I had some older l-dex in a blue bottle in 2007 that was in a thicker solution. As product dried around the threads of the lid, the residue was thick and goody. Current [new] product is in a thinner watery solution that creates a hard deposit around the threads like sugar would.
I have had problems with the newer product. My E2 labs acted like I was only getting ½ of the expected dose. I ended up using around twice as much of the product as I would expect to achieve E2=22pg/ml. Still newer product still also needs larger amounts than expected.
I have a 3watt LED penlight flashlight. I held that against the bottom of the blue bottle in a closet ? dim ambient light. The bottle had large snow flake like crystals that settle to the bottom of the bottle. That explains the low dosing.
I heated water in the microwave and set the bottle in that, tipped up on one corner so the bottom was heating as well. [Warming product in the microwave might destroy the anastrozole?] With shaking, rewarming water? I was able to dissolve the product. I took my then normal dose of close to .75ml [EOD]. I really have felt that dose! Too much.
Two days later, I get the flashlight and now there are larger crystals, now more square than flakes and stuck hard to the bottom of the bottle. There really is a problem! So I warmed and dissolved everything again and took a smaller dose this time. —Update: Crystals were seen regrowing 4-5 hours afterwards.
I like the blue dropper bottles and do not throw the empties away. I rinse them out and store them with the lids off to dry. I got the flash light out to look at those. They all have crystals stuck to the bottom of the bottles. That means the dispensed product is under-dosed, including some, perhaps to a lesser degree with the product from 2007.
Some work needs to be done to find a vehicle that can carry 1mg/ml without dumping crystals. Ethyl alcohol would work well and vodka is known to work as well. But perhaps not ideal for other reasons.
LMW PEG might be a good solvent. Glycerin also could be evaluated. Propylene glycol might also be of interest. All are food safe and used in pharmaceuticals. It would not be difficult to do a solubility test for these.
If the anastrozole dissolves at room temperature, then precipitation over time is probably not a concern. Once that is known, heat can be used during processing to speed things up.
A mix with some ethyl alcohol might have some advantages as well. Alcohol might facilitate introducing the adex power into one of the other thicker organic solvents.