number of hydrophilic groups in molecule nh value of hydrophilic groups in molecule Hh number of lipophilic groups in molecule nl value of lipophilic groups in molecule Hl In the case of fatty acid esters of polyvalent alcohols, HLB value can be determined by the following correlation: (15.) saponification number S number Aacid HLB can be also calculated with ethoxy number and alcohol groups: (16.) number of ethoxy groups E of alcohol groups in polyvalent alcohol Pnumber or with hydration heat: (17.) hydration heat Q The surface active materials can have natural or synthetic origin. According to their structure, ionic and ionic can be distinguished. Natural surface active materials may be: 1) hydrocarbon derivatives (e.g. acacia, tragacanth, agar-agar, pectin) 2) protein types (such as gelatin, casein), 3) high molecular weight alcohols (e.g. stearyl alcohol, cetyl alcohol, cholesterol), 4) other (pl.: lecithin). 5) The ionic surface active materials can be cation or anion type. 6) Dispersion process of results in negative charged ions in water. Soaps (e.g. type surface active materials sodium palmitate, sodium stearate, sodium oleate), alkyl sulfates, alkyl phosphates are categorized to this group. Sodium lauryl sulfate has especially very great moistening and strong solubilizing and cleaning effect, with high HLB. Fig. of anion type surface active substances (Sodium lauryl sulfate)
ionic nh number of hydrophilic groups in molecule Hh value of hydrophilic groups in molecule nl number of lipophilic groups in molecule Hl value of lipophilic groups in molecule In the case of fatty acid esters of polyvalent alcohols, HLB value can be determined by the following correlation: (15.) S saponification number Aacid number HLB can be also calculated with ethoxy number and alcohol groups: (16.) E number of ethoxy groups Pnumber of alcohol groups in polyvalent alcohol or with hydration heat: (17.) Q hydration heat The surface active materials can have natural or synthetic origin. According to their structure, ionic and can be distinguished. Natural surface active materials may be: 1) hydrocarbon derivatives (e.g. acacia, tragacanth, agar-agar, pectin) 2) protein types (such as gelatin, casein), 3) high molecular weight alcohols (e.g. stearyl alcohol, cetyl alcohol, cholesterol), 4) other (pl.: lecithin). 5) The ionic surface active materials can be cation or anion type. 6) Dispersion process of type surface active materials results in negative charged ions in water. Soaps (e.g. sodium palmitate, sodium stearate, sodium oleate), alkyl sulfates, alkyl phosphates are categorized to this group. Sodium lauryl sulfate has especially very great moistening and strong solubilizing and cleaning effect, with high HLB. Fig. of anion type surface active substances (Sodium lauryl sulfate)
2011-0016_01_the_theory_and_practise_of_pharmaceutical_technology.docx