Copied from another board. An excellent guide
This is how I do it. No 2 people probably do it the same. First off, there is 1000mcg's in a mg. There are 1000mg in a gram. Can you guess how many grams in a kilo, lol.
The powder that is the main compound of desire is called active ingredient. The powder used to fill up space is called filler. I will be referring to both compounds combined as active ingredient as well.
I will use a powder similar in density as the active ingredient for the filler. You want both powders to be as close to the same weight and grain size.
Weigh an empty capsule. For the lesson I will use made up weights so don't use these weights. You'll need to go through the motions and weigh out everything yourself. All powders will be different. We'll use 100mg for empty weight. Fill cap with filler. I pick my capsule machine up about 2 inches and drop over and over again to get powder to sift down. We'll call this sift down. So fill with filler and sift down over and over until it doesn't sift down anymore. Now let's say you get a weight of 600mg. Take away the empty weight (100mg) from full weight (600mg) and you have a total weight of 500mg of total powder. Now, subtract the amount of desired active ingredient you want (per capsule) from the total powder and that will make room for your active ingredient in the total powder space. Let's say you want 50mg per capsule. That would be 50mg from 500mg for a total of 50mg active ingredient and 450mg filler. If you want 100 capsules you'll multiply both numbers by 100. So for active ingredient you'll have 5 grams and for filler you'll have 45 grams. Weigh out your filler and put in bowl to the side. Weigh out your active ingredient and place in large mixing bowl. Take an equal amount of filler to that of product in the mixing bowl and mix. I use a very thin card and I slip underneath the product and flip/fold it over itself over and over again. Maybe 4 or 5 times. Then I rotate the bowl a quarter turn and repeat. I may do this about 4 times. Then add a similar amount of filler to the active ingredient again and repeat. Just eyeball the amounts added. You don't have to be exact. Do that until all filer is added. I only do 100 caps at a time. This method will give you a very consistent product. Just my opinion, though that if you try and do too much at a time that it won't be consistent hence the 100 caps at a time. Add your capsules to the capping machine and begin to add product and sift until product won't sift any more. Pretty much it right there. My cap machine makes 50 caps at a time so you'll have enough powder for 2 turns.