Abstract
Valsartan, a type 1 selective receptor for angiotensin, is primarily used in the treatment of hypertension and, in a minority, to treat coronary artery disease and heart failure. Among its adverse effects, it can be mentioned malaise, dizziness and headache. Furthermore, in the conventional form of release, it may cause patient non-compliance with treatment and need for multiple dosages, which lead to the possibility of reduction in therapeutic efficiency. To avoid these disadvantages, the present work aimed at the production of valsartan particles for delayed and extended release of the drug. The composition of the particles was based on the polymer blend of sericin and alginate. Sericin, present in the cocoons of the Bombyx mori silkworm, is a water soluble globular protein discharged into effluent from the silk industry. Its chemical structure allows it to be used for the formation of blends with other polymers, aiming at the improvement of its properties. Alginate, which was commercially obtained, is a polysaccharide obtained from brown algae, widely used in pharmaceutical applications. In order to evaluate the incorporation of valsartan into the aforementioned polymer blend, formulations with alginate only and formulations with different amounts of alginate initially added were developed. The evaluation was accomplished by means of incorporation efficiency and in vitro dissolution tests in simulated gastrointestinal environment. Sericin was shown to increase both the drug incorporation efficiency and the release time in enteric media. The best result was obtained for the formulation composed of the sericin and alginate blend, with the lowest amount of alginate. An 82.75 ± 2.61 % incorporation efficiency and extended release (about 28 hours) was achieved.
