Abstract: A sustained-release pharmaceutical composition in a form of a tablet comprises (a) alprazolam in an amount of about 0.1 mg to about 5 mg per tablet, (b) a high viscosity HPMC and (c) a low viscosity HPMC, wherein the total amount of HPMC is about 110 mg to about 135 mg per tablet and the high and low viscosity HPMCs are present in a weight ratio of about 40:60 to about 60:40. The tablet can be a member of a series having different amounts of alprazolam in the range from about 0.1 mg to about 5 mg, members of the series having substantially equal total tablet weight and being substantially bioequivalent. The composition is useful in treatment of CNS conditions and disorders including general anxiety disorder, anxiety associated with depression, panic disorder and panic attacks.