Surfactants and its importance

General Description of Surfactants, its classification , its effects, structure of surfactants

1. Importance of Surfactants PRESENTED BY GUIDANCE BY Danish Sayyad SANDHAN MADAM FIRST YEAR M.PHARM Roll no - 09 QUALITY ASSURANCE TECHNIQUES 1 NDMVP SAMAJ’S COLLEGE OF PHARMACY, NASHIK

2. Surfactants and Its Importance

3. Definitions Surface Tension the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.

4. Surfactants (Surface Active Agents) Surfactants are materials that lowers the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Also can be termed as Amphiphiles as it contains both hydrophilic and hydrophobic regions.

5. Effect of Surfactant .

6. Structure of Surfactant Surfactant have Amphipathic Structure. H ead Tail Tail Or Hydrophobic Group. Little affinity for bulk solvent. Usually hydrocarbon chain in aqueous solvent, can be linear of branched Head or hydrophilic Group. Strong Affinity for bulk solvent, can be neutral or charged.

7. Classification of Surfactants S urfactants are classified according to polar head group. A non-ionic surfactant has no charged groups in its head. The head of an ionic surfactant carries a net positive, or negative charge. If the charge is negative, the surfactant is more specifically called anionic; if the charge is positive, it is called cationic. If a surfactant contains a head with two oppositely charged groups, it is termed zwitterionic . Non Ionic Anionic Cationic zwitterionic

8. 1.) Non Ionic Surfactants Nonionic surfactants have covalently bonded oxygen-containing hydrophilic groups, which are bonded to hydrophobic parent structures. Water Soluble. Solubility decreases with increase in temperature.

9. Examples of Non Ionic Surfactants

10. 2.) Anionic Surfactants Anionic surfactants contain anionic functional groups at their head, such as sulfate, sulfonate , phosphate and carboxylate. 1.) Suphate , Sulphonate and Phosphate Esters :- Prominent sulfates include ammonium lauryl sulphate , Sodium lauryl sulphate (sodium dodecyl sulfate, SLS, or SDS). Docusate ( dioctyl sodium sulfosuccinate ) Perfluorooctanesuphonate (PFOS) Perfluorobutanesuphonate Alkyl-aryl ether phosphates Alkyl ether phosphates 2.) Carboxylates These are the most common surfactants and comprise the carboxylate salts (soaps), such as Sodium Sterate . More specialized species include Sodium Lauroyl Sarcosinate and carboxylate-based fluorosurfactants such as Perfluorononanoate , Perfluorooctanoate (PFOA or PFO).

11. 3.) Cationic Surfactants Polar Hear is Positively Charged Examples :- 1.) pH-dependent primary, secondary, or tertiary amines. 2.) Permanently charged quaternary ammonium salts : Cetrimonium Bromide (CTAB ) Cetylpyridinium chloride (CPC) Benzalkonium chloride (BAC) Benzethonium chloride (BZT) Dimethyldioctadecylammonium chloride Dioctadecyldimethylammonium bromide (DODAB)

12. 4.) Zwitterionic ( Amphiphilic ) Surfactants S urfactants have both cationic and anionic centers attached to the same molecule The cationic part is based on primary, secondary, or tertiary amines or quaternary ammonium cations . The anionic part can be more variable and include sulfonates . Examples :- CHAPS 3-[(3- ch olamidopropyl) dimethyl a mmonio ]-1- p ropane s ulfonate The most common biological zwitterionic surfactants have a phosphate anion with an amine or ammonium, such as the phospholipids, phosphatidylserine , phosphatidylethanolamine , phosphatidylcholine , and sphingomyelins . Structure of CHAPS

13. Properties of Surfactants Critical Micelle Concentration (CMC) Hydrophile Lipophile Balance (HLB)

14. Critical Micelle Concentration Increasing concentration of surfactant in water slowly forming a layer on the surface and eventually forming micelles at or above the CMC. CMC is the concentration of surfactants above which micelles form and all additional surfactants added to the system go to micelles.

15. HLB Scale It is the measure of the degree to which the molecule is hydrophilic or lipophilic The HLB value can be used to predict the surfactant properties of a molecule: < 10 : Lipid-soluble (water-insoluble) > 10 : Water-soluble (lipid-insoluble) 1 to 3: anti-foaming agent 3 to 6: W/O (water in oil) emulsifier 7 to 9: wetting and spreading agent 13 to 16: detergent 8 to 16: O/W (oil in water) emulsifier 16 to 18: solubiliser or hydrotrope

16. Importance of Surfactants QUATs as Anti Microbials Quaternary ammonium compounds have also been shown to have antimicrobial activity. Certain quaternary ammonium compounds, especially those containing long alkyl chains, are used as antimicrobials and disinfectants. Kills the Germs by Disrupting Cell Membranes. Examples benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, cetalkonium chloride etc. As a Wetting Agent A surfactant that, when dissolved in water, lowers the advancing contact angle, aids in displacing an air phase at the surface, and replaces it with a liquid phase Eg . 1.) the displacement of air from the surface of sulfur, charcoal, and other powders for the purpose of dispersing these drugs in liquid vehicles

17. 2.) the displacement of dirt and debris by the use of detergents in the washing of wounds; and the application of medicinal lotions and sprays to surface of skin and mucous membranes. The cleaning action of soaps and detergents is termed as detergency Detergency The cleaning action of soaps and detergents is termed as detergency. Lung/Pulmonary Surfactant Pulmonary surfactant is a mixture of lipids and proteins which is secreted by the epithelial type II cells into the alveolar space. Its main function is to reduce the surface tension at the air/liquid interface in the Lung and keep them from collapsing when an individual exhales. One of the most important pharmaceutical pulmonary surfactants is Survanta ( beractant ) As an Emulsifier A Substance which Stabilizes a Emulsion. Eg . Acacia , Polysorbate 20, 40, 60, 80, Lecithin etc.

18. Foaming and Antifoaming Agents. Foaming is useful in case of antimicrobial formulation and also in Cosmetics such as Shaving Creams, Face wash, Shampoo, Conditioners etc. Anti Foaming Agents include Alcohol , Ether , Castor Oil used to break the Foam. Bio-Surfactants Defined as the surface-active biomolecules produced by microorganisms with wide-range of applications. Increasing mobility, increasing solubility, lubrication, wetting , rewetting, softening, fixing dyes, making emulsions, stabilizing dispersions, coagulating suspended solids, making foams, preventing foam formation and defoaming . The most significant application of biosurfactants was studied in bioremediation for example in removing heavy metals from soils.

19. Paints Ink Toothpaste Hair Conditioners Sanitizers Other Applications

20. References 1.) Martins, Physical Pharmacy and Pharmaceutical Science ,Sixth Edition, Lipincott Williams & Wilkins, 2011, Pg no 355-382 2.)M.E Alton, The Science of Dosage From Design, Second Edition, Churchill Livingstone, Pg no. 54-69 3.) Wikipedia- The free Encyclopedia.