In vitro dissolution test of tamoxifen citrate preparations

The Tamoxifen Citrate is available in oral tablet and is highly used as an endocrines therapy for breast cancer. Products from assorted makers bioavailability problems has been associated to the incomplete dissolution of the tablets. We determined the dissolution in vitro of five pharmaceutical preparations of the Tamoxifen Citrate available in the Brazilian market, Novaldex, Tecnotax, Zita, Tamoxifen (TEVA) and Tamoxifeno (PHARMACIA) all containing 10 mg of active drug. The methodology was conducted according to the in vitro dissolution test from USP XXIII. Other test such as mass uniformity, content uniformity and hardness were accomplished seeking to relate physical characteristics with the in vitro dissolution of these preparations. All the formulations presented liberation more than 75% of the active drug in 30 minutes. Any relationship was not observed between the in vitro dissolution, the average weight, the mass uniformity and the hardness of the tablets whereas the liberation was proportional to the tamoxifen citrate content. Although one of the tested products did present a higher dissolution profiles in comparison to the other tested preparation.