Assessment of the systemic effects of budesonide inhaled from Easyhaler and from Turbuhaler in healthy male volunteers

The main objective of this study was to show dose-dependent equivalence in the systemic activity of budesonide 800 microg day(-1) and 1600 microg day(-1) delivered from either Easyhaler or Turbuhaler in healthy male subjects. This single-centre study was carried out according to a randomized, double-blind, double-dummy, five-way crossover design over a 9-week period. All subjects received 1 week of treatment with the following, in randomized order, with a washout week between each treatment: budesonide Easyhaler 800 microg day(-1) plus placebo Turbuhaler; budesonide Easyhaler 1600 microg day(-1) plus placebo Turbuhaler; placebo Easyhaler plus Pulmicort Turbuhaler 800 microg day(-1); placebo Easyhaler plus Pulmicort Turbuhaler 1600 microg day(-1); placebo Easyhaler plus placebo Turbuhaler. The final inhalation of study drug was performed at the study centre, where blood and urine samples were collected. Fifteen subjects were recruited and all completed the study. Mean serum cortisol AUC0-20 values (the primary outcome variable) were comparable for each device at the two dose levels, and met the defined criteria for equivalence (90% CI 0.8-1.25 for between-treatment difference). Budesonide 800 microg day(-1) caused minimal suppression of serum cortisol AUC0-20 values, Budesonide 1600 microg day(-1) statistically significantly suppressed serum cortisol AUC0-20 values compared with placebo. Mean morning serum cortisol values were within the reference range in al treatment groups. At a budesonide dose of 800 microg day(-1) mean urine cortisol/creatinine ratio was statistically significantly higher with Easyhaler than with Turbuhaler, but there was no significant difference between the devices at the 1600 microg day(-1) dose. Serum budesonide concentrations were equivalent for each device at both dose levels. Adverse drug reactions were infrequent and mild in nature and there were no clinically significant changes in laboratory safety variables. In conclusion, in healthy male volunteers, budesonide 800 microg day(-1) and 1600 microg day inhaled from Easyhaler had comparable systemic effects to the same doses inhaled via Turbuhaler.

Assessment of the systemic effects of beclomethasone dipropionate inhaled via Easyhaler or via Diskhaler in healthy male volunteers

OBJECTIVE

The objective of this study was to compare the systemic effects of a moderate dose (800 microg/day) with the highest recommended dose (1600 microg/day) of beclomethasone dipropionate (BDP) inhaled via either Easyhaler or Diskhaler in 15 healthy adult male volunteers.

METHODS

This was an open, placebo-controlled, randomised study conducted according to a crossover design and consisting of a 1-week baseline period and five 1-week treatment periods, each separated by a 1-week washout period. Subjects received in randomised order 800 microg/day BDP via Easyhaler, 1600 microg/day BDP via Easyhaler, placebo via Easyhaler, 800 microg/day BDP via Diskhaler and 1600 microg/day BDP via Diskhaler. Subjects inhaled BDP twice daily at 0800 hours and 2000 hours. The last dose of each period was inhaled at the study site. Venous blood samples were drawn prior to and at 2-hour intervals for 20 h after the last dose. Serum cortisol area under the curve (AUC0-20) and morning serum cortisol values were determined using radioimmunoassay. Urine for analysis of urine cortisol/creatinine ratios (UCC) was collected over a 12-h period after the last dose of each treatment period.

RESULTS

According to serum cortisol values, no systemic effects were detected with BDP 800 microg/day inhaled via Easyhaler. The mean (+/-SD) change in serum cortisol AUC0-20 was +118.3+/-1391 nmol h/l compared with placebo. Mean (SD) changes from placebo in serum cortisol AUC0-20 values after BDP 1600 microg/day were--546.3+/-1004 nmol h/l with Easyhaler and -769.3+/-596 nmol h/l with Diskhaler. However, there were no statistically significant differences in systemic bioactivity between the active treatments. Morning serum cortisol levels and UCC ratios were consistent with the serum cortisol AUC0-20 data.

CONCLUSIONS

In conclusion, BDP 800 microg/day inhaled via Easyhaler did not reduce serum cortisol AUC0-20 compared with placebo. Although the decrease in hypothalamic pituitary-adrenal (HPA) axis function after BDP 1600 microg/day was statistically significant compared with placebo, the reduction was small and similar with both devices.

Effect of dose on the absorption of estradiol from a transdermal gel

OBJECTIVES

To study whether dose adjustments in transdermal estradiol gel treatment would result in proportional changes in estradiol bioavailability and concentrations.

METHODS

In an open study, 23 healthy postmenopausal women were treated consecutively with 0.5, 1.0 and 1.5 mg estradiol daily as a transdermal gel. Each dose was given for 16 days. Venous blood samples for serum estradiol and estrone measurements with RIA were taken at steady state on the 16th study day. From these concentrations, pharmacokinetic parameters for estradiol were calculated and corrected to correspond to equal dose by dividing the values by the dose.

RESULTS

Area under the estradiol time-concentration curve and peak estradiol level increased linearily and dose-proportionally with daily estradiol doses of 0.5-1.5 mg. This was shown by lack of significant differences in the dose-corrected parameters. However, the 90% confidence intervals between the doses were outside the commonly accepted levels for bioequivalence. Peak estradiol level was clearer and occurred earlier with the highest 1.5 mg estradiol dose, while more stable estradiol levels were seen with the lowest 0.5 mg estradiol dose.

CONCLUSIONS

The amount of estradiol on a certain skin area seems to be the determining factor in absorption. With higher estradiol doses, the absorption will be accelerated with a clearer peak estradiol level. The linear and dose proportional absorption indicates that flexible dose adjustments within the dose range of 0.5-1.5 mg estradiol daily can be made with an anticipated effect in estradiol bioavailability and concentrations.

Steady-state pharmacokinetics of oestradiol gel in post-menopausal women: effects of application area and washing

OBJECTIVE

To investigate the effect of cutaneous application area on oestradiol absorption using an oestradiol gel for transdermal use. Furthermore, the effect of washing of the application site on oestradiol pharmacokinetics was studied.

DESIGN

Open-label, randomised, three-way cross-over study.

SETTING

A clinical pharmacokinetic research unit.

SUBJECTS

Sixteen healthy postmenopausal volunteers.

INTERVENTIONS

During three treatment periods, subjects were treated with 1 mg oestradiol (1.0 g Divigel/Sandrena 0.1% gel), applied on the thigh to a skin area of 200 cm2, 400 cm2, or on an area 'as large as possible'. Blood samples were drawn during steady-state (on days 14-15) immediately before application and at regular time intervals thereafter.

MAIN OUTCOME MEASURES

Serum oestradiol levels were measured for determination of peak concentration (Cmax), time to peak concentration (tmax) and bioavailability using the area under the time concentration curve (AUC0-24).

RESULTS

Bioavailability from a 200 cm2 area was 2-fold higher than that from the largest possible area (P < 0.05). Oestradiol peak plasma concentration from a 200 cm2 area was higher than from the two larger areas (P < 0.05), which did not differ significantly from each other. Washing of the application site 30 min after application reduced the bioavailability from both the 200 cm2 and 400 cm2 application areas (P < 0.01), but peak plasma concentration from the 200 cm2 area only (P < 0.01). Time to reach peak plasma concentrations was significantly reduced with all three application areas by washing.

CONCLUSION

A higher oestradiol absorption was achieved from a smaller application area. No marked differences were observed in the pharmacokinetics between 200 cm2 and 400 cm2 application areas, which are those recommended for this oestradiol gel preparation.