Applications of Supercritical Anti-Solvent Process in Preparation of Solid Multicomponent Systems

Inhalation Dosage Forms: A Focus on Dry Powder Inhalers and Their Advancements

In this review, an extensive analysis of dry powder inhalers (DPIs) is offered, focusing on their characteristics, formulation, stability, and manufacturing. The advantages of pulmonary delivery were investigated, as well as the significance of the particle size in drug deposition. The preparation of DPI formulations was also comprehensively explored, including physico-chemical characterization of powders, powder processing techniques, and formulation considerations. In addition to manufacturing procedures, testing methods were also discussed, providing insights into the development and evaluation of DPI formulations. This review also explores the design basics and critical attributes specific to DPIs, highlighting the significance of their optimization to achieve an effective inhalation therapy. Additionally, the morphology and stability of 3 DPI capsules (Spiriva, Braltus, and Onbrez) were investigated, offering valuable insights into the properties of these formulations. Altogether, these findings contribute to a deeper understanding of DPIs and their development, performance, and optimization of inhalation dosage forms.

Viscosity Measurement of CO2-Solvent Mixtures for the Study of the Morphology and Size of Crystalline Particles Obtained Using Supercritical Antisolvent Precipitation

The viscosity values of CO2-dimethylphormamide, chloroform, methanol, isopropanol, ethyl acetate, acetone, and dimethyl sulfoxide mixtures were measured at a pressure of 150 bar and a temperature of 313 K. The correlation of the mean size of levofloxacin hydrochloride and malonic acid particles precipitated using the SAS method with the viscosity of the used CO2-solvent mixtures is shown. The high viscosity of the mixtures leads to slower mixing of the solution and the antisolvent. Therefore, crystallization occurs at large fractions of the solvent, and as a consequence at a lower supersaturation. This causes the formation of larger particles when using more viscous solvents in SAS.

Monitoring Distribution of the Therapeutic Agent Dimethyl Sulfoxide via Solvatochromic Shift of Albumin-Bound Indocyanine Green

We recently developed a novel hyperspectral excitation-resolved near-infrared fluorescence imaging system (HER-NIRF) based on a continuous-wave wavelength-swept laser. In this study, this technique is applied to measure the distribution of the therapeutic agent dimethyl sulfoxide (DMSO) by utilizing solvatochromic shift in the spectral profile of albumin-bound Indocyanine green (ICG). Using wide-field imaging in turbid media, complex dynamics of albumin-bound ICG are measured in mixtures of dimethyl sulfoxide (DMSO) and water. Phantom experiments are conducted to evaluate the performance of the HER-NIRF system. The results show that the distribution of DMSO can be visualized in the wide-field reflection geometry. One of the main purposes of the DMSO is to act as a carrier for other drugs, enhancing their effects by facilitating skin penetration. Understanding the solubility and permeability of drugs in vivo is very important in drug discovery and development. Hence, this HER-NIRF technique has great potential to advance the utilization of the therapeutic agent DMSO by mapping its distribution via the solvatochromic shift of ICG. By customizing the operational wavelength range, this system can be applied to any other fluorophores in the near-infrared region and utilized for a wide variety of drug delivery studies.

Blending of the Thermodynamically Incompatible Polyvinyl Chloride and High-Pressure Polyethylene Polymers Using a Supercritical Fluid Anti-Solvent Method (SEDS) Dispersion Process

The experimental solubility data of polyvinyl chloride (PVC) and high-pressure polyethylene (HPPE) in organic solvents (toluene, dichloromethane, and chloroform) at temperatures ranging from 308.15 to 373.15 K at atmospheric pressure are reported in the present paper. The solubility of the polymers (PVC and HPPE) in organic solvents (toluene, dichloromethane, and chloroform) was studied at temperatures between 298 and 373 K. The supercritical SEDS dispersion of PVC and HPPE polymer blends at pressures between 8.0 and 25 MPa and at temperatures from 313 to 333 K are reported in the present work. The kinetics of crystallization and phase transformation in polymer blends obtained by blending in a melt, and using the supercritical SEDS method, have been studied. The effect of the HPPE/PVC ratio on the thermal and mechanical characteristics of the polymer blends has been studied. For all studied polymer blends and pure polymers obtained using the SEDS method, the heat of fusion Δ_fusH exceeds the values obtained by blending in the melt by 1.5 to 5) times. The heat of fusion of the obtained polymer blends is higher than the additive value; therefore, the degree of crystallinity is higher, and this effect persists after heat treatment. The relative elongation decreases for all polymer blends, but their tensile strength increases significantly.

