Brewing effect on levels of biogenic amines in different coffee samples as determined by LC-UV.

Eight biogenic amines (spermine, spermidine, putrescine, histamine, tyramine, phenylethylamine, cadaverine and serotonin) were determined by LC-UV after derivatization with dansyl-chloride in both ground coffee and coffee beverages obtained by different methods. In ground coffee, the most relevant amine was PUT, followed by SPD, HIS, TYR, CAD, SPM, PHE, and SER, with the total BAs content decreasing as the roasting degree increased. In coffee brews, the order was PUT, SPM, TYR, CAD, SPD, PHE, HIS, and SER, but at a very low level in comparison with the amount of BAs determined in roasted ground coffee. Beverages prepared by espresso, capsule, and pod machines had the lowest BAs contents, as a result of the thermal and physical stress imposed on ground coffee by these methods, while mocha contained the highest BAs amounts owing to lower pressure and longer brewing time.

Co-encapsulation of antioxidants into niosomal carriers: gastrointestinal release studies for nutraceutical applications.

Recently niosomes have been used as nutraceutical vehicles of functional components, useful in the prevention of many diseases caused by oxidative stress, with the aim to control their delivery into the body and to increase the nutritional quality of food dairy products with which these products can be enriched. We decided to develop novel niosomal formulations containing nutritional supplements such as gallic acid, ascorbic acid, curcumin and quercetin as single agents and in combination, to evaluate the effect of the active molecules co-encapsulation on the physico-chemical properties of the carriers, on their antioxidant properties and capability of releasing the encapsulated materials. Results suggest that the co-encapsulations of gallic acid/curcumin and ascorbic acid/quercetin mix influence their physico-chemical properties and their entrapment efficiencies respect to the formulations containing the single antioxidant; also the antioxidants releases appeared to improve and their combinations resulted in a promoted ability of reducing free radicals, due to a synergic antioxidant action.

Respirable rifampicin-based microspheres containing isoniazid for tuberculosis treatment.

The purpose of this investigation was to develop small microspheres for delivering antimycobacterial drugs to infected host macrophages. Rifampicin-based microparticles were prepared. The drug was covalently linked to acrylic moieties to obtain a polymerizable derivative for the preparation of materials useful as drug delivery systems that then were loaded with isoniazid acting in synergy with rifampicin. Their antitubercular activity was determined in vitro. Fourier transform infrared spectroscopy confirmed hydrogel structure. Morphological analysis showed microparticles with spherical shape and homogeneous surface. In vitro release studies were performed in media simulating physiologic pH (7.4) and endosomal of alveolar macrophages pH (5.2). A similar amount of isoniazid was delivered within the first 6 h at both pHs, while a smaller amount of the drug was delivered at pH 7.4 in the last phase of the study. In vitro antitubercular activity showed a behavior comparable to that of rifampicin and isoniazid free. Bioactive swelling matrices, showing a high swelling degree into a medium miming intra alveolar environment, were obtained. They could be applied for their antitubercular activity.

A new approach for the evaluation of niosomes as effective transdermal drug delivery systems.

The central motivation for this study was to evaluate if the increased hydrophilic drug permeation across the skin, which is always observed in presence of vesicular systems, is dependent on the structural organization of niosomes, that are used to transport the active molecules, or if it is only dependent on the surfactant dual nature. To answer this question, non-ionic surfactants belonging to the class of Pluronic and sucrose esters were used both as components of niosomal systems or in the form of sub-micellar solutions. The obtained niosomes were characterized by their entrapment efficiency, size and morphology. The enhancing effect of niosomes on the ex vivo percutaneous penetration of a model drug was investigated using a Franz-type diffusion chamber and compared to that obtained by using sub-micellar solution of surfactant or achieving pretreatment of the skin with surfactants' sub-micellar solution or empty niosomes. The results suggest that the surfactants used in this study could be considered as percutaneous permeation enhancers only when they are in the form of drug-loaded vesicular systems: no percutaneous promotion was achieved by using sub-micellar solution containing free Sulfadiazine sodium salt or performing pretreatment with empty niosomes or sub-micellar solutions of the surfactant. In our experiments, only niosomes act as effective transdermal drug delivery systems.

Antioxidant activity of a Mediterranean food product: "fig syrup".

