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Kirkby M, Sabri AHB, Holmes A, Moss GPJ, Scurr D. PAMAM dendrimers as mediators of dermal and transdermal drug delivery: a review. J Pharm Pharmacol 2024; 76:1284-1300. [PMID: 39045860 DOI: 10.1093/jpp/rgae080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 06/03/2024] [Indexed: 07/25/2024]
Abstract
OBJECTIVES Poly(amidoamine) dendrimers have been widely investigated as potential nanomaterials that can enhance the skin permeation of topically applied drugs. This article reviews the studies that have used dendrimers as penetration enhancers and examines the mechanisms by which enhancement is claimed. KEY FINDINGS A wide range of studies have demonstrated that, in certain circumstances and for certain drugs, the incorporation of dendrimers into a topically applied formulation can significantly increase the amount of drug passing into and through the skin. In some cases, dendrimers offered little or no enhancement of skin permeation, suggesting that the drug-dendrimer interaction and the selection of a specific dendrimer were central to ensuring optimal enhancement of skin permeation. Significant interactions between dendrimers and other formulation components were also reported in some cases. SUMMARY Dendrimers offer substantial potential for enhancing drug delivery into and across the skin, putatively by mechanisms that include occlusion and changes to surface tension. However, most of these studies are conducted in vitro and limited progress has been made beyond such laboratory studies, some of which are conducted using membranes of limited relevance to humans, such as rodent skin. Thus, the outcomes and claims of such studies should be treated with caution.
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Affiliation(s)
- Melissa Kirkby
- The School of Pharmacy and Bioengineering, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom
| | - Akmal Hidayat Bin Sabri
- The School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Amy Holmes
- The School of Pharmacy and Bioengineering, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom
| | - Gary P J Moss
- The School of Pharmacy and Bioengineering, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom
| | - David Scurr
- The School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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Kriplani P, Guarve K. Transdermal Drug delivery: A step towards treatment of cancer. Recent Pat Anticancer Drug Discov 2021; 17:253-267. [PMID: 34856914 DOI: 10.2174/1574892816666211202154000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/15/2021] [Accepted: 11/15/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Transdermal drug delivery is an emerging and tempting system over oral and hypodermic drug delivery system. With the new developments in skin penetration techniques, anticancer drugs ranging from hydrophilic macromolecules to lipophilic drugs can be administered via transdermal route to treat cancer. OBJECTIVE In the present review, various approaches to enhance the transdermal delivery of drugs is discussed including the micro and nanotechnology based transdermal formulations like chemotherapy, gene therapy, immunotherapy, phototherapy, vaccines and medical devices. Limitations and advantages of various transdermal technologies is also elaborated. METHOD In this review, patent applications and recent literature of transdermal drug delivery systems employed to cure mainly cancer are covered. RESULTS Transdermal drug delivery systems have proved their potential to cure cancer. They increase the bioavailability of drug by site specific drug delivery and can reduce the side effects/toxicity associated with anticancer drugs. CONCLUSION The potential of transdermal drug delivery systems to carry the drug may unclutter novel ways for therapeutic intercessions in various tumors.
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Affiliation(s)
- Priyanka Kriplani
- Guru Gobind Singh College of Pharmacy, Yamuna Nagar 135001, Haryana. India
| | - Kumar Guarve
- Guru Gobind Singh College of Pharmacy, Yamuna Nagar 135001, Haryana. India
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3
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Tissue Levels of Flurbiprofen in the Rat Plantar Heel after Short-Duration Topical Iontophoresis Are Sufficient to Induce Pharmacodynamic Responses to Local Pain Stimuli. Pharmaceutics 2020; 12:pharmaceutics12070608. [PMID: 32629832 PMCID: PMC7408369 DOI: 10.3390/pharmaceutics12070608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/27/2020] [Accepted: 06/28/2020] [Indexed: 11/16/2022] Open
Abstract
The objective of this study was to investigate the topical iontophoresis of flurbiprofen (FBF) as a means to enhance its local bioavailability and thereby provide an improved and targeted treatment of plantar heel pain. Initial in vitro experiments using porcine ear skin investigated iontophoretic transport of FBF under different conditions. Local FBF biodistribution in the rat paw in vivo was compared after topical or oral administration. Efficacy of pain management was investigated using a plantar incisional model by evaluating pharmacodynamic responses to local pain stimuli. The results demonstrated that iontophoresis of FBF significantly increased cutaneous deposition and transdermal permeation of FBF as compared to passive delivery—it also enabled drug input to be controlled by modulation of current density and drug concentration (r2 > 0.99). Topical iontophoresis of FBF in vivo enabled higher drug levels in skin and muscle in rat plantar aspect and superior pharmacodynamic responses to local pain stimuli, in comparison to oral and passive delivery. In conclusion, short-duration topical iontophoresis of FBF may better help to relieve plantar heel pain than oral or passive administration, which should be of clinical interest.
