PubMed · 10692207
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
M Purucker, W Swann. 2000. Potential for duragesic patch abuse.. https://doi.org/10.1016/s0196-0644(00)70091-6
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
OBJECTIVE: To investigate the efficacy and tolerability of a new 7-day transdermal sequential estradiol/levonorgestrel patch (Fem7 Combi; Merck KGaA; Germany), versus placebo, as hormone replacement therapy in menopausal women. METHODS: A multicentre, randomized, clinical study consisting of a 3-week screening phase, a 12-week double-blind, placebo-controlled treatment phase, and a 12-week open, follow-up phase. Women aged 40-65 years with an intact uterus and menopausal complaints were randomized to either 2 weeks of an estradiol mono patch (50 microg per 24 h) followed by 2 weeks of an estradiol/levonorgestrel combination patch (50 microg/10 microg per 24 h), or a placebo patch, for three 28-day cycles. Changes in the Kupperman Index and the frequency of hot flushes were assessed. RESULTS: The sequential use of a 7-day estradiol patch and a 7-day estradiol/levonorgestrel patch was superior to placebo in reducing menopausal symptoms, and was well tolerated. At the end of the treatment phase, there was a statistically significant reduction in the Kupperman Index score versus placebo (P<0.0001), and a statistically significant difference between groups in the proportion of patients with a reduction in the number of hot flushes (at least 50% versus baseline). During the open follow-up phase, there was a marked reduction in the Kupperman Index score and the number of hot flushes for patients switched from placebo to active study medication. The active medication was effective throughout the 1-week application period. CONCLUSIONS: The new 7-day transdermal sequential estradiol/levonorgestrel patch was well tolerated, providing rapid and effective relief of menopausal symptoms. The addition of low-dose levonorgestrel did not influence the beneficial effects of estradiol.
The effect of iontophoresis combined with treatment of other physical enhancement methods such as electroporation, low frequency ultrasound, and erbium:YAG (yttrium-aluminum-garnet) laser on the transdermal delivery of sodium nonivamide acetate (SNA) was examined in this present study. Iontophoresis increased the transdermal flux of SNA in vitro as compared to the passive diffusion without any enhancement. Furthermore, iontophoresis was always the most potent enhancement method for SNA permeation among the physical enhancement methods tested. Pulsing of high voltages (electroporation) followed by iontophoresis did not result in increased transport over iontophoresis alone. However, electroporation shortened the onset of transdermal iontophoretic delivery of SNA. Pretreatment of low frequency ultrasound (sonophoresis) alone on skin did not increase the skin permeation of SNA. The combination of iontophoresis and sonophoresis increased transdermal SNA transport more than each method by itself. The enhancement of drug transport across shunt routes and reduction of the threshold voltage in the presence of an electric field may contribute to this synergistic effect. Use of an erbium:YAG laser was a good method for enhancing transdermal absorption of SNA because it allows precise control of stratum corneum (SC) removal, and this ablation of SC could be reversible to the original normal status. The combination of laser treatment and iontophoresis also synergized the skin permeation of SNA, possibly due to a gradual drop in the electric resistance of the skin. The results in this present study point out that the choice of certain conditions with suitable physical enhancement methods can induce a synergistic effect on transdermal delivery of SNA during iontophoresis.
Sonophoresis at a frequency of 20 kHz has been shown to enhance transdermal drug delivery, a phenomenon referred to as low-frequency sonophoresis. This study provides an investigation of the dependence of low-frequency sonophoresis on various ultrasound parameters, including the distance of the horn from the skin, intensity, and frequency. We performed in vitro experiments with full thickness pig skin to measure enhancements of skin conductivity and drug permeability. Ultrasound was applied to pretreat the skin using a sonicator operating at a frequency of either 20 or 40 kHz. We also measured pitting of aluminum foil to measure cavitation, which is the principal mechanism of low-frequency sonophoresis. The skin conductivity enhancement was found to be inversely proportional to the distance of the horn from the skin. As the intensity increased, skin conductivity enhancement also increased up to a certain threshold, and then dropped off. The intensities (I(max)) at which maximum enhancement occur are about 14 W/cm2 for 20 kHz and 17 W/cm2 for 40 kHz. These findings may be useful in optimizing low-frequency sonophoresis. Overall, the dependence of transport on ultrasound parameters is similar to that of aluminum foil pitting. These results support the role of cavitation in low-frequency sonophoresis.