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Papers by Inés Fuentes-noriega

Proceedings of the Western Pharmacology Society

Tacrolimus is a macrolide immunosuppressant that is safe and effective for the prevention of reje... more Tacrolimus is a macrolide immunosuppressant that is safe and effective for the prevention of rejection after kidney transplantation. The oral bioavailability of tacrolimus averages 20% to 25%; however, the inter-individual variability in this parameter is large. Because of the poor correlation of dose to blood concentration between patients, the variability in pharmacokinetics and a relatively narrow therapeutic window, therapeutic drug monitoring of tacrolimus trough whole blood concentrations must be a standard practice. The objective of this evaluation was to determine the relationship among changes in hematocrit, albumin, and corticosteroid dosing on the disposition of tacrolimus during 6 months of treatment in renal transplant recipients. Blood samples for the determination of trough tacrolimus concentrations were taken immediately prior to the morning dose, samples were collected according to the request of the attending physician. Clinical and dosage data were reviewed 6 mont...

Journal of the Mexican Chemical Society

Journal of Bioanalysis & Biomedicine, 2010

ABSTRACT Casiopeína IIgly is a mixed chelate coordination complex with copper core that have demo... more ABSTRACT Casiopeína IIgly is a mixed chelate coordination complex with copper core that have demonstrated high antineoplastic activity in vitro and in vivo .In the present work, a developed and validated method for measurement of Casiopeína IIgly in beagle dog and its application in a pharmacokinetic study is reported. The analyte was isolated from blood by solid-phase extraction using Strata X cartridges. The analysis was carried out on a Synergy Polar-RP column (30 X 2.0 mm) using an isocratic elution and MeOH/ HFBA 0.1% (4:6) as the mobile phase. An Agilent LC/ MSD Trap VL equipped with an ionization electrospray source, was operated in selective ion storage (SIS) using stable ion [Cu(II) (F7C3COO) 4,7-dimethyl phen ]+ result of ESI reaction between Casiopeína IIgly and HFBA. The method demonstrated to be linear (r = 0.9992) in the range from the 0.1 to 15 μg/ml with a limit of detection (LOD) of 50 ng/ml. All the parameters of validation such as selectivity, accuracy, precision and recovery were within the required limits. Pharmacokinetics assay was carried out at 2 doses, indicated a high elimination rate.

Checkpoint kinase Chk1 is constitutively active in many cancer cell types and new generation Chk1... more Checkpoint kinase Chk1 is constitutively active in many cancer cell types and new generation Chk1 inhibitors show marked antitumor activity as single agents. Here we present a hitherto unrecognized mechanism that contributes to the response of cancer cells to Chk1-targeted therapy. Inhibiting chronic Chk1 activity in cancer cells induced the tumor suppressor activity of protein phosphatase protein phosphatase 2A (PP2A), which by dephosphorylating MYC serine 62, inhibited MYC activity and impaired cancer cell survival. Mechanistic investigations revealed that Chk1 inhibition activated PP2A by decreasing the transcription of cancerous inhibitor of PP2A (CIP2A), a chief inhibitor of PP2A activity. Inhibition of cancer cell clonogenicity by Chk1 inhibition could be rescued in vitro either by exogenous expression of CIP2A or by blocking the CIP2A-regulated PP2A complex. Chk1-mediated CIP2A regulation was extended in tumor models dependent on either Chk1 or CIP2A. The clinical relevance of CIP2A as a Chk1 effector protein was validated in several human cancer types, including neuroblastoma, where CIP2A was identified as an NMYC-independent prognostic factor. Because the Chk1-CIP2A-PP2A pathway is driven by DNA-PK activity, functioning regardless of p53 or ATM/ATR status, our results offer explanative power for understanding how Chk1 inhibitors mediate single-agent anticancer efficacy. Furthermore, they define CIP2A-PP2A status in cancer cells as a pharmacodynamic marker for their response to Chk1-targeted therapy. Cancer Res; 73(22); 6757-69. Ó2013 AACR.

Journal of Pharmacy and Pharmacology, 1998

In several studies of patients with neurocysticercosis under treatment with albendazole the pharm... more In several studies of patients with neurocysticercosis under treatment with albendazole the pharmacokinetic data were difficult to interpret, probably because of slow and erratic drug dissolution response and absorption problems in-vivo. Because there is no information available about the physicochemical properties of the drug, the aim of this work was to explain this erratic behaviour by fully characterizing the solution behaviour of the drug and its metabolite. To accomplish this, the physicochemical properties, pKa and solubility, and in-vitro plasma binding of albendazole and its main metabolite, albendazole sulphoxide, were studied by conventional methods. The intestinal and gastric absorption and dissolution behaviour of albendazole were also studied.

