Vijay Agarwal* and Meenakshi Bajpai Pages 1 - 15 ( 15 )
Background: Poor solubility and low dissolution rate limit the work at poorly water-soluble drugs like Esomeprazole. To overcome this problem, different technologies had to be used but could not resolve the problem, significantly. The main aim of this study was to prepare the nanocrystals using evaporative precipitation ultrasonication method in order to improve the dissolution rate and stability of Esomeprazole (ESM).
Methods: For getting the nanocrystals, different nanoformulations were prepared using the pluronic F-68 in different concentration, and then screened formulation was lyophilized in presence of two distinct cryoprotectants; mannitol and sucrose. The obtained nanocrystals were characterized for their re-dispersibility, crystalline state, dissolution behavior, particle size, polydispersibility index and morphology. Dissolution study of ESM nanocrystals was performed in buffer solution of pH-7.4, and compare to that of bulk ESM sample and ESM/pluronic F-68 physical mixture.
Results: Cryoprotectant containing nanocrystals exhibit the re-dispersion in water after the manual shaking. 5% mannitol containing nanocrystals showed the least polydispersity index (0.42 ± 0.11) and narrowest particle size (186 ± 12.9 nm). The powder x-ray diffraction (PXRD) pattern and differential scanning calorimeter (DSC) thermograms revealed that crystalline state of drug was not changed after the different physical treatment. Freeze-dried nanocrystals showed a faster dissolution rate and almost 99.45% of drug was released within 60 min. However, the bulk drug and a physical mixture of bulk drug/pluronic F-68 showed only 22.65% and 21.3% of drug release, respectively, after 60 min.
Conclusion: The different findings revealed that nanocrystals could be a potential alternate for solving the dissolution rate and stability issue of ESM like poorly soluble drugs.
Nanocrystal, dissolution, esomeprazole, freeze drying, ultrasonication, stability
Rajkumar Goel Institute of Technology (Pharmacy), 5-Km. Stone, Delhi-Meerut Road, Ghaziabad (U.P.), Institute of pharmaceutical research, G.L.A. University, Mathura-Delhi Road, Mathura (U.P.)