Principles involved in Thickening• Stokess law - is the basis of the falling-sphereviscometer, in which the fluid is stationary in a verticalglass tube. A sphere descends through the liquid. itreaches terminal velocity, which can be measured by thetime it takes to pass two marks on the tube.• Thixiotropy - It is a property of certain gels which tendto flow on the account of stress applied on it.
Hair Styling Gel FormulationIngredient Weight % FunctionDeionized Water 61.2 DiluentPVP 2.5 Hair Settling ResinAminomethyl Propanol 0.30 Neutralizing AgentCARBOPOL 0.5 Rheology ModifierWheat Protein 0.5 ConditionerMethyl Paraben 0.5 PreservativeEthanol 34.5 Solvent
Hydroxy Ethyl Cellulose• It is derived from cellulose• It is a non-ionic water soluble Polymer• It can – 1) Thicken 2) Bind 3) Emulsify 4) Form Films 5) Retains Water
Salient Features Of H.E.C• Provides a smooth and silky feel to product• It has high ionic tolerance• It gives an extremely high clarity in gels• It offers good compatibility with surfactants• Wide range of viscosities can be achived withHEC
• A purified cellulose is treated with NaOH to form aswollen alkali cellulose• This swollen alkali cellulose is treated withethylene oxide to get a long chains of hydroxy ethylcellulose
Problems with HEC• CLOUDINESS tends to appear in clear solution ina short span of time• It gives a sticky feeling on the hand over a periodof time.• It consists of 5% of volitile matter which is notaccepted worldwide.
Toothpaste Formulation With HECIngredienta % weightGelling agent (HEC) 1Humectant(Glycerine) 10-30Abrasive(CaCO3) 15-40Sweetner(Saccharin) 0.1-0.2Flavour 1-1.5Surface active agent 1-2Presevative ,colour & Water qs