Investigation of effect of complexing agent and processing method on solubility of Efonidipine

Nanosponges are versatile carriers due to their exceptional capability to improve the solubility of poorly water-soluble drugs, taste masking and enhancement of stability. This study investigates potential of nanosponges, prepared by crosslinking β-cyclodextrin with diphenyl carbonate in 1:4 ratio for enhancing solubility of Efonidipine. Nanosponges were characterized in terms of particle size. Phase solubility studies and solution state interaction studies were employed to understand the nature and strength of drug: nanosponge complexation. Complexes were prepared by kneading method and spray drying. Saturation solubility, in vitro dissolution studies and molecular modeling studies were performed. Complexes were characterized by differential scanning calorimetry (DSC), infrared spectroscopy, X ray powder diffraction (XRPD) and scanning electron microscopy. Phase solubility studies revealed 1:2 complexation between drug and carriers. Saturation solubility studies showed significant solubility increase with both beta CD and nanosponges. The increase was higher in case of spray dried complexes in all media. An 18 fold increase was observed in case of spray dried complexes in distilled water. DSC and PXRD confirmed amorphization of drug in the complexes. Thus solubility enhancement of EFD could be attributed to complexation and amorphization. Molecular modeling studies revealed the mode of entrapment of efonidipine in the carriers. In conclusion the versatility of nanosponges in encapsulating both hydrophilic and hydrophobic drug molecules holds immense promise for personalized medicine and targeted therapy, ultimately leading to improved patient outcomes. Moreover, the study introduces the efficacy of spray drying as a scalable and practical approach to maximize the solubility-enhancing benefits of nanosponges. This research highlights the potential of nanosponges to overcome a fundamental challenge in pharmaceuticals, opening new avenues for drug delivery and therapeutic advancement. Keywords: Nanosponges, β -cyclodextrin, inclusion complexes, solubility enhancement, molecular modelling