Final answer:
Tablets and capsules must dissolve before the drug is available for absorption, which affects the onset of the drug's effects.
Step-by-step explanation:
The question is asking about the onset of drug availability for absorption when using tablets and capsules. Tablets and capsules must dissolve before the drug can be absorbed into the body. This means that the onset, or the time it takes for the drug to become available for absorption, is determined by how quickly the tablet or capsule dissolves. For example, when a drug is administered intravenously, it enters the bloodstream immediately, resulting in a quicker onset. However, when drugs are administered orally or intramuscularly in tablet or capsule form, it takes longer for the drug to dissolve and reach its peak concentration in the bloodstream, thus prolonging the onset.