Optimized Chitosan-Based Nanoemulsion Improves Luteolin Release.

Luteolin (LUT) is a flavonoid found in several edible and medicinal plants. It is recognized for its biological activities such as antioxidant, anti-inflammatory, neuroprotective, and antitumor effects. However, the limited water solubility of LUT leads to poor absorption after oral administration. Nanoencapsulation may improve the solubility of LUT. Nanoemulsions (NE) were selected for the encapsulation of LUT due to their biodegradability, stability, and ability to control drug release. In this work, chitosan (Ch)-based NE was developed to encapsulate luteolin (NECh-LUT). A 23 factorial design was built to obtain a formulation with optimized amounts of oil, water, and surfactants. NECh-LUT showed a mean diameter of 67.5 nm, polydispersity index 0.174, zeta potential of +12.8 mV, and encapsulation efficiency of 85.49%. Transmission electron microscopy revealed spherical shape and rheological analysis verified the Newtonian behavior of NECh-LUT. SAXS technique confirmed the bimodal characteristic of NECh-LUT, while stability analysis confirmed NECh-LUT stability when stored at room temperature for up to 30 days. Finally, in vitro release studies showed LUT controlled release up to 72 h, indicating the promising potential of NECh-LUT to be used as novel therapeutic option to treat several disorders.

Study of the Effects of L-tryptophane Nanoparticles on Motor Behavior in Alzheimer's Experimental Models.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease characterized by the progressive and incapacitating decay of cognitive, neuropsychiatric, and behavioral manifestations. L-tryptophan is the precursor amino acid of serotonin, which is a neurotransmitter responsible for mood balance and the sense of well-being and can be administered in the form of nanoparticles. OBJECTIVE: This study analyzed the effectiveness of L-tryptophan nanoparticles and L-tryptophan on behavioral physiological alterations resulting from AD in animal models. METHODS: The sample consisted of 50 Rattus norvegicus rats, divided in 10 groups with 5 animals each: one negative control (NC), three positive control groups (C3, C7, and C21), three groups treated with L-tryptophan nanoparticles (T3N, T7N, and T21N) at the concentration of 1.5 mg, and three groups treated with L-tryptophan (T3L, T7L, and T21L) at the concentration of 1.5 mg. The rats underwent stereotactic surgery to induce AD through the injection of amyloid beta-amyloid peptide1-42 in the intracerebroventricular region. All rats were submitted to pre- and post-surgery and post-treatment motor behavior evaluation through the Later Water Maze (LWM) and elevated cross-labyrinth (ECL). Histological analysis was performed to verify the presence of senile plaques, and the statistical analysis used the unpaired T-test. RESULTS: Significant intergroup differences were observed in some of the evaluated parameters between treated and untreated groups. CONCLUSION: It was concluded that the treatment with L-tryptophan nanoparticles was beneficial to improve behavioral reactions in the Alzheimer's model.

Reversed phase HPLC determination of zidovudine in rat plasma and its pharmacokinetics after a single intranasal dose administration.

The development and validation of a simple and accurate method based on HPLC with ultraviolet detection for the quantification of zidovudine in rat plasma and its application to a pharmacokinetic study following a single intranasal dose zidovudine is described. Zidovudine was extracted from the plasma using a single-step deproteinization. Chromatographic separation of zidovudine from interfering components was achieved with a C-18 reverse phase column, a mobile phase consisting of a mixture of sodium acetate buffer (55 mM) with pH adjusted to 7.0 and acetonitrile (91:9 v/v) and UV detection set at 265 nm. The method was linear from 100 to 10,000 ng.mL(-1) (r(2) > or = 0.9995), and zidovudine had a mean recovery from plasma of 92.8%. The coefficient of variation of inter-day and intra-day quality control samples was less than 15%. After a single intranasal dose of zidovudine administered to rats, pharmacokinetic parameters (AUC(0-24), C(max), t(max), t(1/2)) were determined. The proposed method was found to be simple, specific, accurate, and precise and could be applied to the quantitative analysis of clinical pharmacokinetic studies of zidovudine in rats.

Reversed phase HPLC determination of zidovudine in rat plasma and its pharmacokinetics after a single intranasal dose administration

The development and validation of a simple and accurate method based on HPLC with ultraviolet detection for the quantification of zidovudine in rat plasma and its application to a pharmacokinetic study following a single intranasal dose zidovudine is described. Zidovudine was extracted from the plasma using a single-step deproteinization. Chromatographic separation of zidovudine from interfering components was achieved with a C-18 reverse phase column, a mobile phase consisting of a mixture of sodium acetate buffer (55mM) with pH adjusted to 7.0 and acetonitrile (91:9 v/v) and UV detection set at 265 nm. The method was linear from 100 to 10000 ng.mL"¹ (r² > 0.9995), and zidovudine had a mean recovery from plasma of 92.8 percent. The coefficient of variation of inter-day and intra-day quality control samples was less than 15 percent. After a single intranasal dose of zidovudine administered to rats, pharmacokinetic parameters (AUC0 24, Cmax, t , t1/2) were determined. The proposed method was found to be simple, specific, accurate, and precise and could be applied to the quantitative analysis of clinical pharmacokinetic studies of zidovudine in rats.

PLGA nanoparticles containing praziquantel: effect of formulation variables on size distribution.

Praziquantel has been shown to be highly effective against all known species of Schistosoma infecting humans. Spherical nanoparticulate drug carriers made of poly(D,L-lactide-co-glycolide) acid with controlled size were designed. Praziquantel, a hydrophobic molecule, was entrapped into the nanoparticles with theoretical loading varying from 10 to 30% (w/w). This study investigates the effects of some process variables on the size distribution of nanoparticles prepared by emulsion-solvent evaporation method. The results show that sonication time, PLGA and drug amounts, PVA concentration, ratio between aqueous and organic phases, and the method of solvent evaporation have a significant influence on size distribution of the nanoparticles.

Drug delivery systems: past, present, and future.

Drug delivery systems are essential components of drugs controlled release. In the last decades, several drug delivery technologies have emerged including capsules, liposomes, microparticles, nanoparticles, and polymers. These components must be biocompatible, biodegradable, and display a desired biodistribution providing a long-term availability of the therapeutic at specific target over time.