Hydroalcoholic gels – Hand washing gelBefore moving on to the formula for a hydroalcoholic hand washing gel that we can easily prepare in pharmacy laboratories, let us briefly review the topic of gels.
Gels can be semisolid or solid in nature. For this purpose, gel-forming substances (gelatin, tragacanth, starch, and cellulose derivatives) are used. Aqueous gels are used for the scalp and on the skin in oil-free pharmaceutical preparations. Gels can be prepared with alcohol and oil or other anhydrous liquids. Some gels are solid and are prepared by cooling gelatin melted by heat. Some gels contain glycerin; these are used as wetting, softening, and protective agents.
They are transparent or opaque-looking semisolid preparations containing a gel-forming substance and a high proportion of solvent, in which the gelling agent forms a three-dimensional matrix structure.Lipophilic gels, contain liquid paraffin, polyethylene, or fatty acids gelled with colloidal silica, aluminum, or zinc soaps.Hydrophilic gels, gel with suitable agents such as starch, cellulose derivatives, carbomers, and magnesium-aluminum; they contain distilled water, glycerin, or propylene glycol.Classification of gels; gels are generally classified as single-phase or two-phase systems.a) Single-phase systemsSingle-phase systems are systems prepared with organic molecules completely dissolved in the liquid phase. Gels containing synthetic macromolecules (such as carbomers) or natural gums (such as gum tragacanth) are single-phase systems. They are widely used in pharmaceuticals and cosmetics due to their ease of application, use, and removal. Although water is mostly used as a solvent in single-phase systems, alcohol and mineral oil are also used. Gels prepared using water as a solvent are called hydrogels, while those containing alcohol or mineral oil are called organogels.b) Two-phase systemsTwo-phase systems are systems in which small inorganic molecules form a three-dimensional, non-rigid network structure within the liquid phase. Since inorganic molecules do not dissolve, they remain dispersed in the liquid. Aluminum hydroxide gel can be given as an example of these systems.
Gelling agents used in the pharmaceutical and cosmetic industries are expected to have the following properties:
. They must be inert and pure.
. They must be compatible with the active substance and excipients in the formulation.
. They should be used at low concentrations.
. They should be economically feasible and easily obtainable.
. Their rheological properties should not change significantly with temperature during use and storage.
. They must be cosmetically and aesthetically acceptable.Hand washing gel
Formula:
Rp.
Glycerin 4 g
Carbopol 0.19 g
Alcohol 66 g
Triethanolamine 0.1 g
Distilled water 28 g
Preparation of the formula:First, 28 grams of distilled water is added to a beaker. With a mechanical stirrer set to a speed of 180 rpm, 0.19 g of carbopol is added, and the speed of the mechanical stirrer is adjusted to 635 rpm to continue stirring for 15-20 minutes until a homogeneous appearance is obtained. Then, the stirrer speed is reduced to 180 rpm and 66 g of alcohol is added into the beaker. After 5 minutes, 0.1 g of triethanolamine is added. After 15 minutes, 4 g of glycerin is added to the mixture. After 10 minutes, the formula is completed by optionally adding an essence containing lemon, orange, or pomegranate.
Wishing you a good week…Source:1-Medical Formulary 11th Edition Prof. Dr. Kasım Cemal Güven
2-Ege University Publications. Practical Handbook of Pharmaceutical Technology 2nd Edition. Editor Prof. Dr. Özgen ÖZER
3-https://www.youtube.com/watch?v=eE5oC4eV-1Y
Specialist Pharmacist Ahmet Nezihi Pekcan
Pekcan Pharmacy – Konya
[email protected]
Tel: (332) 3520657http://www.majistralformul.com/