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Dumont C, Prieto P, Asturiol D, Worth A. Review of the Availability ofIn VitroandIn SilicoMethods for Assessing Dermal Bioavailability. ACTA ACUST UNITED AC 2015. [DOI: 10.1089/aivt.2015.0003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Coralie Dumont
- The European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM), Institute for Health and Consumer Protection, European Commission Joint Research Centre, Ispra, Italy
| | - Pilar Prieto
- The European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM), Institute for Health and Consumer Protection, European Commission Joint Research Centre, Ispra, Italy
| | - David Asturiol
- The European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM), Institute for Health and Consumer Protection, European Commission Joint Research Centre, Ispra, Italy
| | - Andrew Worth
- The European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM), Institute for Health and Consumer Protection, European Commission Joint Research Centre, Ispra, Italy
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Tunku Mahmud TH, Abdul-Aziz A, Muda R. A Review on the Potential Use of Chitosan-Based Delivery System in Mild Facial Cleansing Formulation. INT J POLYM MATER PO 2015. [DOI: 10.1080/00914037.2014.958832] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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6
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Modeling the human skin barrier--towards a better understanding of dermal absorption. Adv Drug Deliv Rev 2013; 65:152-68. [PMID: 22525516 DOI: 10.1016/j.addr.2012.04.003] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 04/03/2012] [Accepted: 04/09/2012] [Indexed: 12/29/2022]
Abstract
Many drugs are presently delivered through the skin from products developed for topical and transdermal applications. Underpinning these technologies are the interactions between the drug, product and skin that define drug penetration, distribution, and elimination in and through the skin. Most work has been focused on modeling transport of drugs through the stratum corneum, the outermost skin layer widely recognized as presenting the rate-determining step for the penetration of most compounds. However, a growing body of literature is dedicated to considering the influence of the rest of the skin on drug penetration and distribution. In this article we review how our understanding of skin physiology and the experimentally observed mechanisms of transdermal drug transport inform the current models of drug penetration and distribution in the skin. Our focus is on models that have been developed to describe particular phenomena observed at particular sites of the skin, reflecting the most recent directions of investigation.
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7
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Edwards F, Tsakmaka C, Mohr S, Fielden PR, Goddard NJ, Booth J, Tam KY. Using droplet-based microfluidic technology to study the precipitation of a poorly water-soluble weakly basic drug upon a pH-shift. Analyst 2013; 138:339-45. [DOI: 10.1039/c2an36364j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Porter WR. Warfarin: history, tautomerism and activity. J Comput Aided Mol Des 2010; 24:553-73. [PMID: 20352297 DOI: 10.1007/s10822-010-9335-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 03/13/2010] [Indexed: 10/19/2022]
Abstract
The anticoagulant drug warfarin, normally administered as the racemate, can exist in solution in potentially as many as 40 topologically distinct tautomeric forms. Only 11 of these forms for each enantiomer can be distinguished by selected computational software commonly used to estimate octanol-water partition coefficients and/or ionization constants. The history of studies on warfarin tautomerism is reviewed, along with the implications of tautomerism to its biological properties (activity, protein binding and metabolism) and chemical properties (log P, log D, pK (a)). Experimental approaches to assessing warfarin tautomerism and computational results for different tautomeric forms are presented.
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Affiliation(s)
- William R Porter
- Global Pharmaceutics and Life Cycle Technology, Dept. R43D, Bldg. AP31, Abbott Laboratories, 200 Abbott Park Road, Abbott Park, IL 60064, USA.
