Supercritical Fluid Technologies for the Incorporation of Synthetic and Natural Active Compounds into Materials for Drug Formulation and Delivery

In vivo toxicity of chitosan-based nanoparticles: a systematic review

Chitosan nanoparticles have been extensively utilised as polymeric drug carriers in nanoparticles formulations due to their potential to enhance drug delivery, efficacy, and safety. Numerous toxicity studies have been previously conducted to assess the safety profile of chitosan-based nanoparticles. These toxicity studies employed various methodologies, including test animals, interventions, and different routes of administration. This review aims to summarise research on the safety profile of chitosan-based nanoparticles in drug delivery, with a focus on general toxicity tests to determine LD50 and NOAEL values. It can serve as a repository and reference for chitosan-based nanoparticles, facilitating future research and further development of drugs delivery system using chitosan nanoparticles. Publications from 2014 to 2024 were obtained from PubMed, Scopus, Google Scholar, and ScienceDirect, in accordance with the inclusion and exclusion criteria.The ARRIVE 2.0 guidelines were employed to evaluate the quality and risk-of-bias in the in vivo toxicity studies. The results demonstrated favourable toxicity profiles, often exhibiting reduced toxicity compared to free drugs or substances. Acute toxicity studies consistently reported high LD50 values, frequently exceeding 5000 mg/kg body weight, while subacute studies typically revealed no significant adverse effects. Various routes of administration varied, including oral, intravenous, intraperitoneal, inhalation, and topical, each demonstrating promising safety profiles.

Supercritical CO2 in the Development of Highly Efficient Composite Cathodes for Li-S Batteries

Conventional Li-S battery cathode synthesis routes are time-consuming, energy-intensive, use toxic solvents, and yet fail to effectively confine sulfur into carbon matrices, reducing the cathode efficiency. Supercritical CO₂ (scCO2) presents notable benefits as a "green solvent" due to its affordability, chemical inertness, recyclability, non-flammability, and non-toxicity. It eliminates the need for energy-intensive post-heat treatments, providing a more sustainable and efficient option. CO2 in supercritical state gains unique gas-like and liquid-like properties that enable precise sulfur loading, uniform encapsulation, and improved sulfur-carbon interactions, which enhance conductivity and reaction kinetics. Recent studies show that cathodes prepared using scCO2 exhibit exceptional electrochemical performance, including long-term cycling stability and high coulombic efficiency. The versatility of scCO2 in infiltrating various host architectures also makes it suitable for a wide range of cathode designs. Despite its tremendous potential, this advanced synthesis technology is often overlooked in textbooks, underscoring the need for awareness within the research community. This review highlights the remarkable features of scCO2 and examine up-to-date research progress, focusing on its application in developing high-performance carbon/sulfur composite cathodes. An application-focused audience would benefit from a summary of this review, as they reveal new Li-S cathode synthesis technologies that haven't been widely explored or discussed.

Navigating translational research in nanomedicine: A strategic guide to formulation and manufacturing

Over the past two decades, extensive research has focused on both the fundamental and applied aspects of nanomedicine, driven by the compelling advantages that nanoparticles offer over their bulk counterparts. Despite this intensive research effort, fewer than 100 nanomedicines have been approved by the U.S. Food and Drug Administration and the European Medicines Agency since 1989. This disparity highlights a substantial gap in translational research, reflecting the disconnect between the prolific research in nanomedicine and the limited number of products that successfully reach and sustain themselves in the market. For instance, the nanomedicine DepoCyt, which received FDA approval in 1999 for the treatment of lymphomatous meningitis, was discontinued in 2017 due to persistent manufacturing issues. To address similar translational challenges, this review aims to identify and analyse issues related to the formulation design and manufacturing of nanomedicines. It provides an overview of the most prevalent manufacturing technologies and excipients used in nanomedicine production, followed by a critical evaluation of their clinical translatability. Furthermore, the review presents strategies for the rational formulation design and optimization of nanomedicine manufacturing, adhering to the principles of quality-by-design and quality risk management.

Supercritical Techniques for Pharmaceutical Applications

Supercritical fluid technology is an innovative approach that has been extensively explored in various research fields, since it offers a way to limit or replace the use of organic solvents in numerous industrial processes [...].

