Iolanda De Marco

Rifampicin microparticles production by supercritical antisolvent precipitation

Semi-continuous supercritical antisolvent (SAS) precipitation has been used to produce Rifampicin micro- and nanoparticles with controlled particle size (PS) and particle size distribution (PSD). SAS experiments were performed using different liquid solvents. The best micronization results have been obtained using dimethyl sulfoxide (DMSO); using this solvent and operating at 40 degrees C, we obtained nanoparticles with mean diameters ranging from 0.4 to 1 microm at a pressure of 120 bar or more, and microparticles with mean diameters ranging from 2.5 to 5 microm at pressures between 90 and 110 bar. The morphology of Rifampicin precipitates was different too. Nanoparticles connected in small aggregates were obtained at pressures higher than 120 bar, whereas, spherical single microparticles were obtained operating at lower pressures. We also investigated the effect of the concentration of Rifampicin in the liquid solution on particles diameter: we observed that, increasing the liquid concentration, the mean PS increased and the PSD enlarged. XRD and HPLC analysis on treated Rifampicin showed that particles are amorphous and no degradation occurred as a consequence of supercritical processing. We attempted an explanation of the different morphologies observed considering the modification of the high pressure vapor-liquid equilibria of the ternary system Rifampicin-DMSO-CO(2) with respect to the behavior of the binary system DMSO-CO(2).

Life Cycle Assessment of Red and White Wines Production in Southern Italy

In the last years, the wine production industry has gradually focused its attention in the improvement of the product quality rather than in the production of great quantities. This tendency has allowed the entrance in the market of various small wine producers that have developed new product trademarks of good qualities on a small scale. Recently, the environmental sustainability is establishing to determine the product quality. In this study, a Life Cycle Assessment (LCA) was carried out to compare the environmental impacts and the energy efficiency of four kinds of wines made by a small producer in the southern part of Italy. The system boundary covered the industrial life-cycle stages of wine production. In particular, in this paper, four stages were considered: vinification, bottling, packaging and waste disposal treatments. The aim of the work is to compare the environmental impact of a high and medium quality wine (either in the case of white wines or in the case of red wines) to understand how to address the production toward a higher sustainability. The analysed products have been realized using different processes and different raw materials, depending on the specific characteristics and kind (red or white) of produced wine. The materials and energy consumption and the emissions to air, soil and water were reported to the chosen functional unit (1 bottle of Italian wine). The data were analysed using SimaPro 8.0.2 software and the Ecoinvent database, in accordance with the reference standard for LCA (i.e., ISO 14040-14044) to identify environmental key performance indicators (KPIs).

A review of microencapsulation methods for food antioxidants: Principles, advantages, drawbacks and applications

Bioactivities and numerous health benefits against a number of oxidative stress related diseases have been attributed to the role of dietary antioxidants. The development of physical (spray drying, lyophilization, supercritical fluid precipitation and solvent evaporation), physico-chemical (coacervation, liposomes and ionic gelation) and chemical encapsulation techniques (interfacial polymerization and molecular inclusion complexation) enable to obtain healthier and acceptable bioactive compounds. This review focuses on the impacts of microencapsulation techniques on the encapsulation characteristics of food antioxidants. Additionally, this study also provides detailed information on the principles, effective parameters, advantages, disadvantages and applications of microencapsulation techniques.

Supercritical Antisolvent Process: PVP/Nimesulide Coprecipitates

Nimesulide (NIM) is an anti-inflammatory drug, widely used in the treatment of acute pain associated with different diseases. A major limitation in its usage is due to its reduced solubility in water; therefore, large doses are required to reach the therapeutic level, with consequent undesired effects on patient’s health. In order to improve NIM dissolution rate, a possible solution is represented by its micronization. Traditional micronization techniques show several drawbacks: lack of control over the particle morphology and particle size distribution, large solvent residues and use of high temperatures. An alternative to conventional techniques is represented by supercritical carbon dioxide (scCO2) based processes. In particular, nanoparticles and microparticles of different kind of materials were successfully obtained by supercritical antisolvent (SAS) precipitation. However, when processed using SAS, nimesulide precipitated in form of large crystals or it is completely extracted by the mixture solvent/antisolvent. A solution to this problem can be the production of drug-polymer composite microspheres, using a water soluble polymer in which the drug is entrapped. In this work, NIM coprecipitation with polyvinylpyrrolidone (PVP) is proposed on pilot scale. The effects of polymer/drug ratio, concentration, pressure and temperature were investigated to identify successful operating conditions for SAS coprecipitation. Microparticles with a mean diameter ranging between 1.6 and 4.1 µm were successfully produced. Drug release analyses revealed that NIM dissolution rate from PVP/NIM microparticles was 2.5 times faster with respect to unprocessed drug. The possible precipitation mechanisms involved in the process were discussed.

Analysis of Mechanisms for PVP-Active-Agent Formulation as in Supercritical Antisolvent Spray Process

Supercritical antisolvent technology can precipitate polyvinylpyrrolidone (PVP) particles and crystallize paracetamol (PCM) crystals first separately and then together in the form of a solid dispersion. Supercritical carbon dioxide (scCO2) is used as an antisolvent. For PVP particle generation, ethanol, acetone, and mixtures of ethanol and acetone are used as solvents. The initial concentration of PVP in the solution was varied between 0.5 and 5 wt%, the operation pressure between 10 and 30 MPa, and the composition of ethanol/acetone solvent mixtures between 100 and 0 wt% of ethanol at a constant temperature of 313 K. An increase in the content of the “poor” solvent acetone in the initial solution leads to a significant decrease in mean particle size. Fully amorphous PVP powder always precipitates for all the parameters investigated.