A study of hydrophobic domain formation of polymeric drug precipitation inhibitors in aqueous solution

Despite the widespread use of polymers as precipitation inhibitors in supersaturating drug formulations, the current understanding of their mechanisms of action is still incomplete. Specifically, the role of hydrophobic drug interactions with polymers by considering possible supramolecular conformations in aqueous dispersion is an interesting topic. Accordingly, this study investigated the tendency of polymers to create hydrophobic domains, where lipophilic compounds may nest to support drug solubilisation and supersaturation. Fluorescence spectroscopy with the environment-sensitive probe pyrene was compared with atomistic molecular dynamics simulations of the model drug fenofibrate (FENO). Subsequently, kinetic drug supersaturation and thermodynamic solubility experiments were conducted. As a result, the different polymers showed hydrophobic domain formation to a varying degree and the molecular simulations supported interpretation of fluorescence spectroscopy data. Molecular insights were gained into the conformational structure of how the polymers interacted with FENO in solution phase, which apart from nucleation and crystal growth effects, determined drug concentrations in solution. Notable was that even at the lowest polymer concentration of 0.01 %, w/v, there were polymer-specific solubilisation effects of FENO observed and the resulting reduction in apparent drug supersaturation provided relevant knowledge both from a mechanistic and practical perspective.

XGB Modeling Reveals Improvement of Compressive Strength of Cement-Based Composites with Addition of HPMC and Chitosan

This study investigates the improvement in the compressive strength of cellulose/cement-based composites. Methyl cellulose (MC), carboxymethyl cellulose (CMC), and hydroxypropyl cellulose (HPMC) are separately used as the cellulose phase with different wt%. Graphene oxide (GO) and zoledronic acid (ZOL) are used as additives for bone regeneration for various formulations. Utilizing Extreme Gradient Boosting (XGB) modeling, this research demonstrates the roles of the choice of the cellulose phase, wt% of cement phase, % gelatin, % citric acid, degradation time, and concentration of GO and ZOL in influencing compressive strength. The XGB regression model, with an R2 value of 0.99 (~1), shows the predictive power of the model. Feature importance analysis demonstrates the significance of cellulose choice and the addition of chitosan in enhancing compressive strength. The correlation heatmap reveals positive associations, emphasizing the positive influence of HPMC and CMC compared with MC and the substantial impact of chitosan and citric acid on compressive strength. The model's predictive accuracy is validated through predicted compressive strength values with experimental observations, providing insights for optimizing cellulose-reinforced cements and enabling tailored material design for enhanced mechanical performance.

Hydroxypropyl Cellulose/Pluronic-Based Composite Hydrogels as Biodegradable Mucoadhesive Scaffolds for Tissue Engineering

Recently, the development of new materials with the desired characteristics for functional tissue engineering, ensuring tissue architecture and supporting cellular growth, has gained significant attention. Hydrogels, which possess similar properties to natural cellular matrixes, being able to repair or replace biological tissues and support the healing process through cellular proliferation and viability, are a challenge when designing tissue scaffolds. This paper provides new insights into hydrogel-based polymeric blends (hydroxypropyl cellulose/Pluronic F68), aiming to evaluate the contributions of both components in the development of new tissue scaffolds. In order to study the interactions within the hydrogel blends, FTIR and ¹HNMR spectroscopies were used. The porosity and the behavior in moisture medium were highlighted by SEM and DVS analyses. The biodegradability of the hydrogel blends was studied in a simulated biological medium. The hydrogel composition was determinant for the scaffold behavior: the HPC component was found to have a great influence on the BET and GAB areas, on the monolayer values estimated from sorption-desorption isotherms and on mucoadhesivity on small intestine mucosa, while the Pluronic F68 component improved the thermal stability. All blends were also found to have good mechanical strength and increased biocompatibility on the NHDF cell line. Based on their particular compositions and increased mucoadhesivity on small intestine mucosa, these polymeric blends could be effective in the repair or recovery of damaged cell membranes (due to the contribution of Pluronic F68) or in control drug-delivery intestinal formulations.

Recent Trends in Assessment of Cellulose Derivatives in Designing Novel and Nanoparticulate-Based Drug Delivery Systems for Improvement of Oral Health

Natural polymers are revolutionizing current pharmaceutical dosage forms design as excipient and gained huge importance because of significant influence in formulation development and drug delivery. Oral health refers to the health of the teeth, gums, and the entire oral-facial system that allows us to smile, speak, and chew. Since years, biopolymers stand out due to their biocompatibility, biodegradability, low toxicity, and stability. Polysaccharides such as cellulose and their derivatives possess properties like novel mechanical robustness and hydrophilicity that can be easily fabricated into controlled-release dosage forms. Cellulose attracts the dosage design attention because of constant drug release rate from the precursor nanoparticles. This review discusses the origin, extraction, preparation of cellulose derivatives and their use in formulation development of nanoparticles having multidisciplinary applications as pharmaceutical excipient and in drug delivery, as bacterial and plant cellulose have great potential for application in the biomedical area, including dentistry, protein and peptide delivery, colorectal cancer treatment, and in 3D printable dosage forms.