Development of pimobendan chewable tablets: pharmaceutical characterization and comparative pharmacokinetic evaluation in beagle dogs

Pimobendan (PIM) is an important cardiovascular drug widely used for the long-term management of cardiac diseases in dogs. Commercially available PIM chewable tablets (PCTs) have been developed to facilitate oral administration; however, systematic studies on the formulation development, pharmaceutical characteristics, stability, and in vivo pharmacokinetic behavior of PCTs remain limited. Therefore, this study aimed to develop a PIM chewable tablet formulation and systematically evaluate its pharmaceutical properties, stability, and pharmacokinetic characteristics in beagle dogs in comparison with a commercially available formulation. The developed PCTs exhibited satisfactory pharmaceutical characteristics, including appearance, weight uniformity, content uniformity, mechanical properties, and moisture content. The tablets showed a dissolution profile comparable to that of the commercially available formulation, with more than 80% of PIM released within 30 min. Stability studies demonstrated that the tablets maintained satisfactory quality under accelerated and long-term storage conditions, although light exposure resulted in decreased drug content and 30-min cumulative performance, indicating the need for light-protective storage. Following oral administration in beagle dogs, the developed tablets showed rapid absorption and produced pharmacokinetic profiles comparable to those of the commercial formulation. No significant differences were observed between the two formulations in the major pharmacokinetic parameters, including C max , T max , T last , T 1/2 , AUC 0–∞ , Vz/F, CL/F, and MRT 0–∞ . A PIM chewable tablet formulation with satisfactory pharmaceutical properties and stability was successfully developed. The developed PCTs exhibited dissolution behavior and pharmacokinetic characteristics comparable to those of the commercially available formulation. These findings provide useful information for the formulation development and pharmaceutical evaluation of PCTs and indicate that the developed formulation may represent a potential oral formulation for PIM administration in dogs.