A thermoplastic composition comprises a copolycarbonate comprising 25 to 100 mole percent of a first carbonate unit derived from a dihydroxy aromatic compound having the formula ##STR00001## wherein R.sup.a' and R.sup.b' are C.sub.1-12 alkyl, T is a C.sub.5-16 cycloalkylene, a C.sub.5-16 cylcloalkylidene, a C.sub.1-5 alkylene, a C.sub.1-5 alkylidene, a C.sub.6-13 arylene, a C.sub.7-12 arylalkylene, C.sub.7-12 arylalkylidene, a C.sub.7-12 alkylarylene, or a C.sub.7-12 arylenealkyl, and r and s are each independently 1 to 4, and r and s are 1 to 4; and 0 to 75 mole percent of a second carbonate unit, wherein the first carbonate unit and second carbonate unit are not identical; a polysiloxane-polycarbonate copolymer comprising 0.15 to 30 weight percent of a polysiloxane block comprising siloxane units of the formula ##STR00002## wherein E is on average of 4 to 60 units, and 70 to 99.85 weight percent of a third carbonate unit, wherein an article having a thickness of 3.2 mm and molded from the thermoplastic composition has a Dynatup total energy of greater than 50 Joules, as measured at a constant speed of 3.3 to 3.6 m/sec at 23.degree. C. according to ASTM D3763-02. A method of making and articles prepared therefrom are also disclosed.