Particle preparation of pharmaceutical compounds using supercritical antisolvent process: current status and future perspectives

The low aqueous solubility and subsequently slow dissolution rate, as well as the poor bioavailability of several active pharmaceutical ingredients (APIs), are major challenges in the pharmaceutical industry. In this review, the particle engineering approaches using supercritical carbon dioxide (SC CO₂) as an antisolvent are critically reviewed. The different SC CO₂-based antisolvent processes, such as the gas antisolvent process (GAS), supercritical antisolvent process (SAS), and a solution-enhanced dispersion system (SEDS), are described. The effect of process parameters such as temperature, pressure, solute concentration, nozzle diameter, SC CO₂ flow rate, solvent type, and solution flow rate on the average particle size, particle size distribution, and particle morphology is discussed from the fundamental perspective of the SAS process. The applications of the SAS process in different formulation approaches such as solid dispersion, polymorphs, cocrystallization, inclusion complexation, and encapsulation to enhance the dissolution rate, solubility, and bioavailability are critically reviewed. This review highlights some areas where the SAS process has not been adequately explored yet. This review will be helpful to researchers working in this area or planning to explore SAS process to particle engineering approaches to tackle the challenge of low solubility and subsequently slow dissolution rate and poor bioavailability.

Development of carboxymethyl chitosan-coated zein/soy lecithin nanoparticles for the delivery of resveratrol

The objective of this work is to formulate a zein-based nanocomposite for the delivery of natural polyphenols. A proprietary atomizing/antisolvent precipitation (AAP) process was used to prepare carboxymethyl chitosan (CMC)-coated zein/soy lecithin (SL) nanoparticles (ZLC NPs). At a suitable mass ratio of zein/SL/CMC (100 : 30 : 30), ZLC NPs with desirable redispersibility and physicochemical stability were successfully fabricated. After that, resveratrol (Res) as the representative natural polyphenol was encapsulated in ZLC NPs. The optimized Res/ZLC NPs exhibited a spherical morphology, small size (259.43 ± 2.47 nm), large zeta potential (-47.7 ± 0.66 mV), and high encapsulation efficiency (91.32 ± 4.01%) and loading capacity (5.27 ± 0.35%). Further characterization indicated that Res was encapsulated in the hydrophobic core of the ZLC matrix in an amorphous state. Compared to free Res, Res/ZLC NPs showed a 2.55-fold increase in the Res dissolution rate, a 2.27-fold increase in bioaccessibility, and a 1.69-fold increase in ABTS˙⁺ scavenging activity. Also, Res/ZLC NPs showed a higher Res retention rate (>68.0%) than free Res (<35.0%) over 45 days of storage. Therefore, ZLC NPs have promising potential as vehicles for natural polyphenols.

Zein-based nanoparticles: Preparation, characterization, and pharmaceutical application

Zein, as one of the natural and GRAS proteins in plant, is renewable, nontoxic, biocompatible and biodegradable. Over the past decade, many research efforts have been devoted to zein-based biomaterials for several industrial applications. Combining with research experiences in our research group, the preparation methods, characterizations and pharmaceutical applications of zein-based nanoparticles were summarized in this review. Zein NPs with different particle nanostructures have been prepared by chemical crosslinking, desolvating, dispersing and micromixing strategies. The pharmaceutical applications of zein NPs are mainly focus on the drug delivery. Zein NPs can improve the drug stability, increase the oral bioavailability, control the drug release and enhance the drug targeting, thereby improving the pharmaceutical effect effectively. More efforts are required to analyze the relationship among preparation methods, particle nanostructures and pharmaceutical properties in virtue of quality by design approach, and further promote the scale-up production and clinical application of zein NPs.

