Download Colloids and it's properties ,colloidal dispersion and more Assignments Pharmacy in PDF only on Docsity! Colloids and their role in Pharmaceutical Industry Colloids A mixture in which very small particles of one substance are distributed evenly throughout another substance. Examples of colloidal systems from daily life « ) e- Foarss nk Fou, anche: Detergents el ae PO eH Classification There two criteria's for classification of are ¢o| Rasdd.on the state of Aggregation of phase 2. Based on the interaction of phase Aggregation of phase > Based on the state of aggregation of dispersed phase and dispersion medium, colloidal solutions are classified into 1. Aerosol (liquid or solid in gas) 2. Foam (gas in liquid) 3. Emulsion (liquid in liquid) 4. Sol (solid in liquid) 5. Gel (liquid in solid) Interaction of phase ”On the basis of affinity between two phases, colloidal solutions are classified into 1. Lyophobic Lyophilie 1 i protecting sols Examples particles sols of Metals, sulphur 2. Lyophilic sols Examples gums, etarch Kinetic properties > Brownian motion > Rapid, random, zigzag movement of colloidal particles through dispersion medium. > This movement is due to bombardment of colloidal particles by the molecules of dispersion medium. Optical properties > Tyndall Effect > Light scattering by colloidal particles. > Bright cone of scattered light is called Tyndall cone. Electrical properties > Charges on colloidal particles: the colloidal solution would be unstable. > It may be positively or negatively charged. > Due to acidic and basic groups Eye lotions > There are various eye lotions that are prepared by colloidal solutions. > Argyrol and protargyrol Colloidal sulphur > It is used as disinfectants. > It is a homeopathic remedy used to treat skin conditions such as psoriasis, eczema etc. Colloidal copper > It is used in treatment of cancer. > It is used as a remedy for burns, arthritis, parasites, viral and bacterial infections. Colloidal electrolytes Increase solubility, stability and taste of compounds > Used as additives in drugs > E.g. Quaternary Ammonium salts colloidal Silica > Prevents flocculation. » Stability to drugs. > e.g. silicon dioxide Natural colloids > Plasma protein. > Gelatin coating over tablets and granules. > For protection.
