Pharmaceutical Calculations

CALCULATORS NOT PERMITTED FACULTY OF SCIENCE AND ENGINEERING SCHOOL OF PHARMACY EXAMINATION PAPER _____________________________________________________________ Module Code: 4PY019 Module title: Pharmacy Stage 1 Examination title: Pharmaceutical Calculations Date: May 2022 Year lead: Michelle Elston Examiner: Olivia Mina Time Allowed: 1 hour ______________________________________________________________ Instructions to candidates: This is a closed book examination, which consists of 20 ‘fill in the box’ questions to be completed in 1 hour. Print your student number clearly in the space provided at the bottom of this page. Attempt ALL questions. The pass mark is determined by cut-scoring and there is no negative marking. Write your final answer in the ‘Answer’ section at the bottom of each question, using the pre-printed answer grid. Your final answer must be written in the answer grid using a pencil. If you wish to change an answer, rub out your first solution carefully, taking care not to smudge across the boxes, then re-write your answer clearly. The decimal point is already placed on the answer grid. When completing the answer grid use the pre-entered decimal point to guide you. For example, if the answer is 118 tablets, fill in the answer as shown below. For whole numbers, do not enter zeros after the decimal point. Decimal points are provided. If the answer contains a decimal point, use the decimal point that is pre-entered. For example, if the answer to a question is 450.5 g, fill in the answer as shown below. Do not use commas. For example, if the answer is four hundred and thirty thousand units, write this as 430 000 as shown below. However, if the answer is less than 1, then enter a ‘leading’ zero, e.g. write 0.15 mL as shown below It is an examination requirement that you show a logical working out process to arrive at a computed answer. Accordingly, even where a submitted answer is correct, it will not be awarded a mark in the absence of a logical working out method with supporting numerical data. Read the questions carefully, and ensure that all answers are expressed in the units specified in the answer box Student number: ................................... 1 Question 1 Express 0.053g in micrograms Answer micrograms Question 2 Express 0.456L (litres) in ml (millilitres) Answer mL Question 3 How many milligrams of potassium permanganate are required to prepare 625ml of a 1 in 10,000 solution? Give your answer to one decimal place. Answer mg 2 Question 4 An antibiotic is given to a baby at a dose of 150 micrograms/kg every 8 hours. The infant weighs 6kg. How many milligrams of the antibiotic will the baby have received after a 7day course? Give your answer to one decimal place. Answer mg Question 5 A bottle of eye drops contains drug B at a concentration of 0.2 %w/v. It is available in bottles containing 2.5 ml. How many milligrams of drug B does each bottle contain? Answer mg Question 6 An injection is available as a 1 in 1000 solution. The standard child’s dose is 0.3mg. How many millilitres of the injection will contain a standard child’s dose? Give your answer to one decimal place. Answer mL 3 Question 7 A patient weighing 60kg requires drug E at a total daily dosage of 60mg/kg given in three divided doses. Drug E is available as 300mg capsules. How many capsule(s) will provide one dose? Answer capsule(s) Question 8 You receive a prescription for a 4-year-old child for a pain-relieving medicine. The patient has been prescribed a dose of 250mg to be given four times a day for a total of 7 days. The medicine is available as an oral liquid containing 20mg/ml. How many millilitres of the oral liquid would you need to dispense to complete the prescription? Answer mL Question 9 Drug C is available as a 1 in 100 solution. If the relative molecular mass is 25, what is the molar concentration of [M] (expressed in moles/litre) of this solution. Give your answer to one decimal place. Answer M (moles/L) 4 Question 10 Drug L is available as capsules each containing 25 micrograms of the active pharmaceutical ingredient. A patient is prescribed 0.125mg of drug L as a daily dose. How many capsule(s) of drug L should be dispensed for 28 days’ treatment? Answer capsule(s) Question 11 What is the resulting concentration of a glucose solution (expressed as % w/v) if 60 ml of 30 % w/v glucose is mixed with 140 ml of 10 % w/v glucose? Answer % w/v Question 12 A stock solution of disinfectant is available as 20 % w/v, which is diluted before use. How many millilitres of water are required to prepare 2L of a 1 in 500 solution of the disinfectant? Answer mL 5 Question 13 A patient has been started on a new medication by the General Practitioner. The starting dose is 250mg three times a day for one week, followed by 250mg twice a day for one week and then the patient will continue on the dose of 250mg once a day for a further two weeks and then stop. The tablets are available as 250mg. How many tablet(s) should be dispensed for the first 4 weeks of treatment? Answer tablet(s) Question 14 How many grams of active pharmaceutical ingredient (API) are required to produce 5kg of cream containing 25 % w/w API? Answer g Question 15 How many millimoles of sodium bicarbonate (NaHCO3) are present in 200ml of oral solution containing 4.2 % w/v? [ Ar Na = 23, H = 1, C= 12, O=16] Answer mmol 6 Question 16 A doctor orders 120g of an ointment containing 0.4 %w/w active pharmaceutical ingredient which can be prepared by diluting an ointment containing 2.4 % w/w API with a suitable diluent. How many grams of the 2.4 %w/w ointment would be needed to prepare the product the doctor ordered? Answer g Question 17 You are preparing sodium bicarbonate eye drops by dissolving 500mg of sodium bicarbonate in water, which you make up to final volume of 5ml. What is the concentration (expressed as %w/v) of the resulting solution? Answer %w/v Question 18 Drug G (which can be diluted with water) is available as 10 %w/v stock solution. A prescription is received for 120ml of a solution of drug G containing 100mg/5ml. How many millilitres of the stock solution should you dilute to prepare this prescription? Answer mL 7 Question 19 A drug is prescribed at a dose of 30mg/kg/day given in divided doses. On admission to hospital, Ms M is taking three 300mg capsules three times a day. If the dose is correct, what is Ms M’s weight in kilograms? Answer kg Question 20 A patient is prescribed nasal drops with directions to use 3 drops in both nostrils every twelve hours for 5 days, then reducing to 2 drops in both nostrils twice a day for 10 days and then stop. 1ml of the nasal drop solution produces 20 drops. A bottle contains 5ml of solution. How many bottle(s) are required for this course of treatment? Answer bottle(s) 8