In: Advanced Math
A 25-year-old male presents to clinic complaining about eye pain and itching in his eyes. Upon examination the ophthalmologist found redness and some discharge of yellow pus. He looked into the retina to see if there were any abnormalities. He then cultured the pus and found a bacterial infection. He prescribed a fortified tobramycin ophthalmic solution of 0.5% w/v. The patient took the prescription to the pharmacist. The pharmacist looked at his shelves and found a tobramycin solution containing only 3 mg/mL concentration and a tobramycin injection containing 40 mg/mL. How many milliliters of this injection the pharmacist must add aseptically to a 5-mL container of the ophthalmic solution to prepare one 0.5% w/v in concentration
The quantity of the injection to be mixed with 5ml solution to obtain the desired concentration (5% w/v) is considered as "k". The procedure to find the k value is given in the picture..
Finally, the pharmacist has to add 0.2857ml of injection to 5ml of solution to make it 0.5% w/v concentration.