of $55,000). The winners were drawn on August 4. July 2 – Hundreds of businesses are hit by a large-scale cyberattack, linked to the Russian REvil ransomware gang. July 2–5 – At least 233 people were killed and 618 people were injured in over 500 shootings nationwide during the Independence Day weekend. July 6 – 2021 New York City mayoral election – Eric Adams was declared the winner of the Democratic primary for mayor of New York City. July 7 – The Tampa Bay Lightning defeat the Montreal Canadiens (4-1) in the 2021 Stanley Cup Finals to win their second consecutive Stanley Cup. July 8 – Attorney Michael Avenatti is sentenced to 2.5 years in prison for attempting to extort Nike. July 9 Twitter suspensions – Twitter announces that they have suspended political commentator and nationalist Nick Fuentes. President Biden signs a 72-point executive order placing tighter regulations and scrutiny on major corporations in a variety of sectors, including Big Tech companies.
Sources: en.wikipedia.org
== Etymology == The name Pakistan was coined by Choudhry Rahmat Ali, a Pakistan Movement activist, who in January 1933 first published it (originally as "Pakstan") in a pamphlet Now or Never, using it as an acronym. Rahmat Ali explained: "It is composed of letters taken from the names of all our homelands, Indian and Asian, Panjab, Afghania, Kashmir, Sindh, and Baluchistan." He added, "Pakistan is both a Persian and Urdu word... It means the land of the Paks, the spiritually pure and clean." Etymologists note that پاک pāk, is 'pure' in Persian and Pashto and the Persian suffix ـستان -stan means 'land' or 'place of'. Rahmat Ali's concept of Pakistan only related to the northwestern area of the Indian subcontinent. He also proposed the name "Banglastan" for the Muslim areas of Bengal and "Osmanistan" for Hyderabad State, as well as a political federation between the three.
=== Paradoxical effects === Flunitrazepam may cause a paradoxical reaction in some individuals, including anxiety, aggressiveness, agitation, confusion, disinhibition, loss of impulse control, talkativeness, violent behavior, and even convulsions. Paradoxical adverse effects may even lead to criminal behaviour.
=== Modification after heptapeptide backbone formation === Once the heptapeptide backbone has been formed, the linear enzyme-bound intermediate is cyclized. Gene disruption studies indicate cytochrome P450 oxygenases as the enzymes that performs the coupling reactions. The X-domain in the final NRPS module is required to recruit the oxygenase enzymes. OxyB forms the first ring by coupling residues 4 and 6, and OxyE then couples residues 1 and 3. OxyA couples residues 2 and 4, followed by the formation of a C-C bond between residues 5 and 7 by OxyC. The regioselectivity and atropisomer selectivity of these probable one-electron coupling reactions has been suggested to be due to the folding and orientation requirements of the partially crossed-linked substrates in the enzyme active site. The coupling reactions are shown below.
=== Warnings and precautions === In December 2013, the FDA added warnings to the label for clobazam, that it can cause serious skin reactions, Stevens–Johnson syndrome, and toxic epidermal necrolysis, especially in the first eight weeks of treatment.
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.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.