Julio César Rivera-Leyva

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In vitro dissolution studies for solid oral dosage forms have recently widened the scope to a variety of special dosage forms such as suspensions. For class II drugs, like Ibuprofen, it is very important to have discriminative methods for different formulations in physiological conditions of the gastrointestinal tract, which will identify different problems(More)
4-Nitro-N-(5-nitro-1,3-thiazol-2-yl)benzamide (1), a new nitazoxanide analog, was synthesized; its chemical structure was confirmed by 1H, 13C NMR, and HRMS. In this study, we evaluated the in vitro activity of compound 1 against Giardia lamblia trophozoites, as well as its in vivo giardicidal activity in a CD-1 mouse model. A pharmacokinetic study in(More)
OBJECTIVES The aim was to evaluate the relaxant effect of extracts from Valeriana edulis and determine the possible mechanism of action of the hexanic extract as vasorelaxant agent. METHODS Extracts from rhizomes obtained by maceration (hexanic (HEVe), dichloromethanic (DEVe), methanolic (MEVe) and hydroalcoholic (HAEVe) (3.03-500 microg/ml)) were(More)
ETHNOPHARMACOLOGICAL RELEVANCE To optimize the obtention of tilianin, an antihypertensive flavonoid isolated from Agastache mexicana (Lamiaceae), a medicinal plant used in Mexico for the treatment of hypertension. Also, a validated HPLC method to quantify tilianin from different extracts, obtained by several extraction methods, was developed. MATERIALS(More)
A series of 1H-benzo[d]imidazole analogues of Pimobendan, substituted at position 5 with either -CF(3) or -NO(2), were synthesized using a short synthetic route. All the nitro derivatives were potent, and exhibited a concentration- and partial endothelium-dependent vasorelaxant effects, with EC(50)s <5microM.(More)
RMELanc-induced relaxation in aortic rings precontracted with NE, 5-HT and KCl. It also reduced NE-induced transient contraction in Ca(2+)-free solution and inhibited contraction induced by increasing external calcium. Nevertheless, the vasorelaxant effect of RMELanc was not reduced by ODQ, 1-alprenolol, TEA, glibenclamide, and 2-AP. Oral administration of(More)
The low oral bioavailability of drugs can be principally attributed to their low solubility, low permeability, and low dissolution rate in the gastrointestinal tract. Considering the low lab-to-market success rate, it is highly important to evaluate these bioavailability factors in the early stages of drug discovery and development. In this work, some(More)
Lead exposure induces DNA damage, oxidative stress, and apoptosis, and alters DNA repair. We investigated the effects of melatonin co-administered to rats during exposure to lead. Three doses of lead acetate (10, 50 and 100mg/kg/day) were administered to rats during a 6-week period. Lymphocytes were analyzed. Lead exposure decreased glutathione (GSH) levels(More)
In the current investigation, the physicochemical, biopharmaceutical and pharmacokinetic characterization of a new clofibric acid analog (Compound 1) was evaluated. Compound 1 showed affinity by lipophilic phase in 1 to 5 pH interval, indicating that this compound would be absorbed favorably in duodenum or jejunum. Also, Compound 1 possess two ionic(More)
Stansin 6 a tetrasaccharide resin glycoside isolated from the root of Ipomoea stans was evaluated as anticonvulsant and neuroprotective in kainic acid-induced seizures of rats. Intraperitoneal injection of kainic acid (10 mg/kg) induced typical behavioral seizures such as wet dog shakes and limbic seizures, and histopathological changes in the hippocampus(More)
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