title: Co-precipitation with PVP and Agar to Improve Physicomechanical Properties of Ibuprofen.
abstract: Objective(s) : Ibuprofen is a problematic drug in tableting due to its viscoelastic properties. Additionally its high cohesivity results in low flowability. In this study, co-precipitation of ibuprofen with varying concentration of agar and PVP to optimize properties of Ibuprofen was carried out.
  
  
  METHODS
  Co-precipitates of ibuprofen- PVP or agar were prepared by solvent evaporation technique under vacuum condition. Differential scanning calorimetry (DSC), X -ray diffraction of powder (XRDP) and FT-IR spectroscopy were used to investigate the solid state characteristics of the co-precipitates. The dissolution behavior, flowability, particle size and compaction properties of various batches were also studied.
  
  
  RESULTS
  Co-precipitation of drug with agar led to a change in habit from needle to plate shape crystals, while drug -PVP co-precipitates had agglomerated structure and consisted of numerous crystals which had been aggregated together. The co-precipitates showed improved flow properties compared with ibuprofen alone. Precipitation of ibuprofen with these additives led to modification in the dissolution of the drug. Agar in 1% w/w improved slightly the dissolution rate of drug while PVP had a negative impact and led to reduction in the dissolution rate of drug to less than that of pure drug. The all obtained co-precipitates exhibited significantly improved tableting behavior compared with drug crystals alone. This may be due to this fact that, the polymer covering the drug particles increases and changes the nature of the surface area available for interparticulate bonds between particles. DSC, XRDP and FT-IR experiments showed that drug particles, in co-precipitates samples, did not undergo polymorphic modifications.
  
  
  CONCLUSIONS
  The study highlights the influence of polymeric additives on crystallization process leading to modified performance.
authors.affiliation: Drug applied Research Centre and School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Maghsoodi
authors.forename: Farhad
authors.initials: F
authors.lastname: Kiafar
keywords: Agar; Co-precipitation; Crystallization; Ibuprofen; PVP