Role of Cyclodextrins and Drug Solid State Properties on Flufenamic Acid Dissolution Performance from Tablets

QbD Assisted Systematic Review for Optimizing the Selection of PVP as a Ternary Substance in Enhancing the Complexation Efficiency of Cyclodextrins: a Pilot Study

Inclusion complexes require higher concentration of Beta cyclodextrins (βCD) resulting in increased formulation bulk, toxicity, and production costs. This systematic review offers a comprehensive analysis using Quality by design (QbD) as a tool to predict potential applications of Polyvinylpyrrolidone (PVP) as a ternary substance to address issues of inclusion complexes. We reviewed 623 documents from 2013 to 2023 and Eighteen (18) research papers were selected for statistical and meta-analysis using the QbD concept to identify the most critical factors for selecting drugs and effect of PVP on inclusion complexes. The QbD analysis revealed that Molecular weight (MW), Partition coefficient (Log P), and the auxiliary substance ratio directly affected complexation efficiency (CE), thermodynamic stability in terms of Gibbs free energy (ΔG), and percent drug release. However, Stability constant (Ks) remained unaffected by any of these parameters. The results showed that low MW (250), median Log P (6), and a βCD: PVP ratio of 2:3 would result in higher CE, lower G, and improved drug release. PVP improves drug solubility, enhances delivery and therapeutic outcomes, and counteracts increased drug ionization due to decreased pH. In certain cases, its bulky nature and hydrogen bonding with CD molecules can form non-inclusion complexes. The findings of the study shows that there is potential molecular interaction between PVP and β-cyclodextrins, which possibly enhances the stability of inclusion complexes for drug with low MW and log P values less than 9. The systematic review shows a comprehensive methodology based on QbD offers a replicable template for future investigations into drug formulation research.

Thixotropic Hydrogels Based on Laponite® and Cucurbituril for Delivery of Lipophilic Drug Molecules

Nowadays the use of hydrogels for biomedical purposes is increasing because of their interesting features that allow the development of targeted drug delivery systems. Herein, hydrogel based on Laponite® (Lap) clay mineral as gelator and cucurbit[6]uril (CB[6]) molecules were synthetized for the delivery of flufenamic acid (FFA) for potential topical application. Firstly, the interaction between CB[6] and FFA was assessed by UV-vis spectroscopic measurements and molecular modeling calculations. Then, the obtained complex was used as filler for Lap hydrogel (Lap/CB[6]/FFA). The properties of the hydrogel in terms of viscosity and, self-repair abilities were investigated; its morphology was imaged by scanning electron and polarized optical microscopies. Furthermore, the changes in the hydrodynamic radii and in the colloidal stability of CB[6]/Lap mixture were investigated in terms of translational diffusion from dynamic light scattering and ζ-potential measurements. Finally, the kinetic in vitro release of FFA, from Lap/CB[6]/FFA hydrogel, was studied in a medium mimicking the pH of skin and the obtained results were discussed both by an experimental point of view and by molecular modeling calculations.