solubilization ( physical pharmacy )

presentation on solubilization

1. Solubilization NAME : SAMER AZIZ ROLL NO : DE-068 SUBJECT : PHYSICAL PHARMACY

2. SOLUBILIZATION: It can be defined as the preparation of a thermodynamically stable isotropic solution of a substance normally insoluble or very slightly soluble in a given solvent by the addition of component or by any suitable methods DEFINITION:

3. SOLUBILITY: DEFINITION: The maximum amount of solute that can be dissolve in a given amount of solvent

4. FACTORS THAT EFFECT SOLUBILIZATION: NATURE OF SOLUTE AND SOLVENT: The amount of solute that dissolves depends on what type of solute it is. While only 1 gram of lead (II) chloride can be dissolved in 100 grams of water at room temperature, 200 grams of zinc chloride can be dissolved. This means that a greater amount of zinc chloride can be dissolved in the same amount of water than lead II chloride

5. TEMPERATURE: Generally in many cases solubility increases with the rise in temperature and decreases with the fall of temperature but it is not necessary in all cases. However we must follow two behaviors: In endothermic process solubility increases with the increase in temperature and vice versa EXAMPLE: solubility of potassium nitrate increases with the increase in temperature In exothermic process solubility decrease with the increase in temperature. EXAMPLE: solubility of calcium oxide decreases with the increase in temperature Gases are more soluble in cold solvent than in hot solvent. PRESSURE: For solid and liquid solutes, changes in pressure have practically no effect on solubility For gaseous solutes, an increase in pressure increases solubility and a decrease in pressure decreases solubility

6. PARTICLE SIZE: Solubility will increase with the decrease size of solute particle because of the additional surface energy. This effect is generally small unless particles become very small typically smaller than 1 micro meter

7. SURFACTANTS: DEFINITION: Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants

8. TYPES OF SURFACTANTS: ANINOTROPIC : It contain anionic functional group at their head, that gives it the hydrophilic part, such as sulfate, sulfonate, phosphate and carboxylates Anionic surfactants are ionic and are made up of two ions positively charged, usually metal, ion and a negatively charged organic ion NON IONICTROPIC : It`s hydrophilic part carries no charge. They derive their polarity from having an oxygen–rich portion of the molecule at one end and a large organic molecule at the other end. The oxygen component is usually derived from short polymers of ethylene oxide or propylene oxide such as alcohol ethoxylates, polyoxyethylene alcohols, and ethylene oxide/propylene oxide

9. CATIONIC: These are positively charged molecules usually derived from nitrogen compounds. They are not commonly used as cleaning agents in hard-surface cleaners because of the tendency of the cationic positively charged molecule to be attracted to hard surfaces (that usually have a net negative charge). Many cationic surfactants have sanitizing properties that are useful in creating disinfectants that leave a cationic disinfectant film on the surface AMPHOTERIC: Those surfactants that change their charge with pH. They can be anionic, nonionic, or cationic depending on pH. Usually, any one amphoteric can be any two of the three charge states

10. PROPERTIES OF SURFACTANTS: They enable the cleaning solution to fully wet the surface being cleaned so that dirt can be readily loosened and removed . They clean greasy, oily, particulate-based, protein-based, and carbohydrate-based stains. They are instrumental in removing dirt and in keeping them emulsified, suspended, and dispersed so they don't settle back onto the surface being cleaned Surfactants are one of the major components of cleaning products and can be regarded as the 'workhorses': they do the basic work of breaking up stains and keeping the dirt in the water solution to prevent re-deposition of the dirt onto the surface from which it has just been removed. Surfactants disperse dirt that normally does not dissolve in water. Oil and water do not mix unless shaken vigorously in the bottle. They separate almost immediately afterwards. The same is true when washing your dishes or clothes. With the addition of surfactants, oil, which normally does not dissolve in water, becomes dispersible and can be removed with the wash water

11. MICELLES: DEFINITION: When surfactant are added to water, they self-assemble into little sphere called micelles with the hydrophilic head facing out and hydrophobic tail pointing in

12. TYPES OF MICELLES: SPHERICAL MICELLES: The micelles which are arranged in spherical form are called spherical micelles

13. ROD SHAPE MICELLES: The micelles which are arranged in rod form are called rod shaped micelles LAMELLAR MICELLES: The micelles which are arranged in plates (lamellae) form are called lamellar micelles

14. FORMATION OF MICELLE: Micelles form when the polar head and the non polar tails arrange in a special way. They are usually driven to arrange either with the polar heads out (oil in water) or with the polar head in (water in oil). Micelles only form when the concentration of surfactant is greater than the critical micelle concentration (CMC). The surfactant is any surface active material that can part the surface upon entering. The CMC is the concentration above surfactant when micelles will form spontaneously. The higher the concentration, the more micelles there are. Micelle formation also depend on the Krafft temperature. This temperature is when surfactants will form micelles. If the temperature is below the Krafft temperature, then there is no spontaneous formation of micelles. As the temperature increases, the surfactant will turn into a soluble form and be able to form micelles from a crystalline state. The hydrophobic effect is also a driving force that needs to be taken into account. This effect is characterized by the fact that like to form intermolecular aggregates in aqueous substances and in intramolecular molecules. Micelle formation can be summed up by thermodynamics, driven by entropy and enthalpy