[HonestChemist]

A little clarification would be nice. At what scale are you making this? The difference between immersion blenders and Homogenizers is one of shear. Most immersion blenders use high speed to produce shear, but because this is typically done with a spinning blade shear levels are relatively low and dont work to well for scaling up. Homogenizers on the other hand don’t run quite as fast (typically 2000-5000 rpm) but they produce greater shear force by the fact that its a blade inside a cage that forces liquid through holes (kind of like putting your fist in the palm of your other hand and grinding. This action can force smaller particle sizes. This is also more scaleable as many homogenizers can be used “in-line” through a pump and hose that gets recirculated.

Also due to the fact that the “particle size” that is being referenced in these procedures most likely is describing oil droplet particle size for creating stable emulsions, you can estimate this size by using a simple 100x light microscope. These can be purchased for as little as $250 on Amazon.

If you are making small lab / hme batches an immersion blender should work fine. If you are paying a CMO to do the work ensure they have a homogenizer on hand.

[HonestChemist]

Just curious, did you perform any form of Challenge testing (PET)? Changing the packaging is a good step, but it would be better to have a reliably self preserving formula. Consumers can do a lot to a package and that liability is not worth skipping a PET. I have had formulas fail PET at a pH of above 10, its uncommon, but can happen.