Objective: The objective of this study was to develop extended release (ER) pellets of Bosentan, an endothelin receptor antagonist using fluid bed processor (coating).Method: The ER drug pellets of Bosentan were prepared using fluid bed coating. These drug-loaded pellets were further coated with ethyl cellulose of two viscosity grades and Eudragit as rate controlling polymers individual and in combination, hypromellose as pore former and binder, acetyl tributyl citrate as plasticizer, and magnesium stearate as anti-adhering agent.Results: The drug release was extended up to 24 h, and the drug release was mainly depends on the polymer type and polymer proportion. In vivo study of Bosentan, ER pellets were performed in healthy rabbits (New Zealand, White) of either sex weighing (3.0–3.3 kg) and were divided into two separate groups, each group consisting of 6 animals. Maximum plasma concentration (Cmax), maximum time (Tmax), area under the curve (AUC0-t), elimination rate constant (Kel), and half-life (T1/2) were studied for optimized formulation. Formulation was releasing the drug for a prolonged period of time.Conclusion: By the above results, it was observed that the prepared pellets could release the drug for an extended period when compared with the conventional dosage form of Bosentan, optimized formulation was shown longer half-life and Cmax indicates its acceptability. Finally, ER pellets of Bosentan were prepared for the treatment of pulmonary artery hypertension by fluid bed processor.

Aim and Objective: The main objective of this study was to formulate extended release pellets of torsemide, a pyridine-sulfonyl urea type loop diuretic. Materials and Methods: The preparations of torsemide pellets were prepared by extrusion-spheronization method. The prepared pellets were then coated with ethyl cellulose of different grades and Eudragit L30 D 55 and Eudragit NM 30 D grades at different concentrations as release retardant polymers using fluid bed processor, in this formulation hydroxypropyl methylcellulose used as a pore former and binder, microcrystalline cellulose PH101 as diluents and water used as a solvent. Results: The prepared pellets were evaluated for drug content, in vitro dissolution, differential scanning caloriemetry (DSC), Fourier transforms infrared (FTIR), and scanning electron microscopy (SEM). The drug release was extended up to 24 h and drug release was depended on polymer grade and polymer proportion. The optimized formulation showed 99 ± 0.11 release in 24 h. The DSC and FTIR studies were showed the compatibility of the drug with a polymer, i.e., no drug-polymer interaction. Using SEM, it was shown that the torsemide pellets were porous and spherical in shape. Accelerated stability studies showed good similarity with the initial formulation indicated good stability for 6 months. In vivo, pharmacokinetic studies were conducted in rabbits by parallel design and pharmacokinetic parameters were calculated. Conclusion: By the above results, it can be concluded that the above-prepared pellets of torsemide could be able to extend the drug release by avoiding problems such as dose dumping, more gastric residence time, and improve the patient compliance. In vivo studies in rabbits were shown the increased half-life and bioavailability for a long duration.