Polyvinyl alcohol is used primarily in topical pharmaceutical and
ophthalmic formulations. It is used as a stabilizing
agent for emulsions (0.25–3.0% w/v). Polyvinyl alcohol is also used
as a viscosity-increasing agent for viscous formulations such as
ophthalmic products. It is used in artificial tears and contact lens
solutions for lubrication purposes, in sustained-release formulations
for oral administration, and in transdermal patches. Polyvinyl
alcohol may be made into microspheres when mixed with a
glutaraldehyde solution.Polyvinyl alcohol is a tough, whitish polymerthat can be formed into strong films, tubes, andfibers that are highly resistant to hydrocarbonsolvents. Although polyvinyl alcohol is one ofthe few water-soluble polymers, it can be renderedinsoluble in water by drawing or by theuse of cross-linking agents.