Supercritical Antisolvent Precipitation of Quercetin Systems: Preliminary Experiments

Flavonoids have attracted a lot of attention due to their antioxidant, antitumor and antibacterial activities. Quercetin (3,5,7,3,4-pentahydroxyflavone) is a polyphenolic flavonoid that shows several biological effects including a strong inhibitory effect on the growth of several human and animal cancer cell lines and enhances the antiproliferative effect of cisplatin both in-vitro and in-vivo. In spite of a variety of its biological effects. Quercetin is very poorly soluble in water, which has limited its absorption upon oral administration. As known, the solubility of drug is often due to the increase of the surface/volume ratio which implies the increase of the number of surface atoms (or molecules) with respect to the number of bulk atoms (or molecules). With this aim, we investigated the use of supercritical antisolvent (SAS) technique for Quercetin microparticles generation finding the best operative conditions through the Peng Robinson’s Equation of State. The obtained simulation behaviors were confirmed by experimental precipitation: the physicochemical characterizations of the samples were also performe

Drug-polymer filled micro-containers for oral delivery loaded using supercritical CO₂ aided-impregnation

In this work we present an effective loading technique of micro-containers for oral drug delivery of a poorly water soluble drug in a solid dispersion with polymer. By combining inkjet printing and supercritical CO2 impregnation we load ketoprofen in a solid dispersion with poly(vinylpyrrolidone) (PVP) into cylindrical micro-containers providing unidirectional release. Both the printing and the impregnation step can be tuned in order to control drug loading with accuracy in the range of micro-grams

The banff 2019 kidney meeting report (I): updates on and clarification of criteria for T cell- and antibody-mediated rejection.

The XV. Banff conference for allograft pathology was held in conjunction with the annual meeting of the American Society for Histocompatibility and Immunogenetics in Pittsburgh, PA (USA) and focused on refining recent updates to the classification, advances from the Banff working groups, and standardization of molecular diagnostics. This report on kidney transplant pathology details clarifications and refinements to the criteria for chronic active (CA) T cell-mediated rejection (TCMR), borderline, and antibody-mediated rejection (ABMR). The main focus of kidney sessions was on how to address biopsies meeting criteria for CA TCMR plus borderline or acute TCMR. Recent studies on the clinical impact of borderline infiltrates were also presented to clarify whether the threshold for interstitial inflammation in diagnosis of borderline should be i0 or i1. Sessions on ABMR focused on biopsies showing microvascular inflammation in the absence of C4d staining or detectable donor-specific antibodies; the potential value of molecular diagnostics in such cases and recommendations for use of the latter in the setting of solid organ transplantation are presented in the accompanying meeting report. Finally, several speakers discussed the capabilities of artificial intelligence and the potential for use of machine learning algorithms in diagnosis and personalized therapeutics in solid organ transplantation

The Banff 2019 Kidney Meeting Report (I): Updates on and clarification of criteria for T cell– and antibody-mediated rejection

The XV. Banff conference for allograft pathology was held in conjunction with the annual meeting of the American Society for Histocompatibility and Immunogenetics in Pittsburgh, PA (USA) and focused on refining recent updates to the classification, advances from the Banff working groups, and standardization of molecular diagnostics. This report on kidney transplant pathology details clarifications and refinements to the criteria for chronic active (CA) T cell–mediated rejection (TCMR), borderline, and antibody-mediated rejection (ABMR). The main focus of kidney sessions was on how to address biopsies meeting criteria for CA TCMR plus borderline or acute TCMR. Recent studies on the clinical impact of borderline infiltrates were also presented to clarify whether the threshold for interstitial inflammation in diagnosis of borderline should be i0 or i1. Sessions on ABMR focused on biopsies showing microvascular inflammation in the absence of C4d staining or detectable donor-specific antibodies; the potential value of molecular diagnostics in such cases and recommendations for use of the latter in the setting of solid organ transplantation are presented in the accompanying meeting report. Finally, several speakers discussed the capabilities of artificial intelligence and the potential for use of machine learning algorithms in diagnosis and personalized therapeutics in solid organ transplantation

Solubility estimation of drugs in ternary systems of interest for the antisolvent precipitation processes

Drug solubility in compressed carbon dioxide is usually low, and for this reason, CO2 is not considered a suitable solvent. However, it can be used as antisolvent to crystallize a solute from a liquid solution. The choice of optimal pressure and the CO2/drug solution ratio is a crucial point of the process, and these values must be optimized. An estimation method based on the Peng\u2013Robinson\u2019s equation of state is presented here with which to calculate the solubility of drugs such as Acetaminophen, Acyclovir, Atenolol, Carbamazepine, Ibuprofen, Naproxen, Nimesulide, and Sotalol hydrochloride in mixtures of CO2 and common organic solvents at a constant temperature but a variable pressure. The model temperature was 298K for Ibuprofen and Naproxen, 315K for Acetaminophen and 313K for any other systems. This method is a practical and rapid alternative to experimental determination

Solubility of pharmaceutical compounds in supercritical carbon dioxide

The manuscript aims to estimate the solubility behavior of pharmaceutical compounds in supercritical fluids using an activity coefficient model based on linear solvation energy relationships. The parameters of this model were further generalized as a function of the properties of the pharmaceutical compounds. The selected compounds include antioxidants, antibiotics, steroids and anti-inflammatory and their solubility data were collected from literature. This model is able to estimate the solubility of the pharmaceutical compounds in supercritical carbon dioxide within acceptable accuracy for more than 60% of the proposed systems

Extraction Behavior of Lipids Obtained from Spent Coffee Grounds Using Supercritical Carbon Dioxide

Supercritical carbon dioxide (sc-CO2) extraction was applied to extract lipids from spent coffee grounds. The effects of different process conditions on the extraction yield and composition of the extracts were investigated by response surface methodology. A comparison of the experimental results with those obtained by conventional solvent extraction was also performed. In all these samples, the main fatty acids were rich in palmitic and linoleic acids. Moreover, a new method was developed and validated for the gas chromatographic analysis of sterols and tocopherols. The results demonstrate that sc-CO2 extraction is principally a potential candidate method for the extraction of lipids and high value-added compounds from residues/by-products