title: Development of pH sensitive polymeric nanoparticles of erythromycin stearate.
abstract: BACKGROUND
  Bioavailability of conventional tablet of erythromycin stearate is low as it is unstable at acidic pH and also shows a low dissolution rate.
  
  
  OBJECTIVE
  It was proposed to protect it from the acidic condition of the stomach along with an increase in dissolution rate by formulating pH sensitive nanoparticles.
  
  
  METHODS
  The nanoparticles were prepared by the solvent evaporation technique using different quantities of Eudragit L100-55 and polyvinyl alcohol (PVA). Size reduction was achieved by high speed homogenization technique using Digital Ultra Turrax homogenizer. The formulation was optimized using 3(2) factorial design, keeping drug polymer ratio and surfactant concentration as independent variables. Particle size, entrapment efficiency, and drug-release (DR) were studied as dependent variables.
  
  
  RESULTS
  Optimized batch containing 1:0.3 erythromycin stearate: Eudragit L100-55 ratio and 1.0% PVA showed 8.24 ± 0.71% DR in pH 1.2 in 1-h and 90.38 ± 5.97% in pH 5.5 and pH 6.8 within 2-h, respectively.
  
  
  CONCLUSIONS
  The optimized batch exhibited lower release in acidic pH and faster release in higher pH compared to the marketed preparation.
  
  
  CONCLUSIONS
  Thus the present study concludes that pH sensitive nanoparticles of erythromycin stearate increases the dissolution of the drug in intestinal pH and also protect it from acidic pH, which may help in improving the bioavailability of erythromycin.
authors.affiliation: Department of Pharmaceutics, Parul Institute of Pharmacy, Vadodara, Gujarat, India.
authors.forename: Sulekha
authors.initials: S
authors.lastname: Bhadra
authors.affiliation: Department of Pharmaceutics, Parul Institute of Pharmacy, Vadodara, Gujarat, India.
authors.forename: Atin B
authors.initials: AB
authors.lastname: Prajapati
authors.affiliation: Formulation Development, Ipca Laboratories Limited, Mumbai, Maharashtra, India.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Bhadra
keywords: Eudragit; factorial design; high-shear; optimization; polyvinyl alcohol