Microparticles of polyvinyl alcohol for nasal delivery. I. Generation by spray-drying and spray-desolvation.

Spray-drying and spray-desolvation are described for the generation of polyvinyl alcohol microparticles intended for nasal administration. The spray-dried microparticles of polyvinyl alcohol were of an appropriate size distribution but consisted of hollow spheres, which made them unsuitable for nasal delivery, as rapid clearance and a varied deposition pattern would be expected. Microparticles were also produced by spraying polyvinyl alcohol (average molecular weight of 14,000) solution (12.5%, w/v) at 0.332 ml/min onto the surface of acetone (spray-desolvation). These microparticles were solid collapsed spheres with the desired size for nasal deposition (10-200 microns). This method can be applied to encapsulation of drugs that are heat labile such as peptides and proteins.