Iv dilution

1. Drug
Dilutions &
Concentrations
Mansoura Faculty of medicine
Clinical Pharmacology Department
Dr Sameh AM Abdelghany

2. LOGO
 Drug Dilutions & Concentrations
It is important for patient safety that
you can :
I. Accurately calculate an appropriate
dose of drug for a given patient
II. Prepare an accurate dilution of a
given drug.

3. LOGO
 SI Units
 Definition:
o SI stands for Système Internationale and is
an alternative name for the metric system
of measurement.
o The main units are those used to measure :
1. Weight (kilogram, kg)
2. Volume (L or l)
3. Amount of substance (mole, mol).

4. LOGO
 Equivalences of weight & Volumes:
Equivalences of weight:
 1 kilogram (kg) = 1000 grams (g)
 1 gram (g) = 1000 milligrams (mg)
 1 milligram (mg) = 1000
micrograms (μg)
 1 microgram (μg) = 1000
nanograms (ng)
Equivalences of volume:
 1 litre (l) = 1000 millilitres (mL)
 1 millilitre = 1000 microlitre (μL)

5. LOGO
Drug concentrations, when
put as percentages (%),
either mean:
 Weight/weight (w/w %)
 Weight/volume (w/v %)
 Volume/volume (v/v %)
 Part/part %.

6. LOGO
 Concentrations:
 x % of a drug denotes x
grams of the drug (or solute)
in 100 milliliters of the
solution.
 eg. 1% lidocaine contains 1g
of lidocaine in 100 mL of
solution.

7. LOGO
 Dilutions:
 Anything represented in an
x:y (e.g. 1:1000) fashion, is
x grams of drug (or solute)
divided by y milliliters of
solution.
 e.g. 1:1000 of an epinephrine
solution contains 1g of
epinephrine in 1000 mL of
the solution.

8. LOGO

9. LOGO

10. LOGO
 Remember that 1 ml of water weighs 1 g
So…..
100% solution contains 100 g in
100 ml (or 1 g in 1 ml).
 This is the same as 1:1
solution.

11. LOGO
 Examples:
 10% soln. ≡ 10 g/100 ml soln.
(≡ 100 mg/ml) ≡ 1:10 soln.
 1% soln. ≡ 1 g/100 ml soln. (≡
10 mg/ml) ≡ 1:100 soln.
 0.1% soln. ≡ 0.1 g/100 ml soln.
(≡ 1 mg/ml) ≡ 1:1000 soln.
 0.01% soln. ≡ 0.01 g/100 ml
soln. (≡ 0.1 mg/ml) ≡ 1:10000
soln.

12. LOGO
Question: How many
milligrams of epinephrine are
present in 10 mL of a 1:1000
preparation?
Answer:
 1000 mL solution contain 1 g
(= 1000 mg) epinephrine.
 So, 10 mL will contain 10 mg
epinephrine.

13. LOGO
 Practice:
Express 0.5% (w/v) in mg/ml
oAnswer………………………..
Express 7.5% (w/v) in mg/ml
o Answer………………………..
Express 1:500 in mg/ml
o Answer………………………..
Express 1:2500 in μg/ml
o Answer………………………..

14. LOGO
 Question?
Hydrocortisone is available in
a vial of 100 mg in 2 mL. You
are to prepare 24 mL of a 5-
mg/mL hydrocortisone
dilution using the available
stock vials. How much
hydrocortisone (in milliliters)
and how much diluent (in
milliliters) will you need?

15. LOGO
 ANSWER:
 5 mg/mL = 0.005 g/mL, a 0.5%
solution
 100 mg/2 mL = 0.1 g/2 mL, a 5%
solution
Q1xC1=Q2xC2
X × 5(%) = 24 ml × 0.5(%)
So..
X= 2.4 ml hydrocortisone(answer1)
24ml -2.4ml = 21.6ml(answer2)

16. LOGO
Intravenous
Solutions

17. LOGO
Intravenous solutions
 The rate of flow of the IV solution
is monitored by maintaining the
proper number of drops per
minute varies with the caliber of
the IV set used
 should be carefully checked by
the nurse in each instance.
 Calibrations may vary from 10 to
60 drops / min.

18. LOGO
Calibrating the rate of intravenous
solution:
 IV bottles are supplied in 250, 500,
and 1000 mL sizes.
 The order may read for a specified
solution to be given at stated intervals
(e.g., 150 mL per hour for 8 hours), or
a specified amount may be
administered continuously (e.g., 500
mL is to run for a 6- hour period). In
every case the proper number of drops
per minute is determined by the
calibration of the particular IV set used.

19. LOGO

20. LOGO

21. LOGO
 Example 1:
 1000 mL of 5% dextrose in
water is ordered to be given
over an 8-hour period. The
equipment is calibrated so
that 15 drops = I mL. What
should be the rate of flow in
drops per minute?

22. LOGO
 First:
 determine the number of milliliters per
hour.
 Second:
 determine the number of milliliters per
minutes.
1000 mL
----------------- = 2.1 mL/min
8 hr x 60 min
 ANSWER:

23. LOGO
Third:
 Convert the milliliter per
minute to the drops
required.
 I mL = 15 drops
 Therefore, 2 ml = 30 drops
per minute.

24. LOGO
 Example 2:
 How long will it take for 250
ml of IV solution to be
delivered if it is flowing at 30
drops per minute? This set is
calibrated at 60-drops / ml.

25. LOGO
First:
 Convert drops to milliliters. If 60
drops = I mI, 30 drops = 0.5
mL/min.
Second:
 Determine how many minutes it will
take for this amount of fluid to be
absorbed.
250 mL
----------------- = 500 min
0.5 mL/ min
 ANSWER:

26. LOGO
Third:
 Convert minutes to hours:
500 min
------------- = 8.3 hr
60

27. C l i c k t o e d i t c o m p a n y s l o g a n .