title: Study of the structure of coherent emulsions.
abstract: The object of the study was to analyse relationship between the rheological properties, thermogravimetric behaviour, physical stability, and the wetting contact angle of the lipophilic and aqueous phase of 300 creams of different compositions with a high water content (60-80%, w/w). The starting point was Junginger's theory: water is found in the cream structure in energetic (interlamellar) and steric forms (bulk water). Based on our investigations, an exponential function was found to exist between the contact angle of wetting and the slope of the TG-curves, between the contact angle of wetting and the viscosity of the creams, and between the contact angle of wetting and the evaporation rate of water. A linear relationship was found between the contact angle of wetting and the quantity of water separable by centrifugation.
authors.affiliation: Department of Pharmaceutical Technology, University of Szeged, Szeged Eötvös u. 6, H-6720, Szeged, Hungary. eros@pharma.szote.u-szeged.hu
authors.forename: István
authors.initials: I
authors.lastname: Eros
authors.forename: Magdolna
authors.initials: M
authors.lastname: Kónya
authors.forename: Ildikó
authors.initials: I
authors.lastname: Csóka
mesh_terms: D004355:Drug Stability; D004655:Emulsions / Q000737:chemistry*; D005079:Excipients / Q000737:chemistry; D009824:Ointments / Q000737:chemistry; D012212:Rheology; D013818:Thermogravimetry; D014783:Viscosity; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: D004655:Emulsions; D005079:Excipients; D009824:Ointments; D014867:Water