Formulation and Evaluation of Pulsatile Drug Delivery System of Telmisartan

The present study was undertaken to develop and evaluate pulsatile tablets of Telmisartan designed to release the drug after a specific lag time, synchronized with the circadian rhythm of hypertension, particularly addressing the early morning surge in blood pressure. Core tablets were prepared using direct compression method and formulated with varying concentrations of superdisintegrants—Croscarmellose Sodium and Sodium Starch Glycolate. Among the batches, C2, containing 4% Croscarmellose Sodium, demonstrated the most rapid disintegration (28 sec) and highest drug release at 15 minutes (98.84%), indicating it as the optimal core formulation. Press-coated pulsatile tablets were developed using the optimized core (C2) and a coating of HPMC K100M and HPMC E5 in different ratios. The lag time and drug release profile varied with polymer composition. Formulation F4, with a 3:1 ratio of HPMC K100M to HPMC E5, exhibited the desired lag phase of approximately 5 hours followed by rapid drug release, aligning with the target for morning dosing. All pre-compression and post-compression parameters of both core and coated tablets were within acceptable limits, ensuring good flow properties, mechanical strength, and uniformity. The in-vitro drug release followed Korsmeyer-Peppas kinetics, suggesting anomalous (non-Fickian) drug release behavior, governed by both diffusion and erosion mechanisms. Stability studies conducted on the optimized formulation (F4) under accelerated conditions showed no significant changes in drug content, appearance, or release profile, indicating good stability over 3 months. The developed press-coated pulsatile tablets of Telmisartan successfully achieved a controlled lag phase and targeted drug release, potentially improving therapeutic outcomes and patient compliance in hypertensive patients with a circadian rhythm-based symptom pattern.