Hi, I have prepared a drug solution that is dissolved in DMSO. We are giving IP injection to mice. The final stock concentration is 2mg/ml in 5% DMSO, 2% Tween-80 and 93% Saline.
Before injection, we leave out the drug at room temperature to thaw. In the beginning, the solution is clear and liquid however later it turns into opaques. I am attaching the photo for reference. I will appreciate it if you could help me out with this.
Thanks in advance
Every IV formulation needs het-saw experiments. Depending on your composition you may find out that you have precipitation. Check the physicochemical properties of your API and formulation excipients to find out why. Some surfactants have a cloud point in certain conditions.
Most likely, this drug is well soluble in DMSO but not that well soluble in water (saline). Therefore, you observe its partial or complete precipitation. Freezing and thawing might promote the compound's precipitation. For the IP injection, however, it might be still applicable (not always), but not for IV injections.