Production of theophylline nanoparticles using rapid expansion of supercritical solutions with a solid cosolvent (RESS-SC) technique

Preparation of Erlotinib hydrochloride nanoparticles (anti-cancer drug) by RESS-C method and investigating the effective parameters

The size of the drug particles is one of the essential factors for the proper absorption of the drug compared to the dose of the drug. When particle size is decreased, drug uptake into the body increases. Recent studies have revealed that the rapid expansion of supercritical solution with cosolvent plays a significant role in preparing micron and submicron particles. This paper examines the preparation of Erlotinib hydrochloride nanoparticles using a supercritical solution through the cosolvent method for the first time. An examination of the parameters of temperature (318-338 K), pressures (15-25 MPa) and nozzle diameter (300-700 μm) was investigated by Box-Behnken design, and their respective effects on particle size revealed that the nozzle diameter has a more significant impact on particle size than the other parameters. The smallest particles were produced at temperature 338 K, pressure 20 MPa, and nozzle diameter 700 μm. Besides, the ERL nanoparticles were characterized using SEM, DLS, XRD, FTIR, and DSC analyses. Finally, the results showed that the average size of the ERL particles decreased from 31.6 μm to 200-1100 nm.

Green Processing of Neat Poly(lactic acid) Using Carbon Dioxide under Elevated Pressure for Preparation of Advanced Materials: A Review (2012-2022)

This review provides a concise overview of up-to-date developments in the processing of neat poly(lactic acid) (PLA), improvement in its properties, and preparation of advanced materials using a green medium (CO₂ under elevated pressure). Pressurized CO₂ in the dense and supercritical state is a superior alternative medium to organic solvents, as it is easily available, fully recyclable, has easily tunable properties, and can be completely removed from the final material without post-processing steps. This review summarizes the state of the art on PLA drying, impregnation, foaming, and particle generation by the employment of dense and supercritical CO₂ for the development of new materials. An analysis of the effect of processing methods on the final material properties was focused on neat PLA and PLA with an addition of natural bioactive components. It was demonstrated that CO₂-assisted processes enable the control of PLA properties, reduce operating times, and require less energy compared to conventional ones. The described environmentally friendly processing techniques and the versatility of PLA were employed for the preparation of foams, aerogels, scaffolds, microparticles, and nanoparticles, as well as bioactive materials. These PLA-based materials can find application in tissue engineering, drug delivery, active food packaging, compostable packaging, wastewater treatment, or thermal insulation, among others.

An overview on the application of supercritical carbon dioxide for the processing of pharmaceuticals

Supercritical carbon dioxide (scCO2) application in the pharmaceutical industry is still undeveloped regardless of significant research interests in this processing medium shown in the last decades. ScCO2 technologies can improve drug solubility, bioavailability, and therapeutic effect. These technologies can lead to the development of new formulations that will contribute to a decrease in drug dose, medication frequency, and increase patients' well-being. Considering the significant decrease in the price of high-pressure equipment and society's growing need for cleaner production and safer products, it is expected that symbiosis between supercritical fluid and pharmaceutical technologies will happen soon. Therefore, this review was focused on the latest contributions of scCO2 technologies to the pharmaceutical field. The main aim was to bring these technologies closer to pharmaceutical specialists. For this purpose, the most commonly used technologies were explained and discussed: the preparation of solid dispersions, polymer impregnation with drugs, and drug micro/nanoparticle production using scCO2.

A critical review on the particle generation and other applications of rapid expansion of supercritical solution

The novel particle generation processes of Active Pharmaceutical Ingredient (API)/drug have been extensively explored in recent decades due to their wide-range applications in the pharmaceutical industry. The Rapid Expansion of Supercritical Solutions (RESS) is one of the promising techniques to obtain the fine particles (micro to nano-size) of APIs with narrow particle size distribution (PSD). In RESS, supercritical carbon dioxide (SC CO₂) and API are used as solvent and solute respectively. In this literature survey, the application of RESS in the formation of fine particles is critically reviewed. Solubility of API in SC CO₂ and supersaturation are the key factors in tuning the particle size. The different approaches to model and predict the solubility of API in SC CO₂ are discussed. Then, the effect of process parameters on mean particle size and the particle size distribution are interpreted in the context of solubility and supersaturation. Furthermore, the less-explored applications of RESS in preparation of solid-lipid nanoparticles, liposome, polymorphic conversion, cocrystallization and inclusion complexation are compared with traditional processes. The solubility enhancement of API in SC CO₂ using co-solvent and its applications in particle generation are explored in published literature. The development and modifications in the conventional RESS process to overcome the limitations of RESS are presented. Finally, the perspective on RESS with special attention to its commercial operation is highlighted.