Development of Cholinium-Based API Ionic Liquids with Enhanced Drug Solubility: Biological Evaluation and Interfacial Properties

We report an efficient sustainable two-step anion exchange synthetic procedure for the preparation of choline API ionic liquids (Cho-API-ILs) that contain active pharmaceutical ingredients (APIs) as anions combined with choline-based cations. We have evaluated the in vitro cytotoxicity for the synthesized compounds using three different cells lines, namely, HEK293 (normal kidney cell line), SW480, and HCT 116 (colon carcinoma cells). The solubility of APIs and Cho-API-ILs was evaluated in water/buffer solutions and was found higher for Cho-API-ILs. Further, we have investigated the antimicrobial potential of the pure APIs, ILs, and Cho-API-ILs against clinically relevant microorganisms, and the results demonstrated the promise of Cho-API-ILs as potent antimicrobial agents to treat bacterial infections. Moreover, the aggregation and adsorption properties of the Cho-API-ILs were observed by using a surface tension technique. The aggregation behavior of these Cho-API-ILs was further supported by conductivity and pyrene probe fluorescence. The thermodynamics of aggregation for Cho-API-ILs has been assessed from the temperature dependence of surface tension. The micellar size and their stability have been studied by dynamic light scattering, transmission electron microscopy, and zeta potential. Therefore, the duality in the nature of Cho-API-ILs has been explored with the upgradation of their physical, chemical, and biopharmaceutical properties, which enhance the opportunities for advances in pharmaceutical sciences.

Aerogels as Carriers for Oral Administration of Drugs: An Approach towards Colonic Delivery

Polysaccharide aerogels have emerged as a highly promising technology in the field of oral drug delivery. These nanoporous, ultralight materials, derived from natural polysaccharides such as cellulose, starch, or chitin, have significant potential in colonic drug delivery due to their unique properties. The particular degradability of polysaccharide-based materials by the colonic microbiota makes them attractive to produce systems to load, protect, and release drugs in a controlled manner, with the capability to precisely target the colon. This would allow the local treatment of gastrointestinal pathologies such as colon cancer or inflammatory bowel diseases. Despite their great potential, these applications of polysaccharide aerogels have not been widely explored. This review aims to consolidate the available knowledge on the use of polysaccharides for oral drug delivery and their performance, the production methods for polysaccharide-based aerogels, the drug loading possibilities, and the capacity of these nanostructured systems to target colonic regions.

Intravitreal implants manufactured by supercritical foaming for treating retinal diseases

Chronic retinal diseases, such as age-related macular degeneration (AMD), are a major cause of global visual impairment. However, current treatment methods involving repetitive intravitreal injections pose financial and health burdens for patients. The development of controlled drug release systems, particularly for biological drugs, is still an unmet need in prolonging drug release within the vitreous chamber. To address this, green supercritical carbon dioxide (scCO2) foaming technology was employed to manufacture porous poly(lactic-co-glycolic acid) (PLGA)-based intravitreal implants loaded with dexamethasone. The desired implant dimensions were achieved through 3D printing of customised moulds. By varying the depressurisation rates during the foaming process, implants with different porosities and dexamethasone release rates were successfully obtained. These implants demonstrated controlled drug release for up to four months, surpassing the performance of previously developed implants. In view of the positive results obtained, a pilot study was conducted using the monoclonal antibody bevacizumab to explore the feasibility of this technology for preparing intraocular implants loaded with biologic drug molecules. Overall, this study presents a greener and more sustainable alternative to conventional implant manufacturing techniques, particularly suited for drugs that are susceptible to degradation under harsh conditions.

Generation of Highly Antioxidant Submicron Particles from Myrtus communis Leaf Extract by Supercritical Antisolvent Extraction Process

Submicron particles have been produced from an ethanolic extract of Myrtus communnis leaves using supercritical carbon dioxide technology, hereinafter referred to as Supercritical Antisolvent Extraction (SAE). The influence of pressure (9-20 MPa), temperature (308 and 328 K) and injection rate (3 and 8 mL/min) on the particles' precipitation has been investigated, and it has been confirmed that increases in pressure and temperature led to smaller particle sizes. The obtained particles had a quasi-spherical shape with sizes ranging from 0.42 to 1.32 μm. Moreover, the bioactivity of the generated particles was assessed and large contents of phenolic compounds with a high antioxidant activity were measured. The particles were also subjected to in vitro studies against oxidative stress. The myrtle particles demonstrated cytoprotective properties when applied at low concentrations (1 μM) to macrophage cell lines.

Applications and Challenges of Supercritical Foaming Technology

With economic development, environmental problems are becoming more and more prominent, and achieving green chemistry is an urgent task nowadays, which creates an opportunity for the development of supercritical foaming technology. The foaming agents used in supercritical foaming technology are usually supercritical carbon dioxide (ScCO₂) and supercritical nitrogen (ScN₂), both of which are used without environmental burden. This technology can reduce the environmental impact of polymer foam production. Although supercritical foaming technology is already in production in some fields, it has not been applied on a large scale. Here, we present a detailed analysis of the types of foaming agents currently used in supercritical foaming technology and their applications in various fields, summarizing the technological improvements that have been made to the technology. However, we have found that today's supercritical technologies still need to address some additional challenges to achieve large-scale production.