Hello Sir Can you do some pharma calculations questions. I found one question in a book. But explanation not given so I am unable to solve it. Ques is.. Vol of distbn of drug is 500 ml and Target concn of drug in blood is 5g/L. 20 % of administered drug is reached to systemic circulation . What will be the loading dose of drug? A) 1 gm B) 5 gm C)12.5 gm D) 25 gm. Answer given is 12.5 gm. Please give a reply for the explanation 🙏