Supercritical fluid (SCF)-assisted fabrication of carrier-free drugs: An eco-friendly welcome to active pharmaceutical ingredients (APIs)

Despite the success in developing various pharmaceutical formulations, most of the active pharmaceutical ingredients (APIs)/drugs, according to the Biopharmaceutics Classification System (BCS), often suffer from various intrinsic limitations of solubility and permeability, substantially hindering their bioavailability in vivo. Regardless of the fact that the availability of different particle fabrication approaches (top-down and bottom-up) towards pharmaceutical manufacturing, the supercritical fluid (SCF) technology has emerged as one of the highly effective substitutes due to the environmentally benign nature and processing convenience, as well as the economically promising character of SCFs. The exceptional features of SCFs have endowed the fabrication of various APIs either solely or in combination with the compatible supramolecular species towards achieving improved drug delivery. Operating such APIs in high-pressure conditions often results in arbitrary-sized particulate forms, ranging from micron-sized to sub-micron/nano-sized particles. Comparatively, these SCF-processed particles offer enhanced tailorable physicochemical and morphological properties (size, shape, and surface), as well as improved performance efficacy (bioavailability and therapy) over the unprocessed APIs. Although the "carrier-based" delivery is practical among diverse delivery systems, the direct fabrication of APIs into suitable particulate forms, referred to as "carrier-free" delivery, has increased attention towards improving the bioavailability and conveying a high payload of the APIs. This review gives a comprehensive emphasis on the SCF-assisted fabrication of diverse APIs towards exploring their great potential in drug delivery. Initially, we discuss various challenges of drug delivery and particle fabrication approaches. Further, different supercritical carbon dioxide (SC-CO₂)-based fabrication approaches depending on the character of SCFs are explicitly described, highlighting their advantages and suitability in processing diverse APIs. Then, we provide detailed insights on various processing factors affecting the properties and morphology of SCF-processed APIs and their pharmaceutical applications, emphasizing their performance efficacy when administered through multiple routes of administration. Finally, we summarize this compilation with exciting perspectives based on the lessons learned so far and moving forward in terms of challenges and opportunities in the scale-up and clinical translation of these drugs using this innovative technology.

Nanoparticles and Nanocrystals by Supercritical CO2-Assisted Techniques for Pharmaceutical Applications: A Review

Many active ingredients currently prescribed show limited therapeutic efficacy, mainly due to their dissolution rate inadequate to treat the pathology of interest. A large drug particle size creates an additional problem if a specific site of action in the human body has to be reached. For this reason, active ingredient size reduction using micronization/nanonization techniques is a valid approach to improve the efficacy of active compounds. Supercritical carbon-dioxide-assisted technologies enable the production of different morphologies of different sizes, including nanoparticles and nanocrystals, by modulating operating conditions. Supercritical fluid-based processes have numerous advantages over techniques conventionally employed to produce nanosized particles or crystals, such as reduced use of toxic solvents, which are completely removed from the final product, ensuring safety for patients. Active compounds can be processed alone by supercritical techniques, although polymeric carriers are often added as stabilizers, to control the drug release on the basis of the desired therapeutic effect, as well as to improve drug processability with the chosen technology. This updated review on the application of supercritical micronization/nanonization techniques in the pharmaceutical field aims at highlighting the most effective current results, operating conditions, advantages, and limitations, providing future perspectives.

Trends on the Rapid Expansion of Supercritical Solutions Process Applied to Food and Non-food Industries

BACKGROUND

The supercritical fluids applied to particle engineering over the last years have received growing interest from the food and non-food industries, in terms of processing, packaging, and preservation of several products. The rapid expansion of supercritical solutions (RESS) process has been recently reported as an efficient technique for the production of free-solvent particles with controlled morphology and size distribution.

OBJECTIVE

In this review, we report technological aspects of the application of the RESS process applied to the food and non-food industry, considering recent data and patent survey registered in literature.

METHODS

The effect of process parameters cosolvent addition, temperature, pressure, nozzle size among others, during RESS on the size, structure and morphology of the resulted particles, and the main differences about recent patented RESS processes are reviewed.

RESULTS

Most of the experimental works intend to optimize their processes through investigation of process parameters.

CONCLUSION

RESS is a feasible alternative for the production of particles with a high yield of bioactive constituents of interest to the food industry. On the other hand, patents developed using this type of process for food products are very scarce, less attention being given to the potential of this technique to develop particles from plant extracts with bioactive substances.

