title: Solidification of nanosuspensions for the production of solid oral dosage forms and inhalable dry powders.
abstract: BACKGROUND
  Nanosuspensions combine the advantages of nanotherapeutics (e.g. increased dissolution rate and saturation solubility) with ease of commercialisation. Transformation of nanosuspensions to solid oral and inhalable dosage forms minimises the physical instability associated with their liquid state, enhances patient compliance and enables targeted oral and pulmonary drug delivery.
  
  
  METHODS
  This review outlines solidification methods for nanosuspensions. It includes spray and freeze drying as the most widely used techniques. Fluidised-bed coating, granulation and pelletisation are also discussed as they yield nanocrystalline formulations with more straightforward downstream processing to tablets or capsules. Spray-freeze drying, aerosol flow reactor and printing of nanosuspensions are also presented as promising alternative solidification techniques. Results regarding the solid state, in vitro dissolution and/or aerosolisation efficiency of the nanocrystalline formulations are given and combined with available in vivo data. Focus is placed on the redispersibility of the solid nanocrystalline formulations, which is a prerequisite for their clinical application.
  
  
  CONCLUSIONS
  A few solidified nanocrystalline products are already on the market and many more are in development. Oral and inhalable nanoparticle formulations are expected to have great potential especially in the areas of personalised medicine and delivery of high drug doses (e.g. antibiotics) to the lungs, respectively.
authors.affiliation: a Department of Pharmaceutics , UCL School of Pharmacy , London , UK.
authors.forename: Maria
authors.initials: M
authors.lastname: Malamatari
authors.affiliation: a Department of Pharmaceutics , UCL School of Pharmacy , London , UK.
authors.forename: Satyanarayana
authors.initials: S
authors.lastname: Somavarapu
authors.affiliation: a Department of Pharmaceutics , UCL School of Pharmacy , London , UK.
authors.forename: Kevin M G
authors.initials: KM
authors.lastname: Taylor
authors.affiliation: a Department of Pharmaceutics , UCL School of Pharmacy , London , UK.
authors.forename: Graham
authors.initials: G
authors.lastname: Buckton
mesh_terms: D000280:Administration, Inhalation; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D058995:Dry Powder Inhalers; D005079:Excipients / Q000737:chemistry; D005612:Freeze Drying; D053758:Nanoparticles; D012995:Solubility; D013607:Tablets
chemical_list: D005079:Excipients; D013607:Tablets
keywords: dry powder for inhalation; matrix former; nanosuspension; redispersibility; solid oral dosage forms; solidification