HPLC Solution preparation for any tablets analysis

How we can prepare same concentration solution of pure dry standard of any drug
compare to its formulated tablet (like Diclofenac Tablet 5mg) in HPLC analysis?
eg. Diclofenac Standard and Diclofenac Tablet 5mg

so how we can prepare standard solution to compare with 5 mg tablet

and please explain same for the any liquid injection