Nanocrystal Formulation of Manidipine HCl: An Attempt to Enhance Solubility of Poorly Soluble Drug

Background: Manidipine Hydrochloride (MND) is a long-acting dihydropyridine-type calcium antagonist and antihypertensive drug categorized under the Biopharmaceutics Classification System (BCS) Class II. Despite its therapeutic benefits, MND suffers from poor physicochemical and biological properties due to its high lipophilicity and low aqueous solubility, which pose challenges to formulation and drug delivery. Improving the solubility of such hydrophobic drugs is crucial for enhancing their bioavailability. While conventional methods for solubility enhancement exist, drug nanocrystal systems have emerged as a promising approach for addressing solubility issues in poorly soluble drugs. Objective: To formulate and evaluate nanocrystals of MND using spray-drying technology to enhance its solubility and address limitations associated with its hydrophobicity. Method: MND nanocrystals were prepared using a spray-drying technique, a cost-effective and scalable method that converts liquid formulations into dry powder through atomization and drying processes. The spray-dried nanocrystals were characterized by their particle size, morphology, solubility, and dissolution rate. Comparative studies evaluated the solubility enhancement achieved with the nanocrystals versus raw MND. Result: The nanocrystals demonstrated a significant reduction in particle size and enhanced surface area, resulting in improved aqueous solubility and dissolution rates compared to raw MND. Spray-drying facilitated the uniform formation of nanocrystals, ensuring better dispersion and dissolution performance. Conclusion: Spray-dried MND nanocrystals proved to be a viable strategy for overcoming solubility and bioavailability challenges. This approach offers a promising avenue for enhancing the clinical efficacy of poorly soluble drugs like MND.