Solid-State Characterization of Spironolactone 1/3 Hydrate

A Spironolactone-Based Prototype of an Innovative Biomedical Patch for Wound Dressing Applications

The electrospinning process is an effective technique for creating micro- and nanofibers from synthetic and natural polymers, with significant potential for biomedical applications and drug delivery systems due to their high drug-loading capacity, large surface area, and tunable release times. Poly(L-lactic acid) (PLLA) stands out for its excellent thermo-mechanical properties, biodegradability, and bioabsorbability. Electrospun PLLA nanofibrous structures have been extensively investigated as wound dressings, sutures, drug delivery carriers, and tissue engineering scaffolds. This study aims to create and characterize electrospun PLLA membranes loaded with spironolactone (SP), mimicking active compounds of Ganoderma lucidum (GL), to develop a biodegradable patch for topical wound-healing applications. GL, a medicinal mushroom, enhances dermal wound healing with its bioactive compounds, such as polysaccharides and ganoderic acids. Focusing on GL extracts-obtained through green extraction methods-and innovative drug delivery, we created new fibers for wound-healing potential applications. To integrate complex mixtures of bioactive compounds into the fibers, we developed a prototype using a single pure substance representing the extract mixture. This painstaking work presents the results of the fabricating, wetting, moisture properties, material resilience, and full characterization of the product, providing a robust rationale for the fabrication of fibers imbued with more complex extracts.

Terahertz spectroscopy detection of lithium citrate tetrahydrate and its dehydration kinetics

Lithium citrate (LC) as a common food additive and also a psychiatric drug, usually in the form of tetrahydrate can gradually lose its crystalline water and convert into LC anhydrate at temperatures higher than the room temperature. In order to quickly distinguish the tetrahydrate from the anhydrate and to study the dehydration kinetics of the LC hydrates under the influence of the temperature, terahertz time-domain spectroscopy (THz-TDS) is utilized in this work. Experimental results show that the LC tetrahydrate at room temperature has an obvious absorption peak around 1.66 THz, while the LC anhydrate has no absorption peak at 0.5-3.0 THz. The absorption peak intensity of the LC tetrahydrate decreases continuously upon heating from 25 to 100 °C. Based on the normalized absorption peak area of the LC tetrahydrate around 1.66 THz, variation of its dehydration rate with the heating temperature is investigated and their relationship is fitted by the Arrhenius equation. The reaction activation energy of the LC tetrahydrate is derived to be 495.1 ± 17.8 J/g with a deviation of about 3.7% from the traditional difference scanning calorimetry (DSC) measurement. These results indicate that THz-TDS can provide an efficient method to detect crystalline hydrates and can be applied to study the dehydration kinetics of crystalline hydrates with advantages of being fast, label-free and accurate.

The Effect of Solvent Vapor Annealing on Drug-Loaded Electrospun Polymer Fibers

Electrospinning has emerged as a powerful strategy to develop controlled release drug delivery systems but the effects of post-fabrication solvent vapor annealing on drug-loaded electrospun fibers have not been explored to date. In this work, electrospun poly(ԑ-caprolactone) (PCL) fibers loaded with the hydrophobic small-molecule spironolactone (SPL) were explored. Immediately after fabrication, the fibers are smooth and cylindrical. However, during storage the PCL crystallinity in the fibers is observed to increase, demonstrating a lack of stability. When freshly-prepared fibers are annealed with acetone vapor, the amorphous PCL chains recrystallize, resulting in the fiber surfaces becoming wrinkled and yielding shish-kebab like structures. This effect does not arise after the fibers have been aged. SPL is found to be amorphously dispersed in the PCL matrix both immediately after electrospinning and after annealing. In vitro dissolution studies revealed that while the fresh fibers show a rapid burst of SPL release, after annealing more extended release profiles are observed. Both the rate and extent of release can be varied through changing the annealing time. Further, the annealed formulations are shown to be stable upon storage.