Supercritical Carbon Dioxide Extraction of Lyophilized Aristotelia chilensis (Mol.) Stuntz Berries as Pre-treatment for Enhanced Anthocyanin Recovery

The supercritical carbon dioxide extraction of lyophilized berries of Aristotelia chilensis (Mol.) Stuntz was studied as possible pre-treatment for enhanced anthocyanin recovery. Effect of pressure, temperature, and process time on the extracted oil yields and on the anthocyanins recovery in the pre-treated fractions were considered. The operating parameters were optimized using the central composite design, and extractions were run in the pressure, temperature, and time ranges of 99.6 to 200.4 bar, 36.6 to 53.4 degrees C, and 0.7-2.3 h. The successive multiple regression analysis indicated pressure and time as major influencing parameters on the extraction yield. Those parameters induced no clear changes in the fatty acid composition of almost all the extracted oils, obtaining an aver-age linoleic acid amount between 35-44 % weight in the lipophilic fractions. Standard-ized methanol extractions demonstrated the influence of the different conditions in the SCO2 pre-treatment processes, resulting in extracted anthocyanin increments ranging from 9 to 26 %

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

Influence of the microwave technology on the physical-chemical properties of solid dispersion with Nimesulide

This work describes a new approach to prepare solvent-free solid dispersions (SDs) for Nimesulide (NMS), involving the use of microwaves irradiation (MW). In particular, the microwave technology has been considered in order to prepare an enhanced release dosage form for the poorly soluble drug Nimesulide (NMS), employing Gelucire\uae 50/13 and Poloxamer 188 (Lutrol\uae F 68) as surfactant carriers. Their physicochemical characteristics and dissolution properties were compared to the corresponding physical mixtures and the drug alone. The results attested a correspondence of the solid state of the drug before and after the irradiation treatment and that an amorphisation form of the drug in SD systems was obtained. After six months this data was confirmed

Sustained-release solid dispersions of ibuprofenprepared by microwave irradiation

The paper is devoted to the investigation of microwave irradiation (MW) for the preparation of solvent free solid dispersion (SD). Precisely, sustained release solid dispersions containing different drug-to-polymer ratios were developed by means of microwave technology using ibuprofen (IBU) as a model drug and glyceryl monostarate (Imwitor 900, GM) as a lipophilic sustained release agent. Their physical characterizations were determined by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), hot-stage microscopy (HSM). Through the dissolution rates studies, the in vitro drug performance of the SD was evaluated. The physical characterizations revealed a substantial correspondence of the drug solid state before and after MW treatment while drug-carrier interactions in the SD were attested. The dissolution studies of the irradiated samples showed that the matrices based on Imwitor 900 were able to promote a sustained release of the drug. A mathematical approach suggested that IBU release from solid dispersion was essentially due to matrix erosion. In conclusion we can affirm that the microwave technique could be considered as a new and interesting method to prepare drug-carrier systems

Dichloromethane: Physicochemical Properties, Applications and Environmental Effects

This book chapter is aimed to provide, with a consistent section concerning the physical and chemical issues, the industrial uses of dichloromethane with particular attention to pharmaceutical, nutraceutical, and food purposes. Solubility data in different substances, were reported and estimated by means of Abraham\u2019s model. Due to its toxicity and possible carcinogenic action, methods to avoid residuals in the treated materials such as pharmaceutical, nutraceutical or food compounds will be discussed. As an example, a literature experimental test on dichloromethane removal from a pharmaceutical drug, by supercritical carbon dioxide, is reported. Moreover, two other literature applications of dichloromethane in pharmaceutical technology field were considered

Piroxicam solid state studies after processing with SAS technique

Supercritical carbon dioxide (SCO2) was used as anti-solvent to precipitate Piroxicam, a nonsteroidal anti-inflammatory drug, from different organic solvents (acetone, ethyl acetate and dichloromethane). Physicochemical properties of the samples were analyzed before and after the treatment to highlight possible changes in the form of the crystals. The solid state analysis of both products untreated and treated with CO2, showed that the applied method choose a particle size reduction and transition to the pure _ form resulting in needle-shaped crystals, regardless of the chosen solvent. In order to identify which process was responsible for the above results, Piroxicam was further precipitated from the same three solvents by traditional evaporation method (RV-samples). The dissolution profiles of Piroxicam processed in SCO2 show a better dissolution performance of Piroxicam over their corresponding system obtained by traditional evaporation method