STUDIES IN DISSOLUTION ENHANCEMENT OF ATENOLOL, PART I

The objective of this study was to design atenolol tablets with fast i n vitro release rates. Different polymers were screened as possible ca rriers to enhance atenolol dissolution. Binary systems using povidone (PVP), crospovidone (PVP-CL), polyvinilpyrrolidone/vinylacetate (PVP/V A), and Eudragit(R)E were prepared. The physical properties of solid d ispersions, compared to physical mixtures, were analysed using X-ray d iffraction (XRD) and differential scanning calorimetry (DSC). The solu bility and the release rate of atenolol from solid dispersions were co mpared to the drug alone. The influence of various parameters (type of polymer, drug to polymer ratio, pH) on the solubility and dissolution rate of the drug was also evaluated. The results of DSC and X-ray ana lyses of solid dispersions attested that the drug was always present i n a crystalline form in the PVP-CL and Eudragit(R)E systems, while wit h the high content of PVP and PVP/VA an amorphisation of the atenolol was detectable. On the other hand, the diffraction patterns and the DS C thermograms of the physical mixtures revealed that to some extent th e drug was always present in a crystalline form. An improvement in sol ubility and dissolution rate of atenolol with PVP and PVP-CL was obtai ned. (C) 1998 Published by Elsevier Science B.V. All rights reserved.