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9
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Duracher L, Blasco L, Abdel Jaoued A, Vian L, Marti-Mestres G. Irradiation of Skin and Contrasting Effects on Absorption of Hydrophilic and Lipophilic Compounds. Photochem Photobiol 2009; 85:1459-67. [DOI: 10.1111/j.1751-1097.2009.00599.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Abdulmajed K, McGuigan C, Heard CM. Topical Delivery of Retinyl Ascorbate Co-Drug. Skin Pharmacol Physiol 2006; 19:248-58. [PMID: 16778457 DOI: 10.1159/000093980] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 10/14/2005] [Indexed: 11/19/2022]
Abstract
Chemical and enzymatic hydrolysis of the co-drug of retinoic acid (vitamin A) and ascorbic acid (vitamin C) - retinyl ascorbate (RA-AsA)--have been studied. Firstly, the amount of protein and ester hydrolysis activity was determined in crude cellular extracts from freshly excised porcine ear skin (<3 h) and stored porcine ear skin (frozen >6 months) using ethyl butyrate as model substrate. The stability of RA-AsA was then determined in the crude cell extracts with and without additional antioxidants. Lastly, the enzymatic hydrolysis of RA-AsA and retinyl-2-carboxy-2-hydroxy-ethanoate were determined by incubating with porcine liver esterase - retinol palmitate and ascorbyl palmitate were included for comparison. Freshly excised skin contained higher amounts of active proteins than previously frozen skin. RA-AsA underwent hydrolytic reduction causing the AsA moiety to disintegrate due to the presence of free radicals in the media. An intermediate was produced that seemed to be cleaved by enzymes. Addition of ascorbic acid, as antioxidant, to the media of crude protein extracts decelerated the hydrolysis rate. This was supported when RA-AsA and retinyl-2-carboxy-2-hydroxy-ethanoate were incubated separately with pure esterase. There was approximately 5-fold more soluble protein per ml of cytosol in the fresh skin compared to the stored skin. Therefore, the amount of protein present within approximately 1.5 cm(2) of skin (average diffusion area in the Franz cells used in our skin penetration studies) was 0.06 mg cm(-2) and 0.01 mg cm(-2) for fresh and stored extracts, respectively.
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Affiliation(s)
- K Abdulmajed
- Welsh School of Pharmacy, Cardiff University, Cardiff, UK
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11
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Pellanda C, Ottiker E, Strub C, Figueiredo V, Rufli T, Imanidis G, Surber C. Topical bioavailability of triamcinolone acetonide: effect of dose and application frequency. Arch Dermatol Res 2006; 298:221-30. [PMID: 16858572 DOI: 10.1007/s00403-006-0677-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 06/14/2006] [Accepted: 06/20/2006] [Indexed: 11/26/2022]
Abstract
The application frequency of topical corticosteroids is a recurrently debated topic. Multiple-daily applications are common, although a superior efficacy compared to once-daily application is not unequivocally proven. Only few pharmacokinetic studies investigating application frequency exist. The aim of the study was to investigate the effect of dose (Experiment 1) and application frequency (Experiment 2) on the penetration of triamcinolone acetonide (TACA) into human stratum corneum (SC) in vivo. The experiments were conducted on the forearms of 15 healthy volunteers. In Experiment 1, single TACA doses (300 microg/cm(2) and 100 microg/cm(2)) dissolved in acetone were applied on three sites per arm. In experiment 2, single (1 x 300 microg/cm(2)) and multiple (3 x 100 microg/cm(2)) TACA doses were similarly applied. SC samples were harvested by tape stripping after 0.5, 4 and 24 h (Experiment 1) and after 4, 8 and 24 h (Experiment 2). Corneocytes and TACA were quantified by UV/VIS spectroscopy and HPLC, respectively. TACA amounts penetrated into SC were statistically evaluated by a paired-sample t-test. In Experiment 1, TACA amounts within SC after application of 1 x 300 microg/cm(2) compared to 1 x 100 microg/cm(2) were only significantly different directly after application and similar at 4 and 24 h. In Experiment 2, multiple applications of 3 x 100 microg/cm(2) yielded higher TACA amounts compared to a single application of 1 x 300 microg/cm(2) at 4 and 8 h. At 24 h, no difference was observed. In conclusion, using this simple vehicle, considerable TACA amounts were retained within SC independently of dose and application frequency. A low TACA dose applied once should be preferred to a high dose, which may promote higher systemic exposure.