Fabrication of betamethasone micro- and nanoparticles using supercritical antisolvent technology: In vitro drug release study and Caco-2 cell cytotoxicity evaluation

Poor solubility limits the pharmacological activities of betamethasone (BM), including its anti-inflammatory and anti-allergic effects. To improve the aqueous solubility and dissolution rate of BM, supercritical antisolvent (SAS) technology was used to prepare BM microparticles and BM-polyvinylpyrrolidone (PVP) solid dispersion nanoparticles. The effects of temperature, pressure, solution feeding rate, and drug concentration on particle formation were investigated using both single-factor and orthogonal experimental methods, and the optimal preparation process was screened. The physicochemical properties of the BM particles were characterized by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray diffraction. After the SAS process, the particle size was reduced significantly and the crystalline shape was altered, which considerably increased the solubility and dissolution rate of BM. Furthermore, the toxicity of BM to live cells was reduced because of the BM-PVP solid dispersions.

Enhanced Efficacy of Carvedilol by Utilization of Solid Dispersion and Other Novel Strategies: A Review

Carvedilol is classified as a second class drug of Biopharmaceutical classification system (BCS), and it is an excellent beta blocker and vasodilating agent. It is used in a diverse range of disease states. Despite having tremendous advantages, the drug cannot be used effectively and productively due to aquaphobicity and poor bioavailability. To overcome this limitation, numerous novel approaches and tactics have been introduced over the past few years, such as Selfmicro emulsifying drug delivery systems (SMEDDS), nanoparticles, solid dispersions and liposomal drug delivery. The present review aims to accentuate the role of solid dispersion in improving the dissolution profile and aqua solubility of carvedilol and also to emphasize other novel formulations of carvedilol proposed to prevail the limitations of carvedilol. Solid dispersion and other novel approaches were found to play a significant role in overcoming the drawbacks of carvedilol, among which solid dispersion is the most feasible and effective approach being used worldwide. Reduced particle size, more wettability, and large surface area are obtained by the implementation of solid dispersion technique, hence improving carvedilol solubility and bioavailability.

Particle crystallization by supercritical antisolvent processing techniques: the case of Retama raetam powder for pharmaceutical purposes

In this work, the Supercritical AntiSolvent process has been used to generate micronized crystals of Retama raetam. The process was performed using ethanol and CO2 as solvent and antisolvent, respectively. Recrystallization was made at various temperatures (30–50 °C) and pressures (8–12 MPa) using a constant flow rate of supercritical CO2 (2 kg/h). We have been also varied the solution flow rate and its volume to identify conditions leading to spheroidal powder morphology. Size and morphology have been characterized by scanning electron microscopy and ImageJ software. The spraying of the supercritical solution directing the flow towards the precipitator results in the deposition of fine particles with uniform morphology at the bottom, and of a porous film adhering to the precipitator wall. For that reason, thermodynamic and hydrodynamic aspects are discussed so as to rationalize the powder and spongious film characteristics and provide a new way to control the SAS process applied to plant derivatives.

Contribution of Nanoscience Research in Antioxidants Delivery Used in Nutricosmetic Sector

Nanoscience applications in the food and cosmetic industry offer many potential benefits for consumers and society. Nanotechnologies permit the manipulation of matter at the nanoscale level, resulting in new properties and characteristics useful in food and cosmetic production, processing, packaging, and storage. Nanotechnology protects sensitive bioactive compounds, improves their bioavailability and water solubility, guarantees their release at a site of action, avoids contact with other constituents, and masks unpleasant taste. Biopolymeric nanoparticles, nanofibers, nanoemulsions, nanocapsules, and colloids are delivery systems used to produce food supplements and cosmetics. There are no barriers to nanoscience applications in food supplements and cosmetic industries, although the toxicity of nano-sized delivery systems is not clear. The physicochemical and toxicological characterization of nanoscale delivery systems used by the nutricosmeceutic industry is reviewed in this work.

