A study of the spread surface of polymeric dispersions of Eudragit.
The rheology of non-Newtonian fluid systems is complex. Their experimental study is difficult because of the existence of many dependent variables. In the present work, a mathematical equation is proposed to calculate the spread surface from a simple viscosimetric study in a theoretical way. It was determined for multiple parameters. The spread surface has to be marked because of its direct relation to the shear stress; this fact enabled us to connect one variable dependent on the compression deformation with another dependent on the shear deformation. At the same time, the viscoelastic phenomenon can be evidenced by applying this mathematical equation.
Lucero
M J
MJ
Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Sevilla, Spain.
Garcia-Andreu
J
J
Roman
F
F
Leon
M J
MJ
D000180:Acrylic Resins; D007785:Lactose / Q000031:analogs & derivatives*; D008747:Methylcellulose / Q000031:analogs & derivatives*; D008962:Models, Theoretical; D010078:Oxazines; D011108:Polymers; D011109:Polymethacrylic Acids; D012212:Rheology; D013314:Stress, Mechanical
D000180:Acrylic Resins; D010078:Oxazines; D011108:Polymers; D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer; D008747:Methylcellulose; C071191:MK 458; D007785:Lactose