Nanosponges-based Drug Delivery System for the Cosmeceutical Applications of Stabilized Ascorbic Acid

L-Ascorbic acid (AA) is a highly unstable compound, thus, limiting its use in pharmaceutical and cosmetic products, particularly at higher concentrations.

This study aimed to stabilize the highly sensitive molecule (AA) by encapsulating it in β- cyclodextrin nanosponges (β-CD NS) that can be used further in preparing cosmeceuticals products with higher AA concentrations and enhanced stability.

The NS has been synthesized by the melting method. The AA was encapsulated in β-CD NS by the freeze-drying process. The prepared NS were characterized by FTIR spectrometry, SEM, Atomic Force Microscopy (AFM), zeta sizer, Differential Scanning Calorimetry (DSC), and the physical flow characteristics were also studied. The in vitro drug release was carried out on the Franz apparatus using a combination of two methods: sample & separate and dialysis membrane. The assay was performed using a validated spectrometric method.

The entrapment efficiency of AA in β-CD NS indicated a good loading capacity (83.57±6.35%). The FTIR, SEM, AFM, and DSC results confirmed the encapsulation of AA in β-CD NS. The particle size, polydispersity index, and zeta potential results ascertained the formation of stabilized monodisperse nanoparticles. The physical flow characteristics showed good flow properties. Around 84% AA has been released from the NS in 4 h following the Korsmeyer-Peppas model. The AA-loaded NS remained stable for nine months when stored at 30±2°C/65±5% RH.

It is concluded that the prepared NS can protect the highly sensitive AA from degradation and provide an extended-release of the vitamin. The prepared AA-loaded β-CD NS can be used to formulate other cosmeceutical dosage forms with better stability and effect.