Biomedical subjects

C F Gusdorf

Publications and source records attributed to C F Gusdorf.

5 recordsLinked to original sources

PubMed1991

The effect of inhalation flow on the performance of a dry powder inhalation system.

Dry powder inhalation systems are composed of a small amount of active ingredients and a larger amount of filler. The drug particles are believed to be bound by the filler crystals. The complexes are too large to be inhaled and need to be separated before they enter the lungs. This is done by the air patients inhale through the inhaler. Asthmatics can show low inhalation flows and the performance of a dry powder inhaler at low flows was investigated. It was shown, that small particles (less than 5 microns) separate swiftly at low flows and larger particles (greater than 5 microns) will need higher flows. The conclusion is that dry powder inhalation preparation do not show a simple separation pattern.

Administration, Inhalation↗

PubMed1991

Bioequivalence of two formulations of piroxicam.

Two separate studies were performed with 12 volunteers in order to demonstrate the bioequivalence of 2 piroxicam (CAS 36322-90-4) tablet and 2 piroxicam suppository formulations after single dose administration. A validated reversed-phase HPLC method with UV-detection is described. Bioequivalence assessment was done by using the posterior probability of a mean ratio between 0.8 and 1.2, and by using the Two One-Sided Tests Procedure (i.e. the 90% confidence interval). The probability approach and the confidence interval approach were compared.

Adult↗

PubMed1988

Bronchospasmolytic effects of salbutamol as powder inhalation in patients with reversible bronchial obstruction.

In a double-blind double-dummy crossover study, the effects of salbutamol dry powder inhaled from Salbutamol cyclocaps Pharbita 0.4 mg with the Pharbita inhaler and from a reference product were compared. On the first trial day, a single dose of one of the two preparations was administered, and 2 days later a single dose of the another preparation was administered, in random order. The effects on lung function (FEV1) were monitored from 15 to 360 min after administration. For both products the increase in FEV1 with reference to baseline values was statistically highly significant. There was no significant difference between the products.

Adult↗

PubMed1987

Single dose bioavailability of two different digoxin tablets.

In a single dose bioequivalence study in 10 healthy young adults the absorption profiles and bioavailability of two digoxin containing tablets (A = digoxin-Pharbita 0.25 mg and reference drug B) were compared and related to the in vitro dissolution rate of both tablets. Two tablets of each product (= 0.50 mg of digoxin) were taken at random on an empty stomach; two weeks elapsed between the two treatments. Frequent blood sampling was performed up to 24 h after intake of the dose. Digoxin plasma concentrations were measured by means of radioimmunoassay. No significant differences (p greater than 0.05) were found in the mean values of the peak plasma concentration (cmax), time to peak (tmax) and area under the plasma concentration versus time curve for the period of 0-10 h after drug intake (AUC0-10), although in most subjects the absorption process after intake of product A was slightly faster, with slightly higher peak. This might be related to a slightly faster release of digoxin from the product A dosage form, as was seen from the dissolution test data. The relative bioavailability of product A as compared to product B, accounted for 97.7 +/- 28.7% (mean +/- S.D.). These results indicate, that both products can be considered as being bioequivalent.

Adult↗

PubMed1986

Bioavailability of paracetamol after oral administration to healthy volunteers. Influence of caffeine on rate and extent of absorption.

The absorption rate and the bioavailability of two commercially available paracetamol tablets were investigated in a panel of seven volunteers; one of these tablets contained a combination of 50 mg caffeine and paracetamol. Considering the urinary excretion data, it is concluded that the tablets release their contents completely; the absolute bioavailability, however, calculated from plasma concentrations, is lower than 100%, indicating a first-pass effect. A marked interindividual variation in first-pass effect was noticed. No general influence of caffeine on the extent of absorption of paracetamol could be established; there is, however, a slightly positive influence of caffeine on the absorption rate of paracetamol in six out of seven volunteers. It was concluded that this positive influence on absorption rate is not responsible for the established enhancement of paracetamol analgesia by caffeine.

Acetaminophen↗