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Affiliation(s)
- Carolina Pellanda
- Hospital Pharmacy, University Hospital Basel, Spitalstrasse 26, 4031, Basel, Switzerland
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12
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Abdulmajed K, Heard CM, McGuigan C, Pugh WJ. Topical Delivery of Retinyl Ascorbate Co-Drug. Skin Pharmacol Physiol 2004; 17:274-82. [PMID: 15528957 DOI: 10.1159/000081112] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Accepted: 07/29/2004] [Indexed: 11/19/2022]
Abstract
Retinyl ascorbate (RA-AsA), an ester co-drug of vitamins A (RA) and C (AsA), is proposed as a topical antioxidant/cell division regulator for reducing UV-induced generation of free radicals and disrupted dermal cell growth. The efficacy of dermatological agents is influenced by their retention within the skin, which is increased by the interaction with skin components. Keratin is the major protein (approximately 95%) in the skin, and this paper reports the binding of RA-AsA, RA, AsA, retinol, ascorbic acid palmitate and retinol palmitate to three tissues-human callus, pig ear skin and bovine horn keratin. Tissue samples were incubated with solutions of compounds and the uptake measured as the ratio of bound/free compound at equilibrium. Binding to keratin was assessed using delipidised tissue, and was much higher for the polar compounds, suggesting dipolar/H-bonding interaction. Binding strength was ranked as human > porcine > bovine, but there was no distinction for highly lipophilic compounds. The binding characteristic of native tissues was complicated by lipid content of the tissues. There seemed to be a dual effect. The binding of very lipophilic materials increased with lipid content, implying that a substantial amount is dissolved in the lipid matrix. For highly polar AsA, lipid content decreased the binding, suggesting that the lipid reduced the strong polar interactions with skin protein/keratin.
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Affiliation(s)
- K Abdulmajed
- Welsh School of Pharmacy, Cardiff University, Cardiff, UK
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13
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Roberts MS, Cross SE, Anissimov YG. Factors affecting the formation of a skin reservoir for topically applied solutes. Skin Pharmacol Physiol 2004; 17:3-16. [PMID: 14755122 DOI: 10.1159/000074057] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2003] [Accepted: 08/22/2003] [Indexed: 11/19/2022]
Abstract
The reservoir function of the skin is an important determinant of the duration of action of a topical solute. The reservoir can exist in the stratum corneum, in the viable avascular tissue (viable epidermis and supracapillary dermis) and in the dermis. A steroid reservoir in the stratum corneum has been demonstrated by the reactivation of a vasoconstrictor effect by occlusion or application of a placebo cream to the skin some time after the original topical application of steroid. Other solutes have also been reported to show a reservoir effect in the skin after topical application. A simple compartmental model is used to understand why reactivation of vasoconstriction some time after a topical steroid application shows dependency on time, topical solute concentration and the product used to cause reactivation. The model is also used to show which solutes are likely to show a reservoir effect and could be potentially affected by desquamation, especially when the turnover of the skin is abnormally rapid. A similar form of the model can be used to understand the promotion of reservoir function in the viable tissue and in the dermis in terms of effective removal by blood perfusing the tissues.
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Affiliation(s)
- M S Roberts
- Department of Medicine, University of Queensland, Princess Alexandra Hospital, Ipswich Road, Buranda, Queensland 4102, Australia.
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Abdulmajed K, Heard CM. Topical delivery of retinyl ascorbate co-drug. Int J Pharm 2004; 280:113-24. [PMID: 15265552 DOI: 10.1016/j.ijpharm.2004.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Revised: 04/15/2004] [Accepted: 05/10/2004] [Indexed: 10/26/2022]
Abstract
A novel synthetic technique was used to synthesise the co-drug retinyl ascorbate (RA-AsA) ester from all-trans-retinyl chloride (RA) and L-ascorbic acid (AsA) suspended in ethanol at low temperature. Its log P, solubility in a Me:PBS, 50/50 at pH 4.8 and degradation constant were determined. The flux and permeation coefficient were determined using heat separated human skin membrane, and skin penetration was determined by tape stripping using full thickness human. All experiments were performed in parallel with retinyl palmitate (Rol-Pal) and ascorbyl palmitate (AsA-Pal), which are used in commercial topical formulations. RA-AsA exhibited favourable log P (2.2), with stability much greater than RA and AsA, but similar stability to Rol-Pal and AsA-Pal. The flux of RA-AsA was lower than for Rol-Pal and AsA-Pal. RA-AsA also demonstrated higher skin retention than the other two esters, but delivered more RA and AsA to the viable epidermis than retinol from Rol-Pal and ascorbic acid from AsA-Pal. Overall, the data suggest the potential value of RA-AsA co-drug for the purpose of treating damage to skin resulting from UV-induced production of free radicals.
