Intranasal Research
Peptide Preparation Guide

Intranasal Peptide Research: Overview

Intranasal administration is a delivery route studied in preclinical research for peptides where access to the central nervous system is part of the research question. The olfactory and trigeminal nerve networks provide an anatomical pathway in animal models that differs from systemic routes, which is why intranasal delivery appears frequently in research literature on nootropic and neuroprotective compounds.

In a laboratory context, preparing a compound for intranasal research involves dissolving the lyophilised peptide into a saline or bacteriostatic water solution and loading it into a spray device for use in the relevant research model. All steps described in this guide are for research preparation purposes only. These materials are not for human or animal consumption.

Compounds Studied in Intranasal Research Models

Several research compounds in the North Peptides UK catalogue appear in the published intranasal research literature. The two most frequently referenced are Semax and Selank — both heptapeptides studied in preclinical CNS models.

Both are synthesised as stable heptapeptides. Semax carries a Pro-Gly-Pro C-terminal extension that increases stability versus the parent ACTH(4-7) sequence. Selank is structurally related to the endogenous immunomodulatory peptide tuftsin. Published preclinical studies on both compounds have used intranasal administration as the delivery route in the research model.

Equipment: The Intranasal Research Kit

The Intranasal Research Kit from North Peptides UK includes the components needed to prepare a research compound as an intranasal spray preparation:

• 10ml nasal spray bottle — calibrated spray mechanism for repeatable volumes in research preparations
• Sterile 0.9% saline ampoule — the standard solvent used in intranasal preclinical research preparations
• Transfer syringe and fill adaptor — for accurately transferring the reconstituted solution into the spray bottle
• Alcohol wipes — for wiping vial stoppers and working surfaces before preparation
• Blank label — for recording the compound name, concentration and preparation date

The lyophilised peptide vial is required separately. Semax and Selank are the compounds most commonly prepared in this format from the North Peptides UK range.

Preparation Steps

The following steps describe preparing a lyophilised research peptide as an intranasal spray preparation for laboratory use. All steps describe preparing research material — not guidance for human or animal use.

1. Allow the peptide vial to reach room temperature. Remove the vial from the freezer or refrigerator and leave it for 15–20 minutes before opening. This prevents condensation forming inside the vial and the powder clumping.
2. Wipe the vial stopper. Use an alcohol wipe on the rubber stopper of the peptide vial and allow 10 seconds to air dry.
3. Draw up the saline. Using the transfer syringe, draw the required volume of 0.9% sterile saline. The volume of solvent added to the vial determines the concentration of the prepared research solution (see the concentration reference table below).
4. Add the saline slowly to the peptide vial. Direct the solvent down the inside wall of the vial rather than straight onto the powder, to avoid foaming. Gently swirl rather than shake until the powder fully dissolves and the solution is clear.
5. Transfer the solution to the spray bottle. Draw the prepared solution into the syringe using the fill adaptor and fill the nasal spray bottle. Label the bottle with the compound name, concentration and preparation date.
6. Store correctly. Refrigerate the prepared spray at 2–8°C away from direct light. Keep the cap in place between uses and discard after the appropriate shelf-life window.

Concentration Reference for Intranasal Research Preparations

The concentration of a prepared intranasal research solution depends on the volume of solvent added to the lyophilised vial. The table below shows the resulting concentration for the two compounds most commonly prepared in this format:

These figures describe the concentration of research material dissolved in the vial. They are a property of the solution itself, not directions for use in humans or animals.

Saline vs Bacteriostatic Water for Intranasal Preparations

Both sterile saline and bacteriostatic water are used to reconstitute peptides for research preparations. Each has different characteristics relevant to laboratory workflows:

For research preparations that will be drawn from across multiple sessions, bacteriostatic water is the standard choice, as the benzyl alcohol suppresses microbial contamination in the prepared solution.

Storage and Handling of Prepared Intranasal Research Preparations

• Refrigerate at 2–8°C between research sessions. Store the spray bottle upright and away from direct light.
• Do not freeze a prepared solution — freezing damages the peptide structure. Keep the compound as lyophilised powder for long-term storage and prepare only the volume required for the current research session.
• Label the spray bottle with the compound name, concentration and preparation date. If both Semax and Selank are in use simultaneously, clear labelling is essential to prevent mix-ups.
• Shelf life: Discard after 28 days (bacteriostatic water preparation) or after approximately 24 hours (saline preparation).

For general guidance on storing peptides in both lyophilised and reconstituted forms, see the peptide storage guide. For reconstitution technique, see the reconstitution guide.

Frequently Asked Questions