Improved dissolution and anti-inflammatory activity of ibuprofen-polyethylene glycol 8000 solid dispersion systems

Background: The purpose of this study was to develop ibuprofen (IB)-polyethylene glycol (PEG) 8000 solid dispersions (SDs) and investigate them for in vitro dissolution and in vivo anti-inflammatory activity. Materials and Methods: IB- PEG 8000 SDs were prepared by fusion method using varying combination ratios of IB and PEG 8000. Characterization based on surface morphology, particle size, absolute drug content, and Fourier transform infrared (FT-IR) spectroscopy was carried out on the SDs. The in vitro release of IB from the SDs was performed in simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.4 ) without enzymes, whereas the anti-inflammatory activity was evaluated using egg albumin-induced rat paw edema model. Results: Greenish brown, discrete, and irregularly shaped SDs of mean particle size range 113.5 ± 2.5-252.5 ± 1.9 µm, which were stable over 3 months, were obtained. The drug content of the SDs ranged from 73.4 ± 2.9 % to 83.5 ± 2.7%. Although the drug content increased with increased concentration of PEG 8000 in the SDs, the mean particle size decreased with increased concentration of PEG 8000 in the SDs. The FT-IR results indicate no strong chemical interaction of IB and PEG 8000 in the SDs. There was marked increase in the dissolution rate of IB from the SDs (P < 0.05) as compared to pure IB and physical mixture. The dissolution was better in SIF than in SGF. The increased dissolution rate of IB may be due to the formation of microcrystals, increased wettability and dispersibility in PEG 8000. The SDs showed good anti-inflammatory properties achieving up to 90% edema inhibition at 6 h while the pure sample of IB had 77% edema inhibition at 6 h. Conclusion: SDs based on IB-PEG 8000 is a good approach to enhance the dissolution rate and anti-inflammatory activity of IB, thus, encouraging further development of the SDs.