AN INVESTIGATION OF THE PARAMETERS INFLUENCING THE BIOADHESIVE PROPERTIES OF MYVEROL 18-99 WATER GELS/

An in vitro assessment was undertaken of the parameters influencing th e bioadhesive strength of lyotropic liquid crystalline gels formed by the monoglyceride blend Myverol 18-99 and water. The gels were found t o bind more strongly to a dry Perspex surface than to moist mucosal ti ssue and were shown to be weaker bioadhesives than Carbopol 934P and s odium alginate. The works of adhesion and forces of detachment were in dependent of contact time, were reduced by the presence of surface wat er and increased with an increase in the compression force, suggesting that interpenetration was not the mechanism of bioadhesion. The bioad hesion of Myverol 18-99/water gels appeared to be due to secondary che mical bonds, such as van der Waals forces, but was limited by their co hesive strength. An in vivo gel retention assessment by gamma scintigr aphy showed that the gels were retained within the vaginal cavity for a period of at least 6 h. (C) 1996 Elsevier Science Limited