Question

You have an IM injection of Rocephin 2 GM per 10 ml vial. You put 1 ml in an empty vial and dilute with 3.3 ml of Lidocaine HCL 2% for injection. What is the final concentration of Rocephin in mg/ml?

A) 250 mg/ml
B) 400 mg/ml
C) 600 mg/ml
D) 800 mg/ml

Answer 1

The final concentration of Rocephin in mg/ml is approximately 46.51 mg/ml.

Step-by-step explanation:

The final concentration of Rocephin in mg/ml can be calculated using the dilution equation, M.V₁ = M₂V₂, where M₁ is the stock concentration of Rocephin, V₁ is the total volume of Rocephin added to the vial, M₂ is the final concentration of Rocephin in the vial, and V₂ is the total volume in the vial. In this case, the stock concentration of Rocephin is 2 GM per 10 ml vial, which is equivalent to 200 mg/ml. The total volume in the vial is 4.3 ml (1 ml of Rocephin solution + 3.3 ml of Lidocaine solution).

Using the dilution equation, we can calculate the final concentration as follows:

M₁ * V₁ = M₂ * V₂

200 mg/ml * 1 ml = M₂ * 4.3 ml

M₂ = (200 mg/ml * 1 ml) / 4.3 ml

M₂ ≈ 46.51 mg/ml

Therefore, the final concentration of Rocephin in mg/ml is approximately 46.51 mg/ml.