The basic objectives of this study were to prepare and characterize solid dispersions of poorly water-soluble drug etoricoxib using lipid carriers by spray drying technique. The properties of solid dispersions were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), differential scanning calorimetry (DSC), hot-stage microscopy (HSM), radiograph powder diffraction (XRPD), and dissolution studies. The absence of etoricoxib peaks in XRPD profiles of solid dispersions suggests the transformation of crystalline etoricoxib into an amorphous form. In the HSM examination of solid dispersions, the dissolution of drug in the lipid carriers was observed, which was also confirmed by the absence of etoricoxib peak in DSC curves of solid dispersions. The DRIFTS spectra revealed the presence of hydrogen bonding in solid dispersions. The in vitro dissolution test showed a significant increase in the dissolution rate of solid dispersions as compared with pure etoricoxib, spray-dried etoricoxib, and physical mixtures of drug with lipid carriers. Therefore, the dissolution rate of poorly water-soluble drug etoricoxib can be significantly enhanced by the preparation of solid dispersions using lipid carriers by spray drying technique.
Gelucire can stabilize AET and improve its biopharmaceutical performance at a low excipient/drug ratio and may provide a better alternative to conventional stabilizers such as PVP.
The purpose of this research was to investigate the potential use of anionic κ-carrageenan and nonionic hydroxypropylmethylcellulose (HPMC, K4) to improve the matrix integrity of directly compressed chitosan tablets containing naproxen sodium, an anionic drug. The influence of buffer pH and drug:polymer ratio on the water uptake, matrix erosion, and drug release were studied. The rapid release of naproxen sodium was seen from matrices containing 100% chitosan due to loss in the matrix cohesiveness; whereas, it was relatively slow for matrices containing optimum concentration of κ-carrageenan. In-situ interaction between oppositely charged moieties resulted in the formation of polyelectrolyte complexes with stoichiometric charge ratios of unity. Fourier transform infrared (FTIR) spectroscopy and powder x-ray diffraction (PXRD) data confirmed the importance of ionic bonds in polyelectrolyte complexation. The ionic interactions between polymers were absent in matrices containing HPMC and the integrity of tablets was improved owing to the presence of viscous gel barrier.The reasons for retarded release of naproxen sodium from the chitosan matrices at different pH include poor aqueous solubility of drug, the formation of a rate-limiting polymer gel barrier along the periphery of matrices, the interaction of naproxen sodium with protonated amino groups of chitosan, and the interaction of ionized amino groups of chitosan with ionized sulfate groups of κ-carrageenan.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.