Characterization of the iontophoretic permselectivity properties of human and pig skin

Marro, Diego; Guy, Richard H.; Delgado‐Charro, M. Begoña

doi:10.1016/s0168-3659(00)00350-3

Cited by 168 publications

(109 citation statements)

References 7 publications

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“…However, degree of drug ionization at particular pH is of great importance, as unionized molecules predominantly diffuse through the lipophilic intercellular regions of the SC. On the other hand, the skin is negatively charged at physiological pH and therefore is cation-permselective (Marro et al, 2001). Furthermore, ionized drug molecules may also permeate through the intercellular regions of the SC, but in a slow and low mode.…”

Section: Drug Absorption In Skinmentioning

confidence: 99%

Basic considerations in the dermatokinetics of topical formulations

Nair

Jacob

Al‐Dhubiab

et al. 2013

Braz. J. Pharm. Sci.

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Assessing the bioavailability of drug molecules at the site of action provides better insight into the efficiency of a dosage form. However, determining drug concentration in the skin layers following topical application of dermatological formulations is a great challenge. The protocols followed in oral formulations could not be applied for topical dosage forms. The regulatory agencies are considering several possible approaches such as tape stripping, microdialysis etc. On the other hand, the skin bioavailability assessment of xenobiotics is equally important for topical formulations in order to evaluate the toxicity. It is always possible that drug molecules applied on the skin surface may transport thorough the skin and reaches systemic circulation. Thus the real time measurement of molecules in the skin layer has become obligatory. In the last two decades, quite a few investigations have been carried out to assess the skin bioavailability and toxicity of topical/dermatological products. This review provides current understanding on the basics of dermatokinetics, drug depot formation, skin metabolism and clearance of drug molecules from the skin layers following application of topical formulations.Uniterms: Dermatological formulations/pharmacokinetics. Dermatological formulations/ toxicity. Dermatokinetics. Skin/metabolism. Microdialysis. Tape stripping.A avaliação da biodisponibilidade de moléculas de fármacos no sítio de ação oferece melhor compreensão sobre a eficiência da forma de dosagem. Entretanto, a determinação da concentração de fármaco nas camadas da pele em seguida à aplicação tópica de formulações dermatológicas é um grande desafio. Os protocolos seguidos para as formulações orais não podem ser aplicados para as formulações tópicas. As agências regulatórias consideram várias abordagens possíveis, tape stripping, microdiálise etc. Por outro lado, a avaliação da biodisponibilidade de xenobióticos na pele é igualmente importante para as formulações tópicas para se avaliar a toxicidade. É sempre possível que as moléculas de fármaco aplicadas na superfície da pele sejam transportadas através da pele e alcancem a circulação sistêmica. Assim, a medida em tempo real de moléculas na camada da pele tem se tornado obrigatória. Nas últimas duas décadas, realizaram-se poucas pesquisas para avaliar a biodisponibilidade da pele e a toxicidade de produtos tópicos/dermatológicos. Esta revisão fornece a compreensão atual com base na dermatocinética, formação de fármaco de depósito, metabolismo da pele e o clearance das moléculas de fármaco das camadas da pele em seguida à aplicação de formulações tópicas.Unitermos: Formulações dermatológicas/farmacocinética. Formulações dermatológicas/toxicidade. Dermatocinética Pele/metabolismo. Microdiálise. Tape stripping.

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Section: Drug Absorption In Skinmentioning

confidence: 99%

Basic considerations in the dermatokinetics of topical formulations

Nair

Jacob

Al‐Dhubiab

et al. 2013

Braz. J. Pharm. Sci.

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“…According to the hypothesis of Imanidis and Luetolf, the stratum corneum can be compared as a composite model having distinct aqueous and lipoidal domains and has an isoelectric pH of 4.5 (33). Skin's permselectivity also depends strongly on the pH of the surrounding media as the overall charge density at these different areas is affected by environmental pH (pH of the donor and receiver system) (34,35). Direction and magnitude of electroosmotic solvent flow is influenced by the surface charge of the barrier membrane and as little as a pH difference of 0.4 units can affect this charge distribution and influence the permeation kinetics (33), Higher flux in pH 7.4 than in pH 4 was reported in case of lysine which was attributed to the neutralization of skin (19).…”

Section: Resultsmentioning

confidence: 99%

Screening of Venlafaxine Hydrochloride for Transdermal Delivery: Passive Diffusion and Iontophoresis

