Water dispersible microbicidal cellulose acetate phthalate film

CAP and hydroxypropyl cellulose (HPC) were dissolved in different organic solvent mixtures, poured into dishes, and the solvents evaporated. Graded quantities of a resulting selected film were mixed for 5 min at 37°C with HIV-1, HSV and other STD pathogens, respectively. Residual infectivity of the treated viruses and bacteria was determined.The prerequisites for producing CAP films which are soft, flexible and dispersible in water, resulting in smooth gels, are combining CAP with HPC (other cellulose derivatives are unsuitable), and casting from organic solvent mixtures containing ≈50 to ≈65% ethanol (EtOH). The films are ≈100 μ thick and have a textured surface with alternating protrusions and depressions revealed by scanning electron microscopy. The films, before complete conversion into a gel, rapidly inactivated HIV-1 and HSV and reduced the infectivity of non-viral STD pathogens >1,000-fold.Soft pliable CAP-HPC composite films can be generated by casting from organic solvent mixtures containing EtOH. The films rapidly reduce the infectivity of several STD pathogens, including HIV-1. They are converted into gels and thus do not have to be removed following application and use. In addition to their potential as topical microbicides, the films have promise for mucosal delivery of pharmaceuticals other than CAP.Polymers, used in the past as pharmaceutical excipients and in drug delivery, are increasingly being considered for specific therapeutic and prophylactic applications [1-5]. They appear promising for topical applications as microbicides to prevent infection by sexually transmitted disease (STD) pathogens, including the human immunodeficiency virus (HIV-1) [6]. One of these promising polymeric microbicides is cellulose acetate phthalate (CAP) [7-14]. CAP has been used for enteric film coating of tablets and capsules [15] and thus has a well-established safety record for human use. CAP is not soluble in water at pH <≈5.8. For this reason, it must be used in a