What is Selank + Semax Dissolving Strips?
The peptides are the same two characterized elsewhere in this library. Selank is H-Thr-Lys-Pro-Arg-Pro-Gly-Pro-OH, CAS 129954-34-3, formula C33H57N11O9, molecular weight 751.88. Semax is H-Met-Glu-His-Phe-Pro-Gly-Pro-OH, CAS 80714-61-0, formula C37H51N9O10S, molecular weight 813.92. Both are seven residues, both end in the stabilizing Pro-Gly-Pro tail, and both are hydrophilic, which suits them to dispersion in a water-soluble film rather than a lipid matrix.
Orally dissolving films are a well described formulation class. A hydrophilic film former such as hypromellose or pullulan is combined with a plasticizer, the peptide is dissolved into the casting solution, and solvent is evaporated to leave a uniform sheet that is die-cut into strips. The format is studied because it places a defined mass of solute against a mucosal surface with a short disintegration time, and because a dried film has low water activity, which slows the hydrolysis that limits peptides in solution.
What is not settled is transmucosal recovery. Published absorption fractions for peptides delivered from films vary with thickness, polymer choice and disintegration time, and do not transfer automatically between species or formulations. This specific two-peptide film has no published comparative study.
Reconstitution & handling
No reconstitution applies, since the format is a dry solid rather than a lyophilized powder. The analytical equivalent is extraction. A strip is dissolved in a measured volume of buffer or a water and acetonitrile mixture, agitated until the matrix disperses, then filtered to remove film-former residue. Concentration follows from labeled content per strip divided by extraction volume.
Storage & stability
Strips are kept in their sealed moisture-barrier pack at controlled room temperature or refrigerated at 2 to 8 degrees Celsius, away from light and humidity, because the matrix is hygroscopic and a film that absorbs moisture turns tacky and loses its disintegration profile. Freezing is unnecessary and risks condensation when the pack is reopened. The N-terminal methionine of the Semax component remains the main oxidative liability.
How it's tested
Content uniformity is the governing test for a film format. Strips are extracted and assayed by reverse-phase HPLC at 214 and 220 nanometres, with mean content and strip-to-strip variation reported against the declared per-strip figures. Mass spectrometry confirms identity against theoretical masses of 751.88 and 813.92, and the same run separates the Semax sulfoxide. Disintegration time is recorded per lot.