Making herbal capsules, can't figure the equation?

[Dremen]

Hello everyone. This will probably be easy for the members here, but I have a learning disability that makes numbers extremely hard for me so I ask your assistance please.

The formula below is to figure out the amount of filler powder to active substance ratio.

Desired mg of aspirin is 20mg not 100mg per capsule

Total weight of baking soda per cap=530mg
Total weight of aspirin per cap=430mg

Formula calls for 48 caps total, please substitute that for 100 caps. Thanks for help with this.




1. Load 24 empty caps into the capsule machine, then fill all 24 caps with Baking Soda (tamping powder if final caps will be tamped).
2. Empty all the Baking Soda out of the capsule machine and weigh it. Total weight = 17,160mg

3. Divide that weight (17,160mg) by the number of capsules (24) to get the total weight per cap. 17,160mg / 24 = 715mg a cap.

4. Repeat these steps with the Aspirin powder. Total weight = 11,760mg / 24 = 490mg a cap.

5. Now we need to figure out the ratio of Aspirin to Baking Soda.

100mg Aspirin = Unknown mg of Baking Soda

490mg Aspirin = 715mg Baking Soda

(100mg Aspirin x 715mg Baking Soda) / 490mg Aspirin = 146mg of Baking Soda (this is the Unknown mg of Baking Soda, and how much must be removed to make space for 100mg of Aspirin)

715mg Baking Soda - 146mg = 569mg Baking Soda (this is how much Baking Soda to use per cap)

569mg Baking Soda x 48 caps = 27,312mg Baking Soda

100mg Aspirin x 48 caps = 4800mg Aspirin

So to make 48 100mg Aspirin caps we need 4800mg of Aspirin powder and 27,312mg of Baking Soda.

 

[Dremen]

I'm getting per 100 caps:

50.5 grams baking soda filler
2 grams aspirin

This correct?

Thank you kindly ?

 

[JeffM]

You want each capsule to contain 20 mg of aspirin. And you want to make 100 capsules. So how much aspirin do you need? 100 * 20 = 2000 mg = 2 grams. Obvious, right?

Now step 4, which just repeats steps 1 through 3 but with aspirin, tells you how many milligrams of aspirin are in a single capsule, namely 490 mg. So if you fill a capsule with just 20 mg of aspirin, the capsule is [imath]1 - \dfrac{20}{490} = \dfrac{470}{490} \approx 95.92\%[/imath] empty.

Steps 1 through 3 indicates that 715 mg of baking soda fill a capsule. But you need to fill only 95.92% of a capsule.

[math]95.92\% * 715 = 685.828[/math] milligrams.

But you want a hundred capsules. 100 times 685.828 = 68582.8 mg or about 68.6 grams of baking soda.