The Effect of Gelucire 50/13 on Release Rate of Naproxen in Solid Dispersions Prepared by PEG 4000

Background and Solubility behavior of a drug is one of the key determinants of its oral bioavailability. The bioavailability may be enhanced by increasing the solubility and dissolution rate of drug by combining the drug with a hydrophilic carrier. Naproxen is a poor water non-soluble analgesic and anti- inflammatory drug. A possible way of overcoming the naproxen low aqueous solubility is to alter the physical properties of the drug by preparing a solid dispersion. In this study, Gelucire 50/13 and PEG 4000 were employed to produce solid dispersions with naproxen. Naproxen solid dispersions were prepared in various amounts of drug and polymer (PEG4000) using hot melting method. The influence of several amounts of gelucire 50/13 was also studied. Dissolution studies, Differential scanning calorimetry (DSC), Fourier–transform infrared spectroscopy (FTIR), and X-ray powder diffractometry (XRD) were used to evaluate any interaction between the drug and other components in solid dispersions. According to dissolution study, drug release from solid dispersions and physical mixture were higher than that of the pure drug. Also, dissolution rate of solid dispersions and physical mixtures enhanced by increasing the concentration of polyetilen glycol. The result of DSC and FTIR showed that there was no chemical interaction between the drug and the polymer. XRD patterns indicated that piroxicam exists in its solid state in all solid dispersions. The increased dissolution rate of naproxen by solid dispersion technique could be due to increase wettability and hydrophilic nature of carrier and surfactants.