Effect of Pulse on Iontophoretic Delivery of Desmopressin Acetate in Rats.

Nakakura, Masashi; Kato, Yasuki; Hayakawa, Eiji; Ito, Kunio; Kuroda, Tokuyuki

doi:10.1248/bpb.19.738

Cited by 10 publications

(8 citation statements)

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“…14) In other words, the resistance depended on the duty cycle. In contrast, Chen and Chien, 15) Chien et al 16) and Nakakura et al 14) showed that the duty cycle contributed to the percutaneous absorption of a drug. To clarify the effect of duty cycle on barrier function, the proposed method was used.…”

Section: Resultsmentioning

confidence: 99%

“…The rectangular waveform was selected to discuss the relationship between frequency and the absorption of the drug in previous studies. 7,14,15) Although the initial values were almost the same until 1000 Hz, the rate constant decreased more than 100 Hz as shown in Fig. 8.…”

Section: Effect Of Waveforms Chen and Chienmentioning

confidence: 89%

“…16) On the other hand, Bagniefski et al 7) and Nakakura et al 14) showed that the effect of frequency on the absorption of the drug was almost unrecognizable. To clarify the effect of frequency on the barrier function, our proposed method was examined.…”

Section: Effect Of Waveforms Chen and Chienmentioning

confidence: 99%

“…With respect to the absorption of drug, Bagniefski and Burnette 7) and Nakakura et al 14) reported that the frequency did not affect the absorption. It was assumed that the effect of frequency on the barrier function was low because they used more than 1 kHz.…”

Section: Effect Of Waveforms Chen and Chienmentioning

confidence: 99%

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Evaluation of Skin Barrier Function Using Direct Current II: Effects of Duty Cycle, Waveform, Frequency and Mode.

Kanebako¹,

Inagi²,

Takayama

2002

Biological & Pharmaceutical Bulletin

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The aim of this study was to evaluate the reduction in skin barrier function caused by pulsed iontophoresis by measuring resistance in the short term. Experiments under direct current (DC) and pulsed direct current (PDC) conditions were carried out using rat abdominal skin in vivo. The resistance was measured every 62.5 m ms and analyzed using a two-compartment model consisting of surface and skin resistance. Moreover, the initial value and the rate constant of surface resistance were calculated with the non-linear approximation program. Using this method, effects of duty cycle, waveform, frequency and mode on the skin barrier function were examined. The barrier function decreased with increasing duty cycle. With regard to waveforms, the influence on the skin barrier function was greatest in the order of sine, rectangular, saw and triangular waveforms. A frequency of less than 100 Hz reduced the barrier function. Considering the reduction in barrier function and skin polarization, the PDC of a rectangular waveform (around 75% as duty cycle and less than 100 Hz as frequency) or sine waveform was most suitable. In addition, the difference in the amount of drug delivered by DC and by PDC was discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Effect Of Waveforms Chen and Chienmentioning

confidence: 89%

Section: Effect Of Waveforms Chen and Chienmentioning

confidence: 99%

Section: Effect Of Waveforms Chen and Chienmentioning

confidence: 99%

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Evaluation of Skin Barrier Function Using Direct Current II: Effects of Duty Cycle, Waveform, Frequency and Mode.

Kanebako¹,

Inagi²,

Takayama

2002

Biological & Pharmaceutical Bulletin

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“…Adipose tissue is bad conductor of electrical current, causing an increase in impedance. Although some studies have reported that the frequency variation would not influence the decrease in skin impedance [ 18 , 42 , 56 ], Chien et al [ 40 ] reported that the skin impedance declined with increasing current frequencies. In our study, PDC with a frequency of 1,000 Hz showed lower impedance than CDC, providing adequate sweat production.…”

Section: Discussionmentioning

confidence: 99%

Pulsed direct and constant direct currents in the pilocarpine iontophoresis sweat chloride test

et al. 2014

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BackgroundThe classic sweat test (CST) is the golden standard for cystic fibrosis (CF) diagnosis. Then, our aim was compare the production and volume of sweat, and side effects caused by pulsed direct current (PDC) and constant direct current (CDC). To determine the optimal stimulation time (ST) for the sweat collection. To verify the PDC as CF diagnosis option.MethodsProspective study with cross-sectional experimental intervention. Experiment 1 (right arm): PDC and CDC. ST at 10 min and sweat collected at 30 min. Currents of 0.5; 0.75; 1.0 and 1.5 mA and frequencies of 0, 200, 1,000 and 5,000 Hz applied. Experiment 2 (left arm): current of 1.0 mA, ST at 5 and 10 min and sweat collected at 15 and 30 min with frequencies of 0; 200; 1,000 and 5,000 Hz applied Experiments 1 and 2 were performed with current density (CD) from 0.07 to 0.21 mA/cm2. Experiment 3: PDC was used in typical CF patients with two CFTR mutations screened and or with CF diagnosis by rectal biopsy and patients with atypical CF.Results48 subjects (79.16% female) with average of 29.54 ± 8.87 years old were enrolled. There was no statistical difference between the interaction of frequency and current in the sweat weight (p = 0.7488). Individually, positive association was achieved between weight sweat and stimulation frequency (p = 0.0088); and current (p = 0.0025). The sweat production was higher for 10 min of stimulation (p = 0.0023). The sweat collection was better for 30 min (p = 0.0019). The skin impedance was not influenced by ST and sweat collection (p > 0.05). The current frequency was inversely associated with the skin impedance (p < 0.0001). The skin temperature measured before stimulation was higher than after (p < 0.0001). In Experiment 3 (29 subjects) the PDC showed better kappa index compared to CDC (0.9218 versus 0.5205, respectively).ConclusionsThe performance of the CST with CDC and PDC with CD of 0.14 to 0.21 mA/cm2 showed efficacy in steps of stimulation and collection of sweat, without side effects. The optimal stimulation time and sweat collection were, respectively, 10 and 30 min.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2466-14-198) contains supplementary material, which is available to authorized users.

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