Potential of Nitrofurantoin Cyclodextrin Nanosponge Complex to Enhance Solubility and Masking Bitter Taste

This study aimed to produce b-cyclodextrin (β-CD) based nanosponges (NS) loaded with nitrofurantoin (NFN) to improve oral bioavailability, solubility, and dissolution rate while concealing bitter tastes. The cross-linker diphenyl carbonate and β-CD were reacted in various ratios (1:1, 1:2, 1:4, 1:6, and 1:8) to produce NFN-loaded NS. The developed NS were evaluated for phase solubility study, particle size, drug loading, polydispersity index, scanning electron microscope (SEM), zeta potential, fourier transform infrared (FTIR), differential scanning calorimetry (DSC), a study of phosphate buffer at pH 7.2 for in-vitro release and taste masking ability in human volunteers. Pure NFN showed nearly 100 mcg/mL solubility in ditilled water while at 1:8 (β-CD: DPC) ratio the solubility was found to be 250 mcg/mL, i.e., nearly 2.5 fold enhancement in solubility was observed. The SEM of the NFN-loaded NS (1:8 β-CD: DPC ratio) showed highly spherical surface morphology. For formulation containing a 1:8 proportion of β-CD to DPC, the average particle size was measured at 324.78 ± 10.45 nm, possessing a low polydispersity index of 0.196 ± 0.054. It was found that the zeta potential’s value was -20.59 ± 0.4 mV, indicating sufficient electrostatic repulsion to maintain particle dispersion. FTIR, DSC study reveled excellent drug and excipient compatability. As compared to pure NFN, NFN-loaded NS showed faster release in pH 7.2 phosphate buffer. Research conducted in-vitro showed a gradual release of NFN from pure NFN throughout a two-hour period. The plain NFN suspension was found to have a pronounced bitterness. With 3.95 ± 0.57 as the average score, while the NFN nanosponges (1:8 ratio) had a mean bitterness score of only 0.10 ± 0.00. These findings suggest that the NFN (1:8 ratio) has the capacity to thoroughly cover up the bitter taste of NF.