Spray drying egg using either maltodextrin or nopal mucilage as stabilizer agents.

In this work, a comparative study between spray drying (SD) of fresh egg by either maltodextrin (MD) or nopal-mucilage (MN) as stabilizing vectors was made. The powders obtained were characterized for drying performance, moisture content, chemical proximate analysis, thermal analysis (TGA), chemical composition (FTIR), microscopy (SEM) and rheology (viscoelasticity and steady state simple shear viscosity). Infrared analysis showed that MN has the effect of a thickening agent rather than an encapsulating one. Results indicated that SD egg with MN produced a high thermal and mechanical stable product and rendered the highest drying performance, producing a more uniform and defined sphere-shaped morphology in comparison to egg SD either alone and with MD.

Morphological and release characterization of nanoparticles formulated with poly (dl-lactide-co-glycolide) (PLGA) and lupeol: In vitro permeability and modulator effect on NF-κB in Caco-2 cell system stimulated with TNF-α.

Lupeol exhibits anti-inflammatory effects; unfortunately it shows low water solubility. An alternative to overcome this is the development of nanomaterials. Several methods for nanomaterial production are available. One of them is emulsification/solvent-evaporation. The objective of the present work was to evaluate physical properties, transport and in vitro modulator effects on NF-κB of poly (lactide-co-glycolide) (PLGA) nanoparticles loaded with lupeol. Nanonutraceuticals were prepared with 16% (w/v) of lupeol. Size distribution and morphology were measured by particle size analyzer and TEM. In vitro release of lupeol was studied by three different models: Higuchi, Siepmann & Peppas, and Power law. Transport of nanonutraceutical was studied in a Caco-2 cell model and by GC-MS. Modulator effect on NK-κB was studied by western blot analysis. Nanonutraceuticals were 10% larger than the nanoparticles without lupeol (372 vs 337 nm) and presented a broader size distribution (0.28 vs 0.22). TEM results displayed spherical structures with a broader size distribution. Entrapment efficiency of lupeol was 64.54% and it in vitro release data fitted well to the Power law and Higuchi equation (R > 0.84-0.84). Strong regulation of NF-κB of nanonutraceutical was observed. It was not observed any transport across the Caco-2 cell model at the different experimental conditions.

Characterization of physical interaction between Casiopeina III-ia and chitosan. Toward a Cas III-ia drug delivery system.

Casiopeínas are a new generation of anticancer drugs that have shown great in vitro and in vivo antineoplastic activities. Information about interaction drug-excipient, for developing a based-nanoparticle drug delivery system, has not been investigated yet. In order to elucidate if chitosan (CS) modifies the copper complex due to its interaction with Cu(2+) ion, different studies in aqueous media between CS and Casiopeina III-ia (Cas III-ia) were carried out. CS-Cas III-ia mixtures were characterized by viscosity curves, UV-vis, EPR, and in vivo activity against HeLa cell line. Rheological behavior showed a decrease of viscosity when the drug was present due to diminished electrostatic interactions of charged amine group. UV-vis results illustrate that Cas III-ia is not stable at low pH as a result of interaction with acetic acid. However, when chitosan is present at the acidic solution Cas III-ia is stable. These results are supported by EPR studies. Finally, activity of the drug against HeLa cell line was not modified. Therefore, the present work presents evidence that there is no breaking of copper complex due to interaction between CS and Cas III-ia in acidic media. In addition, Cas III-ia maintains both its stability and effectiveness against cancer cell line.

Influence of three different colloidal systems on the oxytetracycline-lecithin behavior.

Oxytetracycline (OTC) is a wide spectrum antibiotic, but it is known to be degradated when it is stored under adverse conditions. It is classified as short-acting based on serum half-lives of 6-8 h. The stabilizing effect of colloidal carrier systems and their ability to sustain drug release for OTC was investigated using solid dispersion, liposomes and solid lipid nanoparticles with lecithin. Analysis of chemical stability showed that OTC is more resistant in colloid systems than in the free form. The characterization results show clear differences between the prepared systems. Release studies show that a sustained release is achieved when the OTC is formulated in these carriers.

Histamine interaction with Zn2+ and Cu2+ porphyrins.

Histamine may be present in biological fluids and in pharmaceutical dosage forms such as antiallergenic agents; when in excess, it causes a disorder called histaminosis. Many techniques have been developed to determine the concentration of this compound but the application of such methods is complicated and laborious, requiring expensive equipment and long times. A better alternative is to design chemical sensors. In the work reported here, six metalloporphyrins (Cu2+ or Zn2+) with different peripheral groups - benzoate, tosylate and carboxylate - were studied. The stability constants for these compounds were determined with histamine at different temperatures. Histamine is strongly bound to metallic porphyrins containing Cu2+ and Zn2+; however, the binding force does not depend exclusively on the metal center. Stabilization of the complex is strongly influenced, in some cases, by the lateral chains of the porphyrin. This possibility implies that this system can be very selective for this biogenic amine.

