Introduction and Types of Solution (1).pptx

pharm D students guide

1. PHYSICO -CHEMICAL PRINCIPLES

2. SOLUTION & SOLUBILIZATION

3. LEARNING OBJECTIVES After completion of this lecture, the student should be able to: Define solution Understand the various types of pharmaceutical solutions. Define solubility, saturated & unsaturated solutions Explain the importance of studying the phenomenon of solubility Define Solubility and miscibility

4. Definitions: Solution: is a homogeneous mixture composed of only one phase. The components are referred to the solute & the solvent . Solute: is the dissolved agent (less abundant part of the solution). Solvent : is the component in which the solute is to be dissolved (more abundant part of the solution).

5. Characteristics A solution is a homogeneous mixture . The particles of solute in a solution cannot be seen by naked eye ( micrometer/nanometer) A solution is stable, s o that the solute particles will not be settle down upon time. The solute (s) from a solution cannot be separated by filtration . It is composed only one phase . A true solution does not scatter light.

6. APPLICATIONS Preparation of pharmaceutical formulations Rapid onset of action Avoid Absorption/ bioavailability Solutions are used as reagents for analytical purposes.

7. ON THE BASIS OF NATURE OF SOLVENT Aqueous Solutions (contains water as solvent) Non-Aqueous Solutions (any solvent other than water) TYPES OF SOLUTION

8. On the basis of physical appearance 1. Gaseous solutions If the solvent and the solute are gases then called gaseous solutions. G ases are dissolved under a given set of conditions . Example: Air is a solution of gasses (oxygen & other gases in nitrogen).

9. Gas in Liquid solutions If the sol ute is gas and the solvent is liquid . E.g. oxygen in water Carbon dioxide in water Liquid in liquid solutions If the solvent and solute both are liquid. E.g. Alcohol in water, glycerin in water 2. LIQUID SOLUTIONS

10. SOLID IN LIQUID: When solute is solid and solvent is liquid. Example: Salt solution, Sucrose solution Body solutions CONTINUE…

11. Gas in SOLID: If gas is solute and solid is solvent. E.g : Hydrogen gas in metal B. Liquid in SOLID: If liquid is solute and solute is solid E.g. : Hexane in paraffin wax C. Solid in SOLID: if both solute and solvent are solid physically e.g. polymers containing plasticizer, alloys 3. SOLID SOLUTION

12. Co n t……

13. CONCENTRATED SOLUTION: the solution contains more solute than solvent. Example: Concentrated Iodine solution DILUTE SOLUTIONS: less portion of solution is occupied by solute. Example: Aromatic water like camphor water(2% of solute) ON THE BASIS OF STRENGTH

14. Types of Solutions Unsaturated Solutions – Solutions that have ability to dissolve more solute. Saturated Solutions – Solutions that have already dissolved maximum of solute at a particular temperature. Any more added solute would be settle d at the bottom without dissolv ing it . Supersaturated Solutions - Solutions that contain even more dissolved solute than saturated solutions . Solubilization is aided by heat.

15. Solub i lity R efers to the ability of a substance specifically, the solute to be dissolved in the solvent. In a quantitative way: it is the concentration of solute in a saturated solution at a certain temperature. In a qualitative way: it is the spontaneous interaction of two - or more substances (solute & solvent) to form a homogeneous molecular dispersion.

16. SOLUBILITY AND MISCIBILITY B oth terms used to refer the ability of one substance to dissolve in another substance. The solubility or miscibility of the solute is dependent on the kind of solute and solvent . The term miscibility refers to the ability of a liquid solute to dissolve in a liquid solvent .

17. Miscible substances are liquids that will dissolve in each other.

18. Importance of studying the phenomenon of solubility Understanding the phenomenon of solubility helps the pharmacist to: Select the best solvent for a drug or a mixture of drugs. Overcome problems arising during preparation of pharmaceutical solutions. Have information about the structure and intermolecular forces of the drug .