What is Selank + Semax Nasal Spray?
Selank is H-Thr-Lys-Pro-Arg-Pro-Gly-Pro-OH, CAS 129954-34-3, formula C33H57N11O9, molecular weight 751.88, a seven-residue analogue of the immunomodulatory fragment tuftsin. Semax is H-Met-Glu-His-Phe-Pro-Gly-Pro-OH, CAS 80714-61-0, formula C37H51N9O10S, molecular weight 813.92, an analogue of the ACTH(4-7) fragment extended with a Pro-Gly-Pro tail. Both share that C-terminal tripeptide, a design feature reported to slow serum peptidase cleavage, and both are small, hydrophilic and highly water soluble.
The spray is a delivery format rather than a new molecule. Nasal and mucosal administration is a well developed area of formulation science, since the respiratory epithelium is thin, densely vascularized and avoids first-pass hepatic metabolism in absorption models. Transmucosal permeability for peptides in this mass range is low but measurable, and both of these molecules were originally developed and studied in intranasal preparations, so the published rodent work on them is largely tied to this route.
What is not established is the quantitative side. Published transmucosal bioavailability figures for short peptides vary widely with pH, tonicity, viscosity and contact time. Combining two peptides in one vehicle also raises questions of competitive absorption that have not been studied for this pair.
Reconstitution & handling
No reconstitution step applies, since the peptides arrive already dissolved in a buffered isotonic vehicle. Concentration math works from the label instead. Total peptide content divided by fill volume gives nominal concentration, and dividing again by the metered volume per actuation gives mass per actuation. The bottle should not be diluted, since buffer and tonicity are part of the formulation.
Storage & stability
Sealed bottles are stored refrigerated at 2 to 8 degrees Celsius and protected from light, because peptides in aqueous solution are less stable than the same molecules lyophilized. Freezing is avoided, since ice formation concentrates solutes and can drive aggregation. The N-terminal methionine of the Semax component is oxidation prone, which is the main chemical liability of this pair and the reason headspace is limited.
How it's tested
Solution lots are assayed by reverse-phase HPLC at 214 and 220 nanometres, resolving two peaks quantified against reference standards to confirm the declared 5 mg and 5 mg content. Mass spectrometry verifies identity against theoretical masses of 751.88 and 813.92, and the same run detects the Semax sulfoxide oxidation product. Fill volume, pH and sterility are recorded.