Isotonic solution and application in pharmacy slideshare

Isotonic solution and application in pharmacy presentation by Dr. asgharullah khan

1. Isotonic Solution & Their Application in PHARMACY Ref : Physical Pharmacy by Myrtin ., Chapter 09., Buffered and Isotonic Solutions., Page No 209 onward. & The Science and practice of pharmacy “ Remingtons ” Ed 21 st 17 th Chapter ., part 2, page no 250 onward.

2. Solution… A solution is a homogeneous mixture of two or more substances. One of the substances is called a solvent (a substance in which other substance or substances are dissolved). The substances dissolved in a solvent are called solutes . A solution can exist in a solid, liquid or gas form depending on mixed substances and external conditions such as temperature and pressure.

3. Parenteral Solutions Solutions to be applied to tissues or administered parenterally are liable, to cause irritation if their pH is greatley different from the normal pH of the relevant body fluid. Consequently the pharmacist must consider this point when formulating OPTHALMEIC SOLUTIONS, parenteral products and fluids to abraded surfaces. Tissue Irritation due to large pH differences b/w the solution being applied/administered will be minimal ; if the said Solution {to be applied} is ISOTONIC IN NATURE.

4. Buffered Isotonic Solution IN_VIVO_Buffer such as Blood., Lacrimal Fluids having capacity to manage pH of the relevant biological fluids.

5. TONICITY., Tonicity is a measure of the osmotic pressure (as defined by the water potential of the two solutions) of two solutions separated by a semipermeable membrane . It is commonly used when describing the response of cells immersed in an external solution. Like osmotic pressure, tonicity is influenced only by solutes that cannot cross the membrane, as only these exert an osmotic pressure. Solutes able to freely cross the membrane do not affect tonicity because they will always be in equal concentrations on both sides of the membrane. Osmotic pressure is the pressure that must be applied to a solution to prevent the inward flow of water across a semipermeable membrane.

6. Hypertonicity A hypertonic solution is a solution having a greater solute concentration than the cytosol . A hypertonic solution is used in osmotherapy [1] to treat cerebral hemorrhage . Hypotonicity A hypotonic solution is a solution having a lesser solute concentration than the cytosol . Isotonicity A condition or property of a solution in which its solute concentration is the same as the solute concentration as in CYTOSOL or another solution with which it is compared. .

7. Isotonic, hypertonic, hypotonic solutions Terms isotonic, hypertonic and hypotonic are usually used when a reference to cell of a living organizm is made, but it can be generally used to compare concentration of a solute in two solutions. Isotonic solutions Isotonic solutions are two solutions that have the same concentration of a solute. Hypertonic solution Hypertonic solution is one of two solutions that has a higher concentration of a solute. Hypotonic solution Hypotonic solution is one of two solutions that has a lower concentration of a solute.

8. ISOTONIC SOLUTION A solution that has no effect on the volume of tissues and cells. Thus, a cell, when placed in an isotonic solution tends neither to gain or lose water. Isotonic sports drinks have the same concentration as the body fluids.

9. 2% Boric Acid Solution ISOTONIC SOLUTION for Blood and EYE.. Red blood cell membrane is not impermeable to all drugs; that is, it is not a perfect semipermiable membrane. Thus, it will permit the passage of not only water molecules, but also solutes such as UREA., Ammonium Chloride., Alcohol and Boric Acid. A 2% BORIC ACID SOLUTION HAS SAME OSMOTIC PRESSURE AS THE BLOOD CELLS CONTENTS. Such solution called as ISOSOMATIC SOLUTION with Blood. The molecule of Boric acid can pass through the Erythrocyte membrane easily. It is interesting here that the mucous lining of the EYE acts as a true semipermiable membrane to boric acid in solution. 2% BORIC ACID SOLUTION SERVES AS AN ISOTONIC OPTHALMIC PREPRATION.

10. Isotonic solution Husa suggested that the term isotonic solution should be restricted to solutions having equal osmotic pressure w.r.t a particular membrane. Goyan and Reck introduced a new term as “ISOTONICITY VALUE” defined as concentration of an Aqueous sodium chloride solution having the same colligative properties as solution in question. 0.9g of NacL per 100 ml of solution needed not necessarily be isotonic with respect to the living membrane concerned. {Roughly Isotonic}

11. Example of ISOTONIC SOLUTION Normal saline solution (0.9% NaCl ) is considered isotonic with blood (although it actually has a slightly higher degree of osmolality). Ringers lactate is also considered isotonic. 5% Dextrose solution is also considered hypotonic compared with blood, because although it is isotonic while infusing, the dextrose is metabolized and free water is left, which is hypotonic.