Sustained availability of trimethoprim in drinking water to achieve higher plasma sulphonamide-trimethoprim antibacterial activity in broilers.

(1) In order to make trimethoprim (TMP) available to broilers throughout the day, a sustained release formulation (SRF) of the drug in the form of granules was added to the water tank that supplies drinking water. (2) Broilers were initially dosed with sulphachloropiridazine-TMP (SCP-TMP 5:1) and then further medicated throughout the day, achieving in the end a dose of 30 mg/kg each of SCP and TMP (group A). Group B received a preparation with the same dose of SCP and TMP (1:1) as group A, but administered as a single dose without the SRF of TMP. Group C received the customary SCP-TMP 5:1 preparation (30 and 6 mg/kg, respectively). Water tanks were completely consumed in 3 to 4 h. (3) Broilers were bled at different times and concentration of antibacterial activity in serum determined by correlating the composite antibacterial activity of SCP and TMP with actual concentrations of these drugs by means of a microbiological agar diffusion assay. (4) Time vs serum concentrations of activity were higher in group B; the increments in the maximum serum concentration for group B over groups A and C being 39 and 67%, respectively. (5) However, the sustained concentration of activity over time, measured as the area under the cu)rve, was highest in group A. Group B had higher values for area under the curve than group C. (6) An additional dose of TMP to achieve 30 mg/kg of both SCP and TMP improves the serum concentration of this combination over the customary 5:1 proportion. The best values for sustaining antibacterial activity were obtained using a 1:1 ratio as in group A. The use of a SRF as in group A may translate into better clinical results.

Study of the binding in an aqueous medium of inclusion complexes of several cyclodextrins involving fenoprofen calcium.

Interactions among fenoprofen calcium and alpha-, beta-, gamma- and hydroxypropyl-beta-cyclodextrins (HP-beta-CD) were evaluated in aqueous solution by UV/vis and fluorescence direct spectroscopies and monodimensional (1D) 1H-NMR. Different UV/vis and fluorescence emission spectra were obtained to study the apparent binding constants (K) to define the most appropriate cyclodextrin to form the inclusion complexes (IC). beta-CD and HP-beta-CD clearly fit the magnitude of stability constant data of the complexes to take into account the pharmaceutical technology interest.

Solubility, 1H-NMR, and molecular mechanics of mebendazole with different cyclodextrins.

The solubility behavior and binding constants (Kass) of mebendazole with alpha-, beta-, gamma-, and hydroxypropyl-beta-cyclodextrins (HP-beta-CD) have been investigated in simulated intestinal juice by the Higuchi and Connors method. AL diagrams have been obtained. The equilibrium has also been studied in simulated gastric fluid with HP-beta-CD. The phase solubility, 1H-NMR, and molecular mechanics studies revealed the formation of a 1:1 complex.

Binding, molecular mechanics, and thermodynamics of cyclodextrin inclusion complexes with ketoprofen in aqueous medium.

The purpose of this work was to study the interaction forces involved in the inclusion processes of ketoprofen with several cyclodextrins and to assess the best cyclodextrin for complexing this anti-inflammatory drug. The behavior of the inclusion complexes of ketoprofen with alpha-, beta-, and gamma-cyclodextrins was studied by UV-VIS direct spectroscopy, 1H NMR, and molecular mechanics. Thermodynamic parameters for the binding processes were obtained from the temperature variations in binding constants, which manifest that "nonclassical" hydrophobic interactions are the main forces involved in these inclusion processes. Binding constants show that beta- and gamma-cyclodextrins form more stable 1:1 complexes with ketoprofen than does alpha-cyclodextrin. 1H NMR spectra show that the inclusion degree depends on the size of the internal diameter of cyclodextrin. The geometries calculated on the bases of molecular mechanics for these three-dimensional models indicate high stability.

Complexation and solubility behavior of albendazole with some cyclodextrins.

The main purpose of this work was to study the albendazole-cyclodextrins complexation equilibrium and to propose a suitable excipient to improve the solubility behavior and dissolution rate of albendazole. The complexation of albendazole with four cyclodextrins, alpha-CD, beta-CD, gamma-CD, and hydroxypropylated (HP)-beta-CD, has been studied by using electronic absorption spectroscopy and molecular mechanics. The equilibrium was studied at pH 7.5 under various temperature conditions, and at pH 1.8 with HP-beta-CD at 298 K. The albendazole binding constant was the greatest for the HP-beta-CD. Both the un-ionized (Alb) and the ionized species (AlbH+) were shown to interact with HP-beta-CD. The studies at different temperatures suggest that the hydrophobic effect is the most important driving force in these systems. Moreover, the dissolution rate studies with beta- and HP-beta-CDs in the buffered aqueous solution at pH 7.5 have been accomplished and the dissolution rate was observed to increase with the cyclodextrin concentration. The solubility behavior was studied with the Higuchi and Connors method. The phase solubility and direct spectroscopy methods reveal a 1:1 inclusion complex in all of the studied cases. Molecular mechanics data show the most probable structure of the complexes.