Recent Progress of Antisolvent Crystallization

Antisolvent crystallization is a significant unit operation in the pharmaceutical industry, especially on drug crystal properties optimization. This paper firstly highlights the applications of antisolvent crystallization in crystal engineering. Antisolvent...

Investigating Antiarthritic Potential of Nanostructured Clove Oil (Syzygium aromaticum) in FCA-Induced Arthritic Rats: Pharmaceutical Action and Delivery Strategies

The combined application of clove oil in a lipid nanocarrier opens a promising avenue for bone and joints therapy. In this study, we successfully developed a tunable controlled-release lipid platform for the efficient delivery of clove oil (CO) for the treatment of rheumatoid arthritis (RA). The ultra-small nanostructured lipid carriers co-loaded with CO (CONCs) were developed through an aqueous titration method followed by microfluidization. The CONCs appeared to be spherical (particle size of 120 nm), stable (zeta potential of -27 mV), and entrapped efficiently (84.5%). In toluene:acetone:glacial acetic acid (90:9:1 percent v/v/v) solvent systems, high-performance thin layer chromatography (HPTLC) analysis revealed the primary components in CO as eugenol (RF = 0.58). The CONCs greatly increased the therapeutic impact of CO in both in vitro and in vivo biological tests, which was further supported by excellent antiarthritic action. The CONC had an antiarthritic activity that was slightly higher than neat CO and slightly lower than standard, according to our data. The improved formulation inhibited serum lysosomal enzymes and proinflammatory cytokines while also improving hind leg function. This study provides a proof of concept to treat RA with a new strategy utilizing essential oils via nanodelivery.

Application of commercially available mesoporous silica for drug dissolution enhancement in oral drug delivery

Due to the high number of poorly water-soluble active pharmaceutical ingredients, oral drug delivery development has become challenging. One of the strategies to enhance drug solubility and to achieve high oral bioavailability is to formulate such compounds into amorphous solid dispersions. In recent years, porous materials have been investigated as possible carriers into which a drug can be adsorbed, such as mesoporous silica, in particular. Unlike the ordered mesoporous network of silica, non-ordered silica already has a "generally regarded as safe" status, and is already used as an excipient in pharmaceutical and cosmetic products. Thus, it is reasonable to expect that products that contain solid dispersions with non-ordered carriers will reach the market sooner and more easily than those with ordered mesoporous carriers. The emphasis of this review is therefore on non-ordered commercially available mesoporous silica and the progress that has been made in development of the use of these materials for improved dissolution rates in oral drug delivery. First, a thorough categorisation of the drug loading methods is presented, followed by discussion on the most important characteristics of solid dispersions (i.e., physical state, stability, drug release). Finally, manufacturability and production of a final solid dosage form are considered.

Supercritical Carbon Dioxide as a Green Alternative to Achieve Drug Complexation with Cyclodextrins

Cyclodextrins are widely used in pharmaceutics to enhance the bioavailability of many drugs. Conventional drug/cyclodextrin complexation techniques suffer from many drawbacks, such as a high residual content of toxic solvents in the formulations, the degradation of heat labile drugs and the difficulty in controlling the size and morphology of the product particles. These can be overcome by supercritical fluid technology thanks to the outstanding properties of supercritical CO₂ (scCO₂) such as its mild critical point, its tunable solvent power, and the absence of solvent residue after depressurization. In this work the use of scCO₂ as an unconventional medium to achieve the complexation with native and substituted cyclodextrins of over 50 drugs, which belong to different classes, are reviewed. This can be achieved with different approaches such as the “supercritical solvent impregnation” and “particle-formation” techniques. The different techniques are discussed to point out how they affect the complexation mechanism and efficiency, the physical state of the drug as well as the particle size distribution and morphology, which finally condition the release kinetics and drug bioavailability. When applicable, the results obtained for the same drug with various cyclodextrins, or different complexation techniques are compared with those obtained with conventional approaches.