12. ISOTONIC., Hyper Tonic and Hypotonic SOLUTION ISOTONIC SOLUTION(s) 0.9% NaCl (normal saline) isotonic Lactated Ringer's solution isotonic Hypo TONIC SOLUTION(s) 0.25% NaCl hypotonic 0.45% NaCl hypotonic 2.5% dextrose hypotonic D5W (acts as a hypotonic solution in body) Hyper TONIC SOLUTION(s) D5 NaCl hypertonic D5 in Lactated Ringer's hypertonic D5 0.45% NaCl hypertonic

13. Application of ISOTONIC SOLUTION Isotonic Fluid Volume Deficit Type of Loss : solute and water loss.,serum sodium level is decreased to 125-150 mEq /L. The cause of the fluid loss is GI fluid loss, urine loss and decreased oral intake. Clinical signs : poor skin; cold, dry dusky skin; sunken eyes; dry mucous membranes; rapid pulse; low B/P; irritability or lethargy Fluid Replacement Guidelines : Initially, a bolus of 0.9% sodium chloride or Ringer's lactate is given followed by 5% Dextrose in water and 0.45% sodium chloride. Half of the deficit should be replaced in the first 8 hours and the remaining half over the next 16 hours

14. Application Hypertonic Fluid Volume Deficit Type of Loss : There is greater water loss than solute loss. Volume moves from the ICF to the ECF. Sodium levels are maintained at over 150 mEq /L. The cause is GI fluid loss with hypertonic oral intake, diabetes insipidus , fever and hyperventilation. Clinical Signs : Include cold, thick and doughy skin; sunken eyes; a moderately rapid pulse; moderately low blood pressure; hyperirritability; high-pitched crying in babies; seizures. Fluid Replacement Guidelines: 5% Dextrose in water and 0.225% or 0.45% sodium chloride. If the patient is hypertensive Ringer's lactate should be given at a rate of 20mL/kg over one hour. Fluid replacement should be given slow and gradual over 48 hours. 2 to 3 mEq /kg of potassium should be given per 24 hours. At least 2 mEq /L/hour of sodium should also be included in the IV fluids that are used.

15. Undesirable effects of abnormal osmoticity .. Ophthalmic Medication Ophthalmic prep’s are intended for the administration into cul-de-sac of the eye must be isotonic to avoid any irritation. Abnormal tonicity of the CONTACT LENSE solutions can cause the lens to adhere to the eye and or cause burning or dryness/photophobia. Parenteral Medication Solution differ in Osmoticity /tonicity w.r.t serum may cause irritation_pain at the site of injection_Electrolyte Shifts., the severity depends upon the degree of variation from TONICITY.

16. To produce 300mg ISOTONIC SOLUTION of different drugs we need following ., ml of distilled H2O Alcohol  21.7 ml of H20 Ascorbic Acid 6.0 ml of H2o Boric Acid 16.7 ml of H2o Dextrose Anhydrous  6.0 ml of H2o Ephedrine Hcl  10.0 ml of H2o Glycerin  11.7 ml of H2o Penicillin G Na and K  6.0 ml of H2o Silver Nitrate  11.0 ml of H2o Zinc Chloride  20.3 ml of H2o

17. OSMOLALITY The term osmolality express the OSMOLAL Concentration. Emphasis on w/w relationship. Not influenced by temperature. A solution has an osmolal concentration of one when it contains 1 osmol of solute/kg of water.

18. OSMOLARITY The term osmolarity express the OSMOLAR Concentration. Emphasis on w/v relationship. influenced by temperature. A solution has an osmolar concentration of one when it contains 1 osmol of solute/liter of water. 0.9 % w/v solution of Nacl in water contains 9 gram of sodium chloride in 996.5 gram of wtaer equivalent to 0.309 osmolal value.

19. Methods to Adjust TONICITY and pH Class I Methods Cryoscopic Method Sodium Chloride Eq Method Freezing Point Depression Method Class II Methods White –Vincent Method The Sprowls Methods