Your right Rossum just checked out Wizardlabs and couldn't find anything on adding gas. Since they're saying "recommend transferring your nicotine solution into glass containers" below & stating that it can be stored over two years. Nude is the way to go for long storage plus it's packed in bottles.
Wizard Labs Nicotine solutions are shipped in chemically resistant plastic containers for shipping safety, and heat sealed in multiple containment bags to prevent leakage during shipment. For long term storage over 2 months, we recommend transferring your nicotine solution into glass containers with airtight lids, and as little airspace in the top of the container as possible. If stored properly, in a freezer at 0°F, a nicotine solution can remain viable and usable in excess of 2 years. 60mg Nicotine solution - 500ml
Notes on oxidation: Nicotine oxidizes rapidly with exposure to oxygen, light, heat, and moisture. As Nicotine oxidizes the color of the solution will turn yellow to amber brown in color. Higher strength Nicotine solutions will oxidize more rapidly than lower strength Nicotine solutions. This does not significantly diminish the strength, potency, or safe handling requirements of the solution. All of Wizard Lab's Nicotine solutions are purged with Argon gas at the time of bottling to eliminate excess oxygen, and help prevent oxidation during shipment. 60mg Nicotine solution - 500ml