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M L Sayalero

Publications and source records attributed to M L Sayalero.

5 recordsLinked to original sources
PubMed1999

High-performance liquid chromatographic validated assay of doxorubicin in rat plasma and tissues.

A specific and selective high-performance liquid chromatography (HPLC) technique that requires few manipulations, and is readily adaptable to analysis for a large series of samples, has been developed for the determination of the concentration of the anticancer drug doxorubicin (DXR) in rat serum and tissues. The biological samples were efficiently deproteinised and resolved from a reversed-phase nucleosil C18 column with fluorescence detection. The validation study of the proposed method was successfully carried out in an assay range of between 5 and 5000 ng/ml and was subsequently implemented in a pharmacokinetic study of DXR in Wistar rats that were treated by intravenous administration of the drug.

Animals↗
PubMed1992

A computer program (DCN) for numerical convolution and deconvolution of pharmacokinetic functions.

A program adapted for use on microcomputers (DCN) has been developed which permits one to perform operations of numerical convolution and deconvolution using polyexponential functions, that are often implemented in pharmacokinetic analysis. The program is written in Microsoft GWBASIC and can be used in personal computers with no modification. The user supplies information relating to the coefficients and exponentials defining the polyexponential equation of the response and weighting functions and the program performs the deconvolution operation by numerical integration using trapezoidal rule and provides numerical and graphic information concerning the input function. The program can be applied to the deconvolution of many linear pharmacokinetic systems and allows one to solve problems related to drug release, absorption, distribution, as well as others. Additionally, the program is able to perform the convolution operation if information about the input and weighting functions and is also able to simulate pharmacokinetic processes. The efficacy of the program was evaluated by comparison with several deconvolution algorithms, in particular that proposed by Veng-Pedersen and Iga.

Algorithms↗
PubMed1991

Bioequivalence of a new formulation of flecainide acetate.

A bioequivalence study was performed on a new formulation of flecainide acetate in 100 mg tablets, using a formulation of the same drug already commercialized and in use and at the same dose. The study was conducted with a cross-over assay in 10 healthy volunteers at a single oral dose of 200 mg (two tablets). The parameters obtained according to the model employed, with both formulations studied, showed a considerable degree of between-subject variability. The parameters showing the highest between-subject variability were Ka (VC: 80.5 and 166.8%; tmax, VC: 40.8 and 48.0%, and Ke, VC: 39.4 and 35.1%) for formulations A and B, respectively, the parameter with the least variability being the MRT (VC 18.7 and 21.7%) for formulations A and B. Statistical analysis of the parameters characterizing the rate and extent to which the drug accesses to the systemic circulation, by application of statistical tests conventionally used in this kind of study- the "t" tests and ANOVA-revealed that there were no statistically significant differences among the parameters defining these processes for either formulation studied, thus permitting the assumption of bioequivalence between both formulations. The results obtained by application of the criteria of superposition and statistical moments show that there are no statistically significant differences with respect to the fraction of the dose of flecainide administered that reaches the systemic circulation after administration of the two tablet forms studied, both containing 100 mg of active principle (dose: 2 x 100 mg).

Adult↗
PubMedDate not supplied

Pharmacokinetic and nephrotoxic study of gentamicin in rabbits using a new dosage regimen.

Currently, in certain clinical situations there is an increasing trend towards using dosage regimens involving aminoglycoside antibiotics based on the administration of a single dose of the drug per day instead of administering the same amount in two or three administrations. The aim of the present study was to discover the pharmacokinetic profile and the nephrotoxic potential of this new form of administration in experimental animals receiving gentamicin. The study was conducted on two groups of rabbits, one of which received a single dose of the drug at 7 mg/kg i.v. and the other 7 mg/kg administered every 12 hours, allometrically equivalent to gentamicin dosing at 5 mg/kg every 24 hours to human subjects. The number of doses administered was 20. From the pharmacokinetic point of view, the results point to the existence of a significant degree of accumulation of the antibiotic in renal cortex as a result of the dosage regimen, no important modifications occurring in the pharmacokinetic parameters of gentamicin calculated from its plasma kinetics. This shows that the two compartment model employed predicts drug levels in accessible tissues but not in deep ones where gentamicin is accumulated for long periods of time. From the toxicological point of view, the treatment caused appreciable damage of the renal tubules during the first phases of the treatment which was not detectable from the serum creatinine levels or the kinetic behaviour of the aminoglycoside.

Animals↗