Biopharmaceutics & Drug Disposition, 1997

The distribution of 10-hydroxy carbazepine (MHD), the main metabolite of oxcarbazepine (OXC), was... more The distribution of 10-hydroxy carbazepine (MHD), the main metabolite of oxcarbazepine (OXC), was investigated in plasma and red cells. After the oral administration of 600mg of OXC to nine healthy volunteers, blood samples were withdrawn for the next 56h and packed red cells were separated from plasma by centrifugation. Also, in vitro studies of plasma binding of MHD were carried out by a dialysis technique. Results showed that the in vitro protein binding was low. The mean bound concentration ranged from 37 to 40%; however, an affinity of MHD to red corpuscles was found. These observations indicate that MHD red blood cell concentrations together with plasma measurements could be useful in cases of inefficacy or toxicity in order to make the appropriate drug adjustments.

Biomedical and Pharmacology Journal, 2015

Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, Jan 5, 2003

A sensitive and specific liquid chromatographic method using solid-phase extraction with Sep-pak ... more A sensitive and specific liquid chromatographic method using solid-phase extraction with Sep-pak cartridges has been developed for the determination of Casiopeina IIgly and validated over the linear range 2.5-50 microg/ml in rat plasma. The analysis was performed on a Symetry C(18) (5 microm) column with a Phenomenex C(18) precolumn. The mobile phase was methanol-water (58:42, v/v). The column effluent was monitored at 273 nm. The results showed that the assay is sensitive at 2.5 microg/ml. Maximum intra-day coefficient of variation was 11.47%. The recovery based upon addition of internal standard to rat plasma was 80.98%. The method was used to perform preclinical pharmacokinetic studies in rat plasma and was found to be satisfactory.

Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, Jan 25, 2002

A sensitive and specific liquid chromatographic method using extraction with zinc sulfate has bee... more A sensitive and specific liquid chromatographic method using extraction with zinc sulfate has been developed for the determination of Casiopeina IIIi and validated over the linear range 5-100 microg/ml in 1 ml of rat plasma. The analysis was performed on a Symmetry C(18) (5 microm) column. The mobile phase was methanol: 0.01 M phosphate buffer pH 6.5 (40:60, v/v). The column effluent was monitored at 262 nm. The results showed that the assay is sensitive at 5 microg/ml. Maximum intra-day coefficient of variation was 10.6%. The recovery obtained in plasma was 87.2%. The method was used to perform protein binding studies by equilibrium dialysis in rat plasma and was found to be satisfactory.

A quantitative method for the simultaneous determination of docetaxel (Taxotere), paclitaxel (Tax... more A quantitative method for the simultaneous determination of docetaxel (Taxotere), paclitaxel (Taxol), 6r-hydroxypaclitaxel, and p-3′-hydroxypaclitaxel in human plasma and oral fluid is developed and validated. Oral fluid (this term is now preferred to saliva) was sampled with a Salivette collection device. The procedure used a simple liquid/liquid extraction with methyl tert-butyl ether followed by LC-ESI-MS/MS. Gradient elution was applied and provided increased robustness to ion suppression by the drug formulation vehicle (polysorbate 80 and Cremophor EL). Adduct ion formation with sodium and potassium was noticed and controlled by mobile-phase optimization. The protonated analytes generated in the positive ion mode were monitored through multiple reaction monitoring. Calibration was performed by internal standardization with cephalomannine, and regression curves were constructed ranging between 2 and 1000 ng/mL in plasma and 0.125 and 62.5 ng/mL in oral fluid, using a weighing factor of 1/x 2 . The regression curves were quadratic for paclitaxel and docetaxel and linear for the paclitaxel metabolites. Accuracy varied from 91.3 to 103.6%, and imprecision did not exceed 12.7% for all analytes in plasma and oral fluid. In conclusion, a sensitive and robust method was obtained, which fulfilled all validation criteria.

International journal of pharmaceutics, 2007

Benzimidazole 2-carbamates, such as albendazole (ABZ) and mebendazole (MBZ), used for the treatme... more Benzimidazole 2-carbamates, such as albendazole (ABZ) and mebendazole (MBZ), used for the treatment of helmintic infections, have low aqueous solubility and poor bioavailability, both of which lead to high interindividual variability when used for human systemic helmintiosis; therefore, it is necessary to search for new anthelmintics with better biopharmaceutical properties. In the present study the solubility, pKa, logP and apparent permeability in the Caco-2 cells system of four novel anthelmintic (1H-benzimidazol-5(6)-yl)carboxamide derivatives (compounds 1-4) with a 2-methylthyo group were evaluated. Also the pharmacokinetic parameters of compound 1 which in previous studies showed activity similar to ABZ against T. spirallis, was evaluated in BALB/c mice, as a representative molecule of the series. The novel anthelmintics, showed better solubility than ABZ in aqueous acid pH and in organic solvents. The logP, P(app) and Caco-2 data indicate that the 4 derivatives are highly per...