In this work, the efficacy of fig syrup, a Mediterranean fig derivative, as a nutraceutical supplement, was demonstrated. Fig syrup is a fruit concentrate used as a common ingredient in the preparation of typical foods, and particularly in cakes. In vitro assays were performed to determine the amount of nutraceutical ingredients, such as phenolic compounds (3.92 mg equivalent of gallic acid per g) and flavonoids (0.35 mg equivalent of catechin per g), while HPLC analyses provided specific information about the composition of antioxidants in the syrup. Furthermore, total antioxidant activity, scavenging properties against DPPH and peroxyl radicals, and the anticholinesterase activity, clearly showed the efficacy of the syrup in preventing damage induced by free radicals and, thus, the applicability of this food derivative as a nutraceutical supplement.

Selective determination of melamine in aqueous medium by molecularly imprinted solid phase extraction.

A molecularly imprinted polymer able to recognize melamine in partially aqueous medium was synthesized using methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linking agent. The bound specificity and selectivity of the obtained material were verified by performing binding experiments with melamine and its structural analogue, 2,4,6-trimethoxy-1,3,5-triazine, respectively, using different aqueous binding media. Finally, the ability of MIP to selectively extract melamine from two real samples, a food supplement and a freeze-dried meat sample, was demonstrated.

Molecularly imprinted polymers as drug delivery systems for the sustained release of glycyrrhizic acid.

OBJECTIVES: The aim was to synthesize molecularly imprinted polymers (MIPs) with high recognition properties towards glycyrrhizic acid and to evaluate the performance of these materials to act as base excipients in glycyrrhizic acid sustained release in gastrointestinal simulating fluids. METHODS: MIPs were synthesized using methacrylic acid (MAA) as acidic, 2-(dimethylamino)ethyl methacrylate (DMAEMA) as basic, and 2-hydroxyethylmethacrylate (HEMA) as neutral functional monomers, while ethylene glycol dimethacrylate (EGDMA) was chosen as a crosslinking agent. The imprinting effect was evaluated by binding experiments using glycyrrhizic acid and glycyrrhetic acid (analogue molecule) solutions and in-vitro release studies were performed in gastrointestinal simulating fluids. KEY FINDINGS: Good recognition and selectivity properties were found in all the synthesized materials in both ethanol and ethanol-water mixture. The release from non-imprinted polymers was indeed higher at acidic pH, while a slower release was observed in MIPs' case, because of the presence of imprinted cavities in the polymeric structure. The stronger capacity of MAA to interact by hydrogen bonds with the template makes MAA-containing MIPs the most effective materials in both rebinding and release experiments. CONCLUSIONS: The release tests confirm the applicability of imprinted polymer for glycyrrhizic acid sustained release in gastrointestinal simulating fluids.

Molecularly imprinted polymers for 5-fluorouracil release in biological fluids.

The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs) as a controlled release device for 5-fluorouracil (5-FU) in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs). MIPs were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

In vitro and in vivo evaluation of Bola-surfactant containing niosomes for transdermal delivery.

A novel niosome formulation is proposed for topical drug delivery of ammonium glycyrrhizinate, a natural compound with an efficacious anti-inflammatory activity. Niosomes were made up of a new non ionic surfactant, alpha,omega-hexadecyl-bis-(1-aza-18-crown-6) (Bola-surfactant)-Span 80-cholesterol (2:3:1 molar ratio). Niosome vesicles were prepared with the thin layer evaporation method and were physico-chemically characterized. The tolerability of Bola-surfactant both as free molecules or assembled ion niosome vesicles was evaluated in vitro on cultured of human keratinocyte cells (NCTC2544). Human tolerability was evaluated on volunteers. The ability of Bola-niosomes to promote intracellular delivery was evaluated by confocal laser scanning microscopy (CLSM) studies. Human stratum corneum and epidermis (SCE) membranes were used in vitro to investigate the percutaneous permeation. The anti-inflammatory activity of ammonium glycyrrhizinate was evaluated in vivo on human volunteers with a chemically induced erythema. Experimental data show that Bola-niosomes are characterized by a mean size of approximately 400 nm and are able to provide an encapsulation efficiency of 40% with respect to the drug amount used during preparation. CLSM showed that Bola-niosomes were able to promote the intracellular uptake of the delivered substances. Bola-niosomes were also able to significantly improve (p<0.001) the percutaneous permeation of ammonium glycyrrhizinate with respect to both the aqueous drug solution and a physical mixture between unloaded Bola-niosomes and the aqueous drug solution. Bola-niosomes showed a suitable tolerability both in vitro and in vivo. Ammonium glycyrrhizinate-loaded Bola-niosomes determined a significant (p<0.001) and noticeable improvement of the in vivo anti-inflammatory activity of the drug. An effective example of conjugating innovative colloidal carriers, coming from pharmaceutical nanotechnology, and therapeutically effective natural compounds, coming from traditional medicine, was reported.