This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacokinetics, Subject name: Pharmacology
False about sustained release tablets - 
Select and explain. 
A. Release drug at a constant rate, B. Less chances of toxicity, C. Contain large amount of drug, D. Margin of safety is an important consideration
B: Less chances of toxicity
Answer: B: Less chances of toxicity 
Explanation: Ans. is 'b' i.e., Less chances of toxicity o A sustained-release dosage form provides an initial amount of drug sufficient to produce a desired therapeutic plasma concentration and continuously releases the drug at a constant (zero-order) rate which will maintain the therapeutic concentration for an extended period (recommended dosage interval). The margin of safety of the drug (active ingredient) is an important consideration in the selection of a candidate drug, because sustained-release products contain a large amount of the drug and the possibility of 'dosedumping' with resultant toxicity exists.