Reconstitution of Solutions Chapter 12

2 Parts of Solutions

3 Reconstitution Drug

4 Parenteral Solution from a Solid Solute Solvent or diluent 4.8 mL sterile water Solid solute Zithromax 500 mg 5 mL reconstituted solution Zithromax 100 mg per mL

5 Reconstitution Label for Zithromax 1/10/xx, 0800, reconstituted as 100 mg per mL Expires 1/17/xx, Keep refrigerated. G.D.P.

6 Parenteral Solution Reconstitution Procedure Order: Kefzol 225 mg IM every 6 hours

7 Parenteral Reconstitution Procedure Inject 2 mL air into sterile water diluent vial Withdraw 2 mL sterile water Add 2 mL sterile water to Kefzol 500 mg powder Make Kefzol 500 mg in 2.2 mL reconstituted solution for Kefzol 225 mg/mL Withdraw 1 mL Kefzol solution for dosage of 225 mg

8 Multiple-Strength Reconstitution Drug

9 Different IM and IV Reconstitution Instructions

10 Reconstitution Drug Order Order: Solu-Medrol 200 mg IV every 6 hours

11 Reconstitution Drug Order Supply: –500 mg vial of powdered Solu-Medrol for IM or IV injection –Directions on left side of label

12 Reconstitution Drug Order Each 8 mL contains –“Reconstitute with 8 mL Bacteriostatic Water for Injection with Benzyl Alcohol –Methylprednisolone sodium succinate equivalent to 500 mg methylprednisolone (62.5 mg per mL)”

13 Reconstitution Dosage Calculation What do we know? –First, to fill the order, how much and what type of diluent must you add? –Directions state to add 8 mL of bacteriostatic water for injection with benzyl alcohol.

14 Reconstitution Dosage Calculation What do we know? –Second, what is supply dosage of reconstituted Solu-Medrol? –When adding 8 mL of diluent, the supply dosage is 62.5 mg per mL

15 Reconstitution Dosage Calculation What do we know? –Third, what is resulting total volume of this reconstituted solution? –Total volume is 8 mL –You know this because 62.5 mg per mL × 8 mL = 500 mg

16 Reconstitution Dosage Calculation What do we know? –Finally, how many full doses of Solu-Medrol are available in this vial? –Vial contains 500 mg and order is for 200 mg –There are two full doses in the vial –Reconstitution label is needed

17 Reconstitution Dosage Calculation Now you have a vial of 500 mg of Solu- Medrol –Add 8 mL of diluent Final yield of the solution is 62.5 mg per mL, your supply dosage. Calculate one dose

18 Reconstitution Dosage Calculation Step 1. Convert –No conversion is necessary –Order: Solu-Medrol 200 mg IV every 6 hours –Supply: 62.5 mg per mL

19 Reconstitution Dosage Calculation Step 2. Think –You want to give more than 1 mL –You want to give more than three times 1 mL

20 Reconstitution Dosage Calculation Step 3. Calculate Given intravenously every 6 hours

21 Solution Strength A fraction expresses strength of a solution made from a liquid concentrate: –Numerator is number of parts of solute –Denominator is number of parts of solution –Difference between denominator (final solution) and numerator (parts of solute) is number of parts of solvent

22 Solution Strength Example: strength nutritional formula –1 part concentrate –3 parts of total solution –3 - 1 = 2 parts solvent (water)

23 Calculating Solutions To prepare solutions: –Apply ratio-proportion to find amount –Quantity of desired solution Amount of liquid solute = Amount of solvent

24 Solution Calculation Example: –A physician orders a patient’s wound irrigated with strength hydrogen peroxide and normal saline solution every 4 hours while awake.

25 Solution Calculation 60 mL per irrigation for 3 irrigations during your 12 hour shift –Prepare 60 mL × 3 irrigations = 180 mL total solution How much stock hydrogen peroxide and normal saline will you need?

26 Solution Calculation Step 1. Convert –No conversion is necessary

27 Solution Calculation Step 2. Think –You want to make strength 2 parts solute (concentrated hydrogen peroxide) to 3 total parts solution Amount of solvent is 3 – 2 = 1 part saline For 180 mL of solution, you will need of it as solute (120 mL) and of it as solvent (60 mL)

28 Solution Calculation Step 3. Calculate (solute) (solution)