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Affiliation(s)
- Kasem Abdulmajed
- Welsh School of Pharmacy, Cardiff University, Cardiff CF10 3XF, UK
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15
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Akomeah F, Nazir T, Martin GP, Brown MB. Effect of heat on the percutaneous absorption and skin retention of three model penetrants. Eur J Pharm Sci 2004; 21:337-45. [PMID: 14757507 DOI: 10.1016/j.ejps.2003.10.025] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effect of heat on the transdermal delivery of model penetrants of differing lipophilicity through artificial membranes (non-rate limiting) and human epidermis was investigated in vitro. Saturated suspensions of the model penetrants; methyl paraben (MP), butyl paraben (BP) and caffeine (CF) in deionised water (vehicle) were used to attain maximal thermodynamic activity. Franz cell experiments were performed at temperatures ranging from 23 to 45 degrees C using the infinite dose method. Artificial membrane studies showed the penetrant diffusivity (diffusion coefficient) in the vehicle to be totally dependent on temperature and not changes in donor solubility. Epidermal flux and retention of all penetrants was found to be affected by temperature. The amount of penetrant retained in the epidermis was found to be in the order BP>CF>MP whilst the transdermal fluxes increased in the order MP>BP>CF with increasing receptor temperature. Estimated epidermal diffusivity of MP was found to be significantly affected by temperature (P< or =0.05) compared to BP and CF. Using Arrhenius plots, a lower activation energy was recorded for CF and may suggest a difference in permeation kinetics compared to the other penetrants.
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Affiliation(s)
- Franklin Akomeah
- Department of Pharmacy, Franklin-Wilkins Building, Kings College London, 150 Stamford Street, SE1 9NN, London, UK.
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Raiman J, Hänninen K, Kontturi K, Murtomäki L, Hirvonen J. Drug Adsorption in Human Skin: A Streaming Potential Study. J Pharm Sci 2003; 92:2366-72. [PMID: 14603482 DOI: 10.1002/jps.10516] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The objective of this study was to investigate the drug adsorption process in human skin using in vitro streaming potential measurements. Streaming potential is an electrokinetic phenomenon, which reflects both the charge density and the pore size of a membrane. Thus, the adsorption of charged solutes on the pore walls can be detected as a change of streaming potential, viz., as a change in the slope deltaE/deltaP. In these streaming potential measurements, hydrophilic nadolol and luteinizing hormone-releasing hormone, and lipophilic propranolol and Nafarelin were used as model drugs. As could be expected, the hydrophilic drugs did not change the slope. The more lipophilic propranolol and Nafarelin, instead, changed the slope. Propranolol changed the slope gradually from negative to positive when the concentration was increased from 1 to 10 mM. With Nafarelin, a straight line with a slope of about 0 was obtained at pH 7.3 and an ascending curve at pH 4.2. These results indicate that the negative charges on the pore walls of human skin are blocked by adsorption of the lipophilic cations. The adsorption of lipophilic cations in the skin alters the permselectivity of the skin, which, in turn, may lead to the inhibition of electroosmotic flow across the skin during iontophoresis and to the shut down of transdermal drug permeation of higher molecular weight drugs.
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Affiliation(s)
- Johanna Raiman
- Pharmaceutical Technology Division and Viikki Drug Discovery Technology Center, Department of Pharmacy, PO Box 56, FIN-00014 University of Helsinki, Finland.
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Abstract
The localisation of primaquine was studied within epidermal membranes following the application of a topical dose. A depth profile was constructed by tape-stripping human epidermis following permeation of a 70 mgml(-1) solution of primaquine in Miglyol 840. Comparative binding studies of primaquine were carried out on isolated human stratum corneum and whole epidermis, using normal and delipidised tissue. An additional study was undertaken using bovine keratin powder as a model of human keratin. The depth profile showed that primaquine decreased with depth and decreasing keratin content, and the total primaquine recovered (15.5 mgcm(-2)) was 300 x the amount of extractable lipid. Binding to delipidised skin was saturable, whereas binding to normal skin was unsaturable, reflecting the high miscibility of drug in the lipid domains as opposed to a finite, but large number of binding sites on the corneocytes. Binding was greater for stratum corneum than stratum corneum plus viable epidermis, probