Lotions: Definition, Applications, and Preparation PDF

Lotions Definition: - liquid preparations contain solid materials for application externally to the skin, for the treatment of local conditions, e.g. inflammation, acne “ acne biotec” , infection (bacterial, fungal “trosyd”, viral and parasitic). Also for use as wash, gargles, and solutions for uret...

Lotions Definition: - liquid preparations contain solid materials for application externally to the skin, for the treatment of local conditions, e.g. inflammation, acne “ acne biotec” , infection (bacterial, fungal “trosyd”, viral and parasitic). Also for use as wash, gargles, and solutions for urethral or vaginal irrigation. -the majority of lotions are suspensions or emulsions, as result of this they should carry on their labels (shake the bottle before use & for external use only). In addition to the therapeutic agent(s), may contain: ◼ Alcohol: this acts as a coolant (due to evaporation following application) and as a co-solvent. ◼ Humectants: these act to retain moisture on the skin after application. The most commonly used example is glycerol. ◼ Vehicle: lotions are aqueous formulations and therefore will contain purified water. ◼ Preservatives: as ◼ phenol (0.2–0.5%), chlorocresol (0.075–0.12%) , benzoic acid (0.1–0.3%). ◼ Components to stabilize the suspended therapeutic agent. *applications of lotions:- 1- Medicinal lotions:- Antiseptic and germicidal and in treatment of skin diseases and as cooling and mild anesthetic application for skin irritation. 2-cosmetic lotions:- Applied to hair, scalp, face and hands, and most widely used as sunblock preparations. * Sunlight is composed of visible light, IR and UV radiation - Infra-red rays produce a sensation of heat -UV radiations are responsible for therapeutic and toxic effects on the skin. -UV may penetrate the skin causing degeneration histidine is liberated which is converted TO histamine which causes:- 1- Dilatation of blood vessels. 2-induction of local irritation with severe itching burning And so, excessive exposure to UV leads to excessive biosynthesis of melanin bodies in the skin to act as protector against UV radiation *Notes* 1- Inclusion of alcohol in a lotion hastens its drying and increases its cooling effect, whereas inclusion of glycerol keeps the skin moist (hygroscopic). 2- Highly viscous, gummy suspending agents as gum tragacanth are not ideal for lotions due to their sticky nature. 3- For hydrophobic substances such as (sulphur, Mg. stearate), a wetting agent should be added to aid in wetting of the solid with the water such as glycerin or mineral oil.  Preparation of lotions Calamine lotion R/ Calamine 8 g. Zinc oxide 8 g. Glycerin 6 ml. water to 100 ml. Fiat lotion, mitte 20 ml. Sig.: M.D.U Calculations:- The required volume is 20 ml. then by dividing the whole amounts by 5 Calamine 1.6 g. Zinc oxide 1.6 g. Glycerin 1.2 ml. water or (lime water) to 20 ml. Make lotion, send 20 ml. Sig.: to be used as directed Label:- For external use only. To be shaken just before use. *procedure* - mix calamine and zinc oxide together in a mortar. - levigate with the required amount of glycerol. - add 10 ml. of lime water & levigate again. - transfer to a measuring device, then complete to the required volume. * Uses: - soothing and protective in case of skin irritation & diaper rash and dermatitis. Role of ingredients:- Calamine & zinc oxide:- -demulcent, soothing agent, used topically in dermatitis, skin rash, sunscreen preparations as a UV scattering agents. 2- Glycerol: - a- to keep the skin surface moist for a considerable time. b- to aid in wetting of calamine powder. c- To increase the viscosity of the lotion, decrease the sediment.