Supercritical carbon dioxide-based technologies for the production of drug nanoparticles/nanocrystals - A comprehensive review

Low drug bioavailability, which is mostly a result of poor aqueous drug solubilities and of inadequate drug dissolution rates, is one of the most significant challenges that pharmaceutical companies are currently facing, since this may limit the therapeutic efficacy of marketed drugs, or even result in the discard of potential highly effective drug candidates during developmental stages. Two of the main approaches that have been implemented in recent years to overcome poor drug solubility/dissolution issues have frequently involved drug particle size reduction (i.e., micronization/nanonization) and/or the modification of some of the physicochemical and structural properties of poorly water soluble drugs. A large number of particle engineering methodologies have been developed, tested, and applied in the synthesis and control of particle size/particle-size distributions, crystallinities, and polymorphic purities of drug micro- and nano-particles/crystals. In recent years pharmaceutical processing using supercritical fluids (SCF), in general, and supercritical carbon dioxide (scCO₂), in particular, have attracted a great attention from the pharmaceutical industry. This is mostly due to the several well-known advantageous technical features of these processes, as well as to other increasingly important subjects for the pharmaceutical industry, namely their "green", sustainable, safe and "environmentally-friendly" intrinsic characteristics. In this work, it is presented a comprehensive state-of-the-art review on scCO₂-based processes focused on the formation and on the control of the physicochemical, structural and morphological properties of amorphous/crystalline pure drug nanoparticles. It is presented and discussed the most relevant scCO₂, scCO₂-based fluids and drug physicochemical properties that are pertinent for the development of successful pharmaceutical products, namely those that are critical in the selection of an adequate scCO₂-based method to produce pure drug nanoparticles/nanocrystals. scCO₂-based nanoparticle formation methodologies are classified in three main families, and in terms of the most important role played by scCO₂ in particle formation processes: as a solvent; as an antisolvent or a co-antisolvent; and as a "high mobility" additive (a solute, a co-solute, or a co-solvent). Specific particle formation methods belonging to each one of these families are presented, discussed and compared. Some selected amorphous/crystalline drug nanoparticles that were prepared by these methods are compiled and presented, namely those studied in the last 10-15 years. A special emphasis is given to the formation of drug cocrystals. It is also discussed the fundamental knowledge and the main mechanisms in which the scCO₂-based particle formation methods rely on, as well as the current status and urgent needs in terms of reliable experimental data and of robust modeling approaches. Other addressed and discussed topics include the currently available and the most adequate physicochemical, morphological and biological characterization methods required for pure drug nanoparticles/nanocrystals, some of the current nanometrology and regulatory issues associated to the use of these methods, as well as some scale-up, post-processing and pharmaceutical regulatory subjects related to the industrial implementation of these scCO₂-based processes. Finally, it is also discussed the current status of these techniques, as well as their future major perspectives and opportunities for industrial implementation in the upcoming years.

Nanotechnology: from In Vivo Imaging System to Controlled Drug Delivery

Science and technology have always been the vitals of human's struggle, utilized exclusively for the development of novel tools and products, ranging from micro- to nanosize. Nanotechnology has gained significant attention due to its extensive applications in biomedicine, particularly related to bio imaging and drug delivery. Various nanodevices and nanomaterials have been developed for the diagnosis and treatment of different diseases. Herein, we have described two primary aspects of the nanomedicine, i.e., in vivo imaging and drug delivery, highlighting the recent advancements and future explorations. Tremendous advancements in the nanotechnology tools for the imaging, particularly of the cancer cells, have recently been observed. Nanoparticles offer a suitable medium to carryout molecular level modifications including the site-specific imaging and targeting. Invention of radionuclides, quantum dots, magnetic nanoparticles, and carbon nanotubes and use of gold nanoparticles in biosensors have revolutionized the field of imaging, resulting in easy understanding of the pathophysiology of disease, improved ability to diagnose and enhanced therapeutic delivery. This high specificity and selectivity of the nanomedicine is important, and thus, the recent advancements in this field need to be understood for a better today and a more prosperous future.

Nanosizing techniques for improving bioavailability of drugs

The poor solubility of significant number of Active Pharmaceutical Ingredients (APIs) has become a major challenge in the drug development process. Drugs with poor solubility are difficult to formulate by conventional methods and often show poor bioavailability. In the last decade, attention has been focused on developing nanocrystals for poorly water soluble drugs using nanosizing techniques. Nanosizing is a pharmaceutical process that changes the size of a drug to the sub-micron range in an attempt to increase its surface area and consequently its dissolution rate and bioavailability. The effectiveness of nanocrystal drugs is evidenced by the fact that six FDA approved nanocrystal drugs are already on the market. The bioavailabilities of these preparations have been significantly improved compared to their conventional dosage forms. There are two main approaches for preparation of drug nanocrystals; these are the top-down and bottom-up techniques. Top-down techniques have been successfully used in both lab scale and commercial scale manufacture. Bottom-up approaches have not yet been used at a commercial level, however, these techniques have been found to produce narrow sized distribution nanocrystals using simple methods. Bottom-up techniques have been also used in combination with top-down processes to produce drug nanoparticles. The main aim of this review article is to discuss the various methods for nanosizing drugs to improve their bioavailabilities.