title: Moisture uptake of polyoxyethylene glycol glycerides used as matrices for drug delivery: kinetic modelling and practical implications.
abstract: OBJECTIVE
  Gelucire 50/13, a polyoxyethylene glycol glyceride mixture, has been widely used in drug delivery, but its moisture uptake behaviour is still poorly understood. In this study, the effects of relative humidity, temperature, and drug incorporation on the moisture uptake of Gelucire are reported in relation to their practical implications for preparation of solid dispersions using this material.
  
  
  METHODS
  DVS combined with kinetics modelling was used as the main experimental method to study the moisture uptake behaviour of Gelucire. Thermal and microscopic methods were employed to investigate the effect of moisture uptake on the physical properties of the material and drug loaded solid dispersions.
  
  
  RESULTS
  The moisture uptake by Gelucire 50/13 is temperature and relative humidity dependent. At low temperatures and low relative humidities, moisture sorption follows a GAB model. The model fitting indicated that at high relative humidities the sorption is a complex process, potentially involving PEG being dissolved and the PEG solution acting as solvent to dissolve other components.
  
  
  CONCLUSIONS
  Careful control of the storage and processing environmental conditions are required when using Gelucire 50/13. The incorporation of model drugs not only influences the moisture uptake capacity of Gelucire 50/13 but also the solidification behaviour.
authors.affiliation: School of Pharmacy, University of East Anglia, Norwich, NR4 7TJ, UK. sheng.qi@uea.ac.uk
authors.forename: Sheng
authors.initials: S
authors.lastname: Qi
authors.forename: Peter
authors.initials: P
authors.lastname: Belton
authors.forename: William
authors.initials: W
authors.lastname: McAuley
authors.forename: Doroty
authors.initials: D
authors.lastname: Codoni
authors.forename: Neerav
authors.initials: N
authors.lastname: Darji
mesh_terms: D004337:Drug Carriers / Q000737:chemistry*; D005079:Excipients / Q000737:chemistry; D005223:Fats / Q000737:chemistry*; D005989:Glycerides / Q000737:chemistry*; D006813:Humidity; D007700:Kinetics; D008956:Models, Chemical; D009821:Oils / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D005079:Excipients; D005223:Fats; D005989:Glycerides; D009821:Oils; D014867:Water; C071184:Gelucire 50-13; D011092:Polyethylene Glycols