This document discusses the importance of tonicity and defines hypertonic, hypotonic, and isotonic solutions. It explains that tonicity is a measure of effective osmotic pressure between two solutions separated by a semi-permeable membrane. Hypertonic solutions have a higher concentration than body fluids and cause cells to shrink. Hypotonic solutions have a lower concentration than body fluids and cause cells to swell and burst. Isotonic solutions have the same concentration as body fluids and do not affect cell volume. The document provides examples of different concentration saline, dextrose, and lactated ringer's solutions and their classification as hypertonic, hypotonic or isotonic. It also discusses the importance of solutions being

1. N A M E : V I S H A K H A P R A V I N Y E N A R E
S U B : S T E R I L E P R O D U C T
IMPORTANCE OF
TONICITY

2.  Tonicity is a measure of the effective osmotic
pressure gradient; the water potential of
two solutions separated by a semi permeable cell
membrane. In other words, tonicity is the
relative concentration of solutes dissolved in
solution which determine the direction and
extent of diffusion. It is commonly used when
describing the response of cells immersed in an
external solution

3.  Osmotic pressure is defined as the
external pressure required to be applied so
that there is no net movement of solvent
across the membrane.

4. CLASSIFICATIONS OF TONICITY
Hypertonic
Hypotonic
 Isotonic.

5. HYPERTONIC SOLUTION
 Hyper: excessive
 A solution having higher osmotic
pressure than the body fluids
(0.9% Nacl) is known as
hypertonic solution.
 These solutions draw water from
the body tissues to dilute and
establish equilibrium.

6. ACTION OF HYPERTONIC SOLUTION
 For example, if 3% Nacl solution is added to blood,
osmotic pressure directs a net movement of water
out of the cell, causing it to shrink and wrinkled ,as
water leaves the cell.
 This movement is continued until the
concentrations of salt on both sides of the membrane
are identical.
 Hence, 3% Nacl solution is hypertonic with the blood

7. HYPERTONIC SOLUTIONS
 3% Saline
 5% Saline
 10% Dextrose in Water (D10W)
 5% Dextrose in 0.9% Saline
 5% Dextrose in 0.45% saline
 5% Dextrose in Lactated Ringer’s

8. HYPOTONIC SOLUTION
 Hypo: ”under/beneath”
 A solution with low osmotic
pressure than body fluids is
known as hypotonic solution
 The effects of administering a
hypotonic solution are generally
more severe than with hypertonic
solutions, since ruptured cells can
never be repaired.

9. ACTION OF HYPOTONIC SOLUTION
 Hypertonic solutions show the opposite effect when
compared to hypertonic solutions where the net
movement of water into the cell causes them to swell.
 In case of animal cells, they swell until they burst.
 If 0.2% Nacl solution is added to blood, the cells
swell and burst.
 Therefore, 0.2% Nacl solution is hypotonic with
respect to the blood.

10. HYPOTONIC SOLUTIONS
0.45% Saline (1/2 NS)
 0.225% Saline (1/4 NS)
0.33% saline (1/3 NS)

11.  Iso: same/equal
 Solutions that have the same
osmotic pressure as that of body
fluids are said to be isotonic
with the body fluid.
 Body fluids such as blood and
tears have osmotic pressure
corresponding to that of 0.9%
Nacl or dextrose aqueous
solution
 thus, a 0.9% Nacl or 5 %,
dextrose solution is called as
isosmotic or isotonic.
ISOTONIC SOLUTION

12. USES OF ISOTONIC SOLUTIONS
 to increase the EXTRACELLULAR fluid volume due
to blood loss,
 surgery,
 dehydration,
 fluid loss that has been loss extracellularly.

13. ISOTONIC FLUIDS
 0.9% Saline
 5% dextrose in water (D5W)
(also used as a hypotonic solution after it is
administered because the body absorbs the
dextrose BUT it is considered isotonic)
 5% Dextrose in 0.225% saline (D5W1/4NS)
Lactated Ringer’s

14. Difference Between Hypertonic Isotonic
And Hypotonic Solution

15. IMPORTANCE OF TONICITY
 It is important for a solution to be isotonic with a bodily
fluid to prevent irritation and cell damage, and to
maximise drug efficacy.
 If a hypotonic solution (with lower osmotic pressure than
that of a bodily fluid) is administered intravenously
water will pass into the red blood cells, causing them to
swell and possibly burst (haemolysis).
 If a hypertonic solution (with higher osmotic pressure
than that of a bodily fluid) is administered intravenously
then water is drawn from the cells in an attempt to dilute
the solution, causing them to shrink (crenation)

16. METHODS TO ADJUST TONICITY
 Cryoscopic method
 White-Vincent method
 Sodium chloride equivalent method
 Molecular concentration method