THERMAL-ANALYSIS, SPECTROSCOPY AND LYOAVA ILABILITY OF SOLID DISPERSIONS OF OXAZEPAM AND POLYOXYETHYLENE GLYCOL-4000 AND POLYOXYETHYLENE GLYCOL-6000

We have determined the dissolution kinetic of binary eutectic composit ion oxazepam - PEG 4000R and oxazepam - PEG 6000: drug 5% and polymer 95% in different samples, physical mixe, fused mixture, precipitate. W e have evaluated mixing enthalpies and observed a good agreement betwe en dissolution kinetic data and mixing enthalpies data (absolute value s) of fused mixture, physical mixe, and precipitate in decreasing orde r, valuable for PEG 4000 and PEG 6000. Using H-1 NMR, we have found re sults in agreement with kinetic dissolution.