Fábio Santos de Souza

Anxiolytic-like activity and GC–MS analysis of (R)-(+)-limonene fragrance, a natural compound found in foods and plants

The traditional use of essential oils in aromatherapy has offered numerous health benefits. However, few scientific studies have been conducted with these oils to confirm their therapeutic efficacy. (+)-Limonene is a chemical constituent of various bioactive essential oils. The present study reports on the anxiolytic-like effects of (+)-limonene in an elevated maze model of anxiety in mice. At concentrations of 0.5% and 1.0%, (+)-limonene, administered to mice by inhalation, significantly modified all the parameters evaluated in the elevated plus maze test. The pharmacological effect of inhaled (+)-limonene (1%) was not blocked by flumazenil. Analysis of (+)-limonene using gas chromatography-mass spectrometry (GC-MS) showed its volatility to be high. These data suggest possible connections between the volatility of (+)-limonene and its anxiolytic-like effect on the parameters evaluated in the elevated plus maze test. The data indicate that (+)-limonene could be used in aromatherapy as an antianxiety agent.

Studies of cimetidine pre-formulated and tablets for TG and DSC coupled to the photovisual system

Abstract This work studied the compatibility pre-formulated drug–excipient mixtures and tablets of cimetidine by TG and DSC coupled to a photovisualization system. The excipients PVPK30, explocel, microcel MC101, aerosil, and magnesium stearate were studied. Curves for the phase transitions of pre-formulated, microcel– and explocel–cimetidine were obtained. The results showed that the excipients, microcel and explocel, did not produce changes in the thermal behavior of cimetidine. This fact was confirmed by the DSC coupled photovisualization system. The rate constants for the thermal decomposition reaction were determined by an isothermal thermogravimetric (TG) method using the classical Arrhenius equations. The results showed that cimetidine tablets presented a stability higher than the cimetidine–excipient mixtures.

THERMAL AND DISSOLUTION KINETICS OF AMPICILLIN DRUG AND CAPSULES

This work aims to compare the thermal decomposition and dissolution kinetics of ampicillin drug and products A, B and C. The thermal decomposition reaction rate constants (kT) were determined by isothermal thermogravimetric method using the classical Arrhenius equations. The dissolution profiles were obtained using USP 23 method and rate constants (kD) were determined by Kitazawa equation. The results showed correlation between kT and kD can be used in the study of preformulation of drugs and also as a parameter in the studies of pharmaceutical equivalence.

Model Analytical Development for Physical, Chemical, and Biological Characterization of Momordica charantia Vegetable Drug

Momordica charantia is a species cultivated throughout the world and widely used in folk medicine, and its medicinal benefits are well documented, especially its pharmacological properties, including antimicrobial activities. Analytical methods have been used to aid in the characterization of compounds derived from plant drug extracts and their products. This paper developed a methodological model to evaluate the integrity of the vegetable drug M. charantia in different particle sizes, using different analytical methods. M. charantia was collected in the semiarid region of Paraíba, Brazil. The herbal medicine raw material derived from the leaves and fruits in different particle sizes was analyzed using thermoanalytical techniques as thermogravimetry (TG) and differential thermal analysis (DTA), pyrolysis coupled to gas chromatography/mass spectrometry (PYR-GC/MS), and nuclear magnetic resonance (1H NMR), in addition to the determination of antimicrobial activity. The different particle surface area among the samples was differentiated by the techniques. DTA and TG were used for assessing thermal and kinetic parameters and PYR-GC/MS was used for degradation products chromatographic identification through the pyrograms. The infusions obtained from the fruit and leaves of Momordica charantia presented antimicrobial activity.

Antifungal Activity of the Essential Oil of Cinnamomum zeylanicum Blume and Eugenol on Aspergillus flavus

Abstract The genus Aspergillus includes filamentary fungi that can cause diseases in humans and animals, being the most common forms of allergic bronchopulmonary aspergillosis, pulmonary aspergilloma and invasive aspergillosis. Furthermore, A. flavus can contaminate foods of plant origin and produce toxic metabolites to humans and animals such as aflatoxins. This research aims to study the antifungal potential of the essential oil from leaves of Cinnamomum zeylanicum and its major compound, eugenol, on Aspergillus flavus. Results showed that the essential oil showed 650 μg/mL MIC and 2600 μg/mL MFC, the eugenol in turn, presented 337.5 μg/mL MIC and 1350 μg/mL MFC. In evaluating the effect of oil and eugenol on conidial germination at all concentrations tested, the oil and eugenol inhibited the germination of fungal structures. In relation to the effects of the essential oil and eugenol on the morphology of A. flavus, it was clearly observed a reduction in hyphae pigmentation, number of conidiophores and inhibition of the conidiation process, which is the formation of conidia on the conidiophore head. Given these results, the essential oil of C. zeylanicum has great potential as possible alternative in the treatment of aspergillosis caused by A. flavus.