Chrono-Modulated Pulsatile Drug Delivery System of Hydralazine HCL An Effective Treatment Method for Hypertension

This study focuses on the development of a novel oral pulsatile drug delivery system for Hydralazine HCl using a core-in-cup tablet design to achieve time-specific drug release. The formulation comprises a core tablet containing the active drug, surrounded by an impermeable hydrophobic cup of cellulose acetate propionate and a hydrophilic top layer made of swellable polymers Sodium Alginate, HPMC K4M, and Sodium Carboxy methyl cellulose at varying concentrations. Core tablets were prepared via direct compression and evaluated for physical parameters including thickness (3.6–3.7 mm), hardness (3.4–3.8 kg/cm²), and friability (<1%). Powder blends exhibited good micromeritic properties with an angle of repose (24.28°–28.56°) and Carr’s index (8.32%–17.53%). Finished tablets showed consistent drug content (97.23%–99.01%). FTIR analysis confirmed compatibility between drug and excipients. In-vitro release studies in phosphate buffer (pH 6.8) over 12 hours revealed sustained and delayed drug release, with cumulative release between 96.37% and 98.04%. Among all formulations, HPMC K4M demonstrated superior lag time and sustained release, making formulation HHP-4 the most optimized. This pulsatile system presents a promising strategy for chronotherapeutic management of hypertension.