importance of Tonicity

tonicity

1. NAME : VISHAKHA PRAVIN YENARE SUB: STERILE PRODUCT 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

17. THANK YOU