title: Solid dispersions, part I: recent evolutions and future opportunities in manufacturing methods for dissolution rate enhancement of poorly water-soluble drugs.
abstract: BACKGROUND
  In recent years, the number of active pharmaceutical ingredients with high therapeutic impact, but very low water solubility, has increased significantly. Thus, a great challenge for pharmaceutical technology is to create new formulations and efficient drug-delivery systems to overcome these dissolution problems.
  
  
  METHODS
  Drug formulation in solid dispersions (SDs) is one of the most commonly used techniques for the dissolution rate enhancement of poorly water-soluble drugs. Generally, SDs can be defined as a dispersion of active ingredients in molecular, amorphous and/or microcrystalline forms into an inert carrier. This review covers literature which states that the dissolution enhancement of SDs is based on the fact that drugs in the nanoscale range, or in amorphous phase, dissolve faster and to a greater extent than micronized drug particles. This is in accordance to the Noyes-Whitney equation, while the wetting properties of the used polymer may also play an important role.
  
  
  CONCLUSIONS
  The main factors why SD-based pharmaceutical products on the market are steadily increasing over the last few years are: the recent progress in various methods used for the preparation of SDs, the effect of evolved interactions in physical state of the drug and formulation stability during storage, the characterization of the physical state of the drug and the mechanism of dissolution rate enhancement.
authors.affiliation: Aristotle University of Thessaloniki, Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Thessaloniki, Greece. dbic@chem.auth.gr
authors.forename: Dimitrios N
authors.initials: DN
authors.lastname: Bikiaris
mesh_terms: D000818:Animals; D001682:Biological Availability; D001702:Biopharmaceutics / Q000379:methods* / Q000639:trends; D002626:Chemistry, Pharmaceutical; D003505:Cyclodextrins / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D004355:Drug Stability; D006801:Humans; D049329:Nanostructures / Q000008:administration & dosage / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000737:chemistry*; D010599:Pharmacokinetics; D012995:Solubility; D013535:Suspensions
chemical_list: D003505:Cyclodextrins; D004337:Drug Carriers; D004364:Pharmaceutical Preparations; D013535:Suspensions