How Much Bacteriostatic Water for a Selank 10 mg Vial?
A 10 mg vial of Selank reconstituted with 2 mL of bacteriostatic water gives a concentration of 5 mg/mL; with 1 mL it gives 10 mg/mL. The calculation depends only on the quantity in the vial and the volume of water added, so the figures below apply to any 10 mg vial.
Voir le produit →There is no single correct volume. Adding more water does not change how much is in the vial. It spreads the same quantity through a larger volume, which changes how many syringe units correspond to a given amount. The tables on this page use volumes that produce round numbers on a U-100 syringe; other volumes work identically as long as the resulting concentration is written on the vial.
Concentration by water volume
Concentration is the quantity in the vial divided by the water volume. A 10 mg vial holds 10 mg whether it receives 1 mL or 5 mL; only the mg/mL figure moves. The right-hand column converts each concentration into the number of U-100 units that contain 1 mg.
| Vial | Bacteriostatic water added | Concentration | Units containing 1 mg |
|---|---|---|---|
| 10 mg selank | 1 mL | 10 mg/mL | 10 units |
| 10 mg | 2 mL | 5 mg/mL | 20 units |
| 10 mg | 3 mL | 3.33 mg/mL | 30 units |
| 10 mg | 5 mL | 2 mg/mL | 50 units |
Before choosing a larger volume, check that the vial has headspace for it. A 10 mL vial of bacteriostatic water reconstitutes five 10 mg vials at 2 mL each.
Reading the concentration on a U-100 syringe
A U-100 insulin syringe is graduated in units, and 100 units equal 1 mL. Units are therefore millilitres multiplied by 100: 0.1 mL is 10 units and 0.25 mL is 25 units. A 0.5 mL syringe carries 50 units and a 0.3 mL syringe carries 30 units on the same scale, with finer markings that make small volumes easier to read.
To find the volume that contains a given amount, divide the amount by the concentration. At 5 mg/mL (a 10 mg vial with 2 mL of water), the volume that contains 1 mg is 1 divided by 5, which is 0.2 mL, or 20 units. The table below runs the same calculation for four arbitrary amounts. They illustrate the arithmetic and nothing else.
| Amount (illustrative) | Volume at 5 mg/mL | U-100 units |
|---|---|---|
| 0.25 mg | 0.05 mL | 5 units |
| 0.5 mg | 0.1 mL | 10 units |
| 1 mg | 0.2 mL | 20 units |
| 2 mg | 0.4 mL | 40 units |
At 10 mg/mL, which the same vial gives with 1 mL of water, every volume in the table moves in proportion: a 1 mg draw measures 10 units instead of 20. Volumes below about 0.1 mL are hard to read accurately on a 1 mL syringe. Either move to a 0.3 mL or 0.5 mL syringe, or reconstitute with more water so that the same mass occupies a larger, more legible volume.
Selank is supplied by Vistara Labs as a lyophilised material for research use. The quantities on this page illustrate the arithmetic of dilution and measurement only.
The Selank vial
Selank is a heptapeptide: the four-amino-acid tuftsin sequence with a Pro-Gly-Pro tail that slows its breakdown. This page covers the 10 mg lyophilised vial. Certificates of analysis for the catalogue are published on the Résultats de laboratoire page. The Vaporisateur nasal Selank is supplied pre-mixed and needs no reconstitution; this page is for the lyophilised vial only.
Tuftsin, the four-residue core of Selank, is broken down within minutes in blood; the Pro-Gly-Pro tail is what makes Selank durable enough to study. It is a small molecule by peptide standards, so a 10 mg vial holds far more individual molecules than 10 mg of a large peptide such as tesamorelin, though the mass-based tables apply unchanged. For reference, each 10 mg bottle of the spray delivers roughly 28 metered sprays at 350 mcg per spray. The clinical studies are covered in Selank and anxiety: the research.
Reconstitution technique
Let the vial reach room temperature, swab both stoppers, and run the measured water slowly down the inside wall of the vial rather than onto the powder. Swirl or tilt gently until the cake dissolves, never shake, and give any remaining powder a few minutes to settle into solution. Label the vial with the date and the concentration, then keep it refrigerated at 2 to 8 °C and protected from light. The full method, with the reason behind each step, is in l'achat d'eau bactériostatique au Canada.
Why the solution should look clear
Properly reconstituted Selank forms a clear, colourless solution. Cloudiness, strands or a gel that will not disperse usually mean the water went in too fast or the vial was shaken; haze that appears later points to warm or bright storage. The causes are covered in why peptides gel or go cloudy.
Bacteriostatic water, not sterile water
Bacteriostatic water is sterile water with 0.9% benzyl alcohol, a preservative that allows a refrigerated vial to be accessed more than once; plain sterile water is intended for single access. The difference is explained in bacteriostatic water explained.
Questions fréquentes
How much bacteriostatic water do I add to a 10 mg vial of Selank?
There is no single correct volume. With 2 mL of bacteriostatic water a 10 mg vial of Selank gives 5 mg/mL; with 1 mL it gives 10 mg/mL. Adding more water does not change the quantity in the vial, it spreads it through a larger volume, so write the concentration you chose on the vial.
How many 10 mg vials does a 10 mL vial of bacteriostatic water cover?
A 10 mL vial of bacteriostatic water reconstitutes five 10 mg vials at 2 mL each. Check that the peptide vial has headspace for the volume before choosing a larger one.
How many units on a U-100 syringe contain 1 mg at 5 mg/mL?
At 5 mg/mL (a 10 mg vial with 2 mL of water), the volume that contains 1 mg is 1 divided by 5, which is 0.2 mL, or 20 units. Units are millilitres multiplied by 100, so 0.1 mL is 10 units. The amounts on this page illustrate the arithmetic only.
What should reconstituted Selank look like?
Properly reconstituted Selank forms a clear, colourless solution. Cloudiness, strands or a gel that will not disperse usually mean the water went in too fast or the vial was shaken; haze that appears later points to warm or bright storage. More on the causes in why peptides gel or go cloudy.
Can I use sterile water instead of bacteriostatic water?
Only for a vial that will be accessed once. Bacteriostatic water is sterile water with 0.9% benzyl alcohol, a preservative that allows a refrigerated vial to be accessed more than once; plain sterile water is intended for single access. Details in bacteriostatic water explained.
How should a reconstituted Selank vial be stored?
Refrigerated at 2 to 8 °C, protected from light and labelled with the date and the concentration. Unopened lyophilised vials are kept cold and dark until they are needed. The full storage guide is how to store research peptides.
Work it out for a different vial or concentration
Our calculateur de peptides opens pre-set for a 10 mg vial with 2 mL of water and marks the 1 mg draw of 20 units on a syringe diagram. Change the vial size, water volume, amount or syringe and it recalculates.
Products: Selank 10 mg et bacteriostatic water 10 mL.
Références
Le Selank a été évalué dans de petites études comparatives humaines sur les troubles liés à l'anxiété, pas dans de grands essais multicentriques contrôlés par placebo.
- [Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia]Étude clinique comparative; 30 patients sous Selank contre 32 sous médazépam.
- [A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders]Étude clinique comparative; 60 patients avec troubles anxieux ou somatoformes, Selank contre phénazépam.
Les liens ouvrent la fiche de l'étude sur PubMed afin que la source puisse être vérifiée directement. Citer une étude ne signifie pas que ses résultats s'appliquent à un autre usage, produit ou mode d'administration. Usage laboratoire uniquement.
