[Application of the manova (multivariate analysis of variance) of statistical moments in a study of the bioavailability of 3 paracetamol formulations].
Explore the source record for details and available documents.
Acetaminophen↗
Biomedical subjects
M Llabrés
Publications and source records attributed to M Llabrés.
Quantification of the effect of excipients on bioavailability by means of response surfaces I: Amoxicillin in fat matrix.
A study was carried out to determine the effect of a fat excipient on the bioavailability of amoxicillin tablets. Three formulations with a fat excipient content of 10, 20, and 30%, respectively, were administered to 15 healthy volunteers according to a Latin-square design. The excretion curves were characterized with the help of two parameters, namely, the quantity of drug excreted between 0-2 and 0-12 hr postadministration, respectively. The effect of the fat excipient content was quantified with the use of polynomials whose corresponding orders were given by the ANOVA. In the case of both parameters, a quadratic response to the fat excipient content was found. At the same time, a dissolution study was carried out using a previously established method. Here, the parameters used to characterize the dissolution curves were the quantities of dissolved drug in 30 and 180 min, respectively. Again, a quadratic response to the fat excipient content was observed in the case of both parameters.
Adult↗
Quantification of the effect of excipients on bioavailability by means of response surfaces II: Amoxicillin in fat-silica matrix.
This report studies the bioavailability of amoxicillin in different fat-silica matrixes. A urinary excretion study was carried out on four formulations containing fat and silica excipients. The formulations were administered to 24 healthy volunteers according to a Latin-square design. The following percent proportions of fat-silica were used: 15:3.75, 15:7.50, 30:3.75, and 30:7.50. The urinary excretion curves were characterized using the quantity of unchanged drug excreted between 0-2 and 0-12 hr postadministration, respectively as parameters. The ANOVA results showed that both excipients had an additive effect on the quantity of drug excreted between 0 and 2 hr, whereas the effect on the quantity of drug excreted between 0 and 12 hr was also one of interaction between both excipients. Quantification of the ANOVA results in terms of excipient content was conducted by means of the adequate linear functions. At the same time, a dissolution study was carried out using the quantity of drug dissolved in 30 and 180 min as parameters. The behavior was similar to that encountered for the in vivo parameters.
Adolescent↗
Quantification of the effect of excipients on bioavailability by means of response surfaces III: In vivo--in vitro correlations.
This study compares one of the previously studied formulations with commercial amoxicillin capsules. The results indicate that the percentage of the dose absorbed is similar in both formulations; nevertheless, the amoxicillin capsules present a higher absorption rate. The in vivo--in vitro correlations in terms of response surfaces, and the general correlation among all the formulations studied in the three articles of this series is discussed. The quantity of drug excreted in 2 hr and the quantity of drug dissolved in 30 min presents a correlation coefficient r = 0.9458 (p less than 0.01) and the quantity of amoxicillin excreted in 12 hr and the quantity dissolved in 180 min presents a correlation coefficient r = 0.9761 (p less than 0.01).
Adolescent↗
[Oral bioavailability of cefadroxil: influence of food].
Explore the source record for details and available documents.
Administration, Oral↗
MANOVA of statistical moments in biopharmaceutical studies: a numerical example with three equally spaced doses of amoxicillin.
To assess the applicability of statistical moments in biopharmacuetical studies, an urinary excretion trial was conducted with three doses--400, 500, and 600 mg of amoxicillin trihidrate capsules--in 15 healthy volunteers, using a latin square design. The statistical analyses were a two-way MANOVA and a growth curve technique. It was inferred, in the dose range studied, that the amount excreted during the 12 hr following administration, was proportional to dose and that the dose had no effect on either the mean or the variance of the residence time. The calculated minimum significant difference in the amount of amoxicillin excreted was 15% with respect to the mean value.
Absorption↗
[Calculation of the dissolution velocity in systems without fluid recirculation or accumulating reservoir].
Explore the source record for details and available documents.
Biopharmaceutics↗
Comparative degradation study of biodegradable microspheres of poly(DL-lactide-co-glycolide) with poly(ethyleneglycol) derivates.
The biodegradable polymers of poly(DL-lactide-co-glycolide) (PLGA) and poly(ethyleneglycol) (PEG) have come into use in the last few years for the control of the release of drugs. The incorporation of units of PEG produce an increased in vivo half life of the microparticles. The methoxylation of the PEG allows a control of the microparticles. The methoxylation of the PEG allows a control of the polymerization reaction by blocking one of the reactive terminals. An important aspect to be studied is the degradation of these polymers. The objective was centred on comparing the degradation that microspheres made of PLGA and PLGA-PEG (also with derivate methoxylated PEG). Degradation of the microspheres was studied at 37 degrees C and neutral pH. Samples were taken at different times to determine the size distributions, the mean diameter, the molecular weight and the structural composition of the polymer. The fastest decrease in Mw is observed in the case of PLGA microspheres. The PLGA-PEG microspheres show a significant size increase (from 24.6 to 90 microns) due to a swelling process. Any appreciable changes in Tg values were observed during the assay (30 days).
Biocompatible Materials↗
The statistical interpretation of accelerated degradation studies in solutions.
Explore the source record for details and available documents.
Chemistry, Pharmaceutical↗
[The bioavailability of drugs administered via a minimal jejunostomy catheter. A clinico-experimental study].
For the evaluation of the bioavailability of drugs administered through a minimal jejunostomy catheter (MJC) postoperatively, ampicillin and metronidazol were administered via this route. The study with ampicillin consisted of a first cross-over experimental trial, in which six dogs were used, and a second based on the experience with four human volunteers. As a measure of the absorption of the drug, the serum levels of the lower plasma area are monitored. The statistical analysis was done by means of logarithmic transformation of the areas, and two-way analysis of variance. The posterior distribution of the relative bioavailability of the drug was obtained by applying a bayesian method. The results showed an important decrease of the ampicillin absorption, while the expected bioavailability when administered through MJC was 0.24, and the 95% interval (0.19, 0.30). The expected bioavailability of metronidazol when administered through MJC was 0.84, and the 95% interval (0.66, 1.07). This new route of drug administration in patients who undergo abdominal surgery, is shown to be of great importance from a clinical point of view, and should be kept in mind.
Adult↗