Grittiness is caused by undissolved or large-particle azelaic acid crystals suspended in the formula. The solution is micronization — reducing particle size below 10 microns — combined with a well-designed emulsion or gel matrix. Not all contract labs own the milling equipment required. On AJ Cosmo Labs, you can filter for chemists and manufacturers who explicitly list micronized active-ingredient processing as a capability.
Read the full guide on Azelaic acid formulations →