Singh

Ghosh²,

Dave³

et al. 2008

AAPS PharmSciTech

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Abstract. The objective of the study was to investigate in vitro transdermal delivery of venlafaxine hydrochloride across the pigskin by passive diffusion and iontophoresis. For passive diffusion, experiments were carried out in Franz diffusion cell whereas for iontophoretic permeation, the diffusion cell was modified to contain both the donor and return electrode on the same side of skin. Anodal iontophoresis was carried out using a current density of 0.5 mA/cm 2 . Donor concentrations used were 585.5 mg/ml (saturated solution) and 100 mg/ml. Experiments initially performed to determine the transport efficiency of venlafaxine ions showed promising results. Iontophoresis increased the permeation rate at both concentration levels over their passive counterparts (P<0.01), but surprisingly higher steadystate flux was obtained from lower donor drug load (P<0.01). The favorable pH of the unsaturated solutions is suggested to be the cause for this effect. Mild synergistic effect was observed when iontophoresis was carried out incorporating peppermint oil in the donor but the same was not found in passive diffusion. Highest steady-state flux obtained in the experiment was 3.279 μmol/cm 2 /h when peppermint oil (0.1%) was included in the donor. As the maintenance requirement of venlafaxine hydrochloride is approximately 9.956 μmol/h, the results suggested that the drug is a promising candidate for iontophoretic delivery.

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“…Thus, the direction of the solvent flow depends significantly on the isoelectric point (pI) of the skin membrane, which in turn depends on the pH of applied aqueous solution. 11) In addition, electrosmosis flow was significantly affected by additives in the formulation or applied physical means. 12,13) We have already examined the effect of EP pretreatment on electroosmosis and reported that the electroosmotic flow decreased with an increase in the applied strength of EP.…”

Section: )mentioning

confidence: 99%

Effect of Combination of Low-Frequency Sonophoresis or Electroporation with Iontophoresis on the Mannitol Flux or Electroosmosis through Excised Skin

Tokumoto

Higo

Todo

et al. 2016

Biological & Pharmaceutical Bulletin

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In vitro permeation studies of mannitol were conducted across excised hairless mouse skin to determine and compare the enhancing effect of electroporation (EP) or sonophoresis (SP) combined with iontophoresis (IP) on the electroosmotic flow, and to analyze the enhancement mechanism of these combined methods. Mannitol flux was utilized as an index for the electroosmotic flow due to its low molecular weight and no electrorepulsion effect. The combination of SP and IP (SP/IP) resulted in an apparent increase of electroosmotic flow (no effect was sometimes observed by SP/IP), while that of EP and IP (EP/IP) had no synergistic enhancing effect on the electroosmosis. Next, the combined effect of tape-stripping (TS) and IP (TS/IP) was examined in a similar manner to clarify the difference between the SP/IP and EP/IP effects on electroosmosis. When the TS number increased from 0 to 3, the electroosmotic flow increased with the TS number. However, no further increase was observed when the TS number became more than 3, and the flow started to decrease when the TS number became 5. The electric charge of the skin surface was then measured after SP or TS application. When SP was applied, the skin surface charge became much more negative and the electroosmotic flow by SP/IP was markedly increased. Thus, an increase in the electroosmotic flow across the skin during IP application can be obtained not by EP and TS, but by SP. The combined use of SP and IP is a promising means for the enhanced skin delivery of non-electrolyte drugs.Key words sonophoresis; electroporation; iontophoresis; electroosmosis; tape-stripping Recently, advances in development and practical application of physical transdermal drug delivery techniques have been achieved in iontophoresis (IP), sonophoresis (SP) and electroporation (EP). Although conventional transdermal delivery is based on passive diffusion using the concentration gradient of drugs through the skin barrier after topical application, these physical means are characterized by active drug administration based on physical perforation of the skin barrier using external energy sources, and can be used to deliver peptides, proteins and other macromolecular drugs as well as low-molecular-weight organic drugs.Among these techniques, IP 1) and EP 2) are based on electrical energy. IP, involving the application of a weak current for a relatively long period, is a means of using electrical repulsive force (electrorepulsion) and electroosmotic flow (electroosmosis) as driving forces.3) EP, involving the application of a high voltage (100 to 1000 V) for a very short period (100 µs to 100 ms), is used to form new aqueous pathways in the lamellar structure of the stratum corneum.2,4) The EP effect depends on the electric field applied to the skin. 5) SP6) is a skin-penetration-enhancing technique involving the application of a low frequency to the skin surface through media such as aqueous solution.Recently, several combined trials of EP/IP have been reported using insulin, 7) 5-fluorouracil 8) and calcito...

show abstract

Characterization of the iontophoretic permselectivity properties of human and pig skin

Cited by 168 publications

References 7 publications

Basic considerations in the dermatokinetics of topical formulations

Basic considerations in the dermatokinetics of topical formulations

Screening of Venlafaxine Hydrochloride for Transdermal Delivery: Passive Diffusion and Iontophoresis

Effect of Combination of Low-Frequency Sonophoresis or Electroporation with Iontophoresis on the Mannitol Flux or Electroosmosis through Excised Skin

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