- Refrigerated (2-8°C) unopened RU-58841 solution is expected to last around 12 months.
- Opened solution is best used within 3 to 6 months.
- Sealed powder stored dry and dark at room temperature is stable for 2 or more years.
- Room-temperature storage should stay below 25°C and out of direct light.
- RU-58841 is photosensitive, so Norwood Labs supplies the 5% solution in amber UV-attenuating glass.
- At 50 mg/mL RU-58841 sits near its solubility limit and can crystallise in the cold, which reverses with gentle warming.
- Keep it cool, dark, and sealed. Fridge is better than room temperature; amber glass is better than clear.
- Solution: ~12 months unopened refrigerated, 3-6 months once opened.
- Powder: 2+ years sealed and dark. Freezer extends it further.
- UV light is the single biggest enemy. Never store on a windowsill.
Why storage matters for RU58841
Store RU58841 solution refrigerated at 2-8°C in amber glass, away from light; unopened it is expected to last around 12 months, and opened solution is best used within 3 to 6 months. Sealed powder kept dry, dark and below 25°C is stable for 2 or more years. The variables that matter, in order, are UV light, temperature and oxygen exposure.
Storing RU58841 solution
Norwood Labs supplies RU58841 5% solution in amber UV-glass with a graduated dropper for exactly this reason. Amber glass attenuates UV and short-wavelength visible light, which is where photodegradation happens. The label instruction is short: cool, out of direct sunlight, cap sealed between uses.
- Fridge (2-8°C): recommended for stock you plan to keep more than a month. Extends shelf life to around 12 months unopened.
- Room temperature (below 25°C): fine for the bottle in daily rotation. Keep it in a drawer or cabinet, not on a shelf in direct light.
- Freezer: further extends life. Allow to thaw fully before use and mix gently.
Storing RU58841 powder
Powder is inherently more stable than solution because there is no solvent for slow hydrolysis to work on. Norwood Labs powder ships in a sealed, resealable foil pouch. Keep it that way.
- Room temperature, dry, dark: 2+ years is realistic for sealed powder.
- Refrigeration or freezing extends it further and is worth it if you are storing more than you will use in the near term.
- Do not decant into a clear jar. Do not leave it open on a bench.
Signs of degradation
In solution, visible signs include a colour change (fresh RU58841 solution is very pale to colourless; deep amber or brown is a warning sign), a strong solvent smell that was not there before, or visible precipitate that does not redissolve with gentle mixing. Powder should stay pale off-white; noticeable darkening is a sign it has been exposed to light, heat, or air.
Buying with the right container to start
Storage only matters if the packaging is right in the first place. Every Norwood Labs solution ships in amber UV-glass with a UV-attenuating cap and a graduated glass dropper. Every powder ships in a sealed, light-proof foil pouch. Published sample reports are available.