For poorly soluble orally administered drugs, the rate of absorption is often controlled by the rate of dissolution of the drug in the astrointestinal tract. In literature many technological methods of enhancing the dissolution characteristics of slightly water-soluble drugs
to improve bioavailability have been reported, such as micronization, use of systems with a hydrophilic soluble carrier such as lactose, or solid deposition of the drug upon the surface of a superdisintegrant agent . The atenolol, a cardio-selective b-blocker agent, is slightly
soluble in water, as reported in The Italian Pharmacopoeia , and is characterized by a low oral bioavailability. The aim of this research was to carry out formulation studies to design atenolol tablets with in vitro fast release rates. In our previous paper, after a preliminary screening
by solid dispersion analysis, povidone (PVP) and crospovidone (PVP-CL) were identified as the optimal hydrophilic carriers to enhance the in vitro dissolution rate of the drug. PVP and PVP-CL are commonly used as carriers to modify the solubility and the dissolution of poorly soluble drugs in several solid dosage forms.Furthermore, because of its highly hydrophilic character, rapid water uptake, and good swelling properties, PVPCL is widely used as a tablet disintegrant (2,3,7–9). This study encompassed the formulation of granulates in a 10-
liter high-shear mixer and tablet preparation. To determine the optimal formulation step by step, the dissolution properties, and echnological and flow characteristics of all samples were evaluated and the release profiles were compared to the Italian commercial tablets and to the granulate used for their preparation (TenorminÒ mg 100, Zeneca, Milan, Italy).
