How to dispose of expired unused HPMC capsules at home?

We always store some commonly used drugs, such as vitamin C tablets, aspirin and vitamin B12. When these drugs are found to have expired, how should we deal with them? Ensure that these capsules do not cause harm to our environment and people's health.
Detailed steps:
Remove the original container and mix it with the unattractive substance.
We know that the capsules produced by HPMC are very healthy and soluble in water. There is no need to separate the shell and the filler.
Put the mixture in an airtight container. Throw the container into a non-recyclable trash can. Flush into the toilet.
Check the US Food and Drug Administration (FDA) list of drugs that can be flushed.
In order to avoid waste, we have also listed the following tips for retrieving expired capsule drugs.
Vitamin C can improve the pH of the soil and make plant leaves green.
How to make:
Put vitamin C tablets into warm water and mix with water plants in a ratio of 1:100. Aspirin can promote the regeneration of plant roots.
Grind aspirin and mix it with water in a ratio of 1:500-1000. Pruning the branches and soaking them in aspirin water for 20 minutes can increase the survival rate of cuttings.
Vitamin B12 can prevent plant rot. How to do:
Add a table to 2 bottles of mineral water and mix into a vitamin B12 solution. Cut off all the rotten roots and soak in the solution for more than half an hour. Vitamin B12 can make plants grow new roots as soon as possible.
Don't throw away the expired medicine, you can use it.