Dosage research on Selank

Preclinical research dose ranges

In published preclinical research on Selank, administered dose ranges in rodent studies have most commonly fallen in the 100 to 1000 microgram per kilogram range delivered intranasally or intraperitoneally. The anxiolytic-endpoint literature in rats and mice has used doses in this span across acute and sub-chronic dosing protocols, with the lower end of the range producing the more characteristic anxiolytic profile in elevated-plus-maze and open-field tests.

The cognitive-endpoint literature has used a comparable dose range, with doses in the microgram-per-kilogram range delivered intranasally or intraperitoneally in passive-avoidance and active-avoidance learning models. The cytokine-and-immune-marker line of investigation has used doses in the same range across multi-day observation windows for blood-marker time-course measurement.

The Kozlovskaya and colleagues line of work characterised the immunomodulatory and anxiolytic profile across this dose range in rodent models. Investigators reading the Selank literature should note the Russian-laboratory tradition of per-animal versus per-kilogram dose reporting and translate to per-kilogram equivalents using the reported animal body weights when comparing across literatures.

Dose-response considerations from the published literature

The published Selank literature has reported dose-response characteristics in anxiolytic endpoints across the 100 to 1000 microgram per kilogram range in rodent models, with the lower-end doses producing the more characteristic anxiolytic profile. Higher doses in some protocols produce mixed-profile effects that the published work attributes to broader-spectrum neuropeptide pathway engagement.

A small number of Russian clinical-pilot reports exist in the neuropeptide and anxiolytic literature using doses in the microgram-per-day range intranasally in adult subjects. These reports do not constitute Phase 1 dose-ranging trials, and the research community continues to rely on the rodent literature and these pilots for dose-design inference.

Reconstitution math and per-vial dose calculation

A 10 mg lyophilised Selank vial reconstituted with 2 mL of bacteriostatic water yields a stock concentration of 5 mg per mL. From this stock, a research aliquot of 0.1 mL contains 500 micrograms; an aliquot of 0.02 mL contains 100 micrograms. Researchers working with the microgram-per-kilogram dose ranges in published rodent studies further dilute the stock to a working concentration appropriate to the model and the body weight of the animal subject. For intranasal administration, the working concentration is typically further diluted to the small-volume delivery range appropriate to per-nostril dosing. Refrigerated storage at 2 to 8 degrees Celsius, protected from light, is the standard handling practice.

Research-protocol design considerations

Protocol-design choices in the published Selank literature reflect several recurring considerations. Dose selection in rodent anxiolytic studies anchors at the 100 to 1000 microgram per kilogram range. Acute single-dose protocols predominate in elevated-plus-maze and open-field test designs; sub-chronic multi-day protocols appear in cytokine and immune-marker time-course studies.

Route of administration in the published rodent work uses both intranasal and intraperitoneal injection. Intranasal administration matches the delivery route used in the human pilot reports and exploits the nose-to-brain delivery considerations relevant to central-nervous-system endpoints. Intraperitoneal administration appears in systemic-endpoint and pharmacokinetic studies.

The Russian-laboratory research tradition is a protocol-design consideration unique to Selank and a few other Russian-developed peptides. Investigators outside the Russian research tradition reading the Selank literature should note the per-animal versus per-kilogram dose convention difference and the model-system differences that may complicate direct comparison with Western preclinical research on neuropeptide anxiolytics.

References

1. Kozlovskaya MM et al. Selank and short peptides of the tuftsin family in the regulation of adaptive behavior in stress. Neuroscience and Behavioral Physiology, 2003. [PMID 12669588]
2. Sollertinskaya TN et al. The compensatory and adaptive role of the peptide selank in vegetative disorders in monkeys. Russian Journal of Physiology, 2008. [PMID 18610703]
3. Volkova A et al. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Frontiers in Pharmacology, 2016. [PMID 26869933]
4. Kolomin TA et al. Transcriptomic response of rat hippocampus and spleen cells to single Selank administration. Molecular Biology, 2013. [PMID 23808162]
5. Vyunova TV et al. Peptide-based anxiolytics: the molecular aspects of heptapeptide selank biological activity. Protein and Peptide Letters, 2018. [PMID 29637862]
6. Semenova TP et al. Selank and short peptide regulation of cortex and hippocampal monoaminergic systems. Bulletin of Experimental Biology and Medicine, 2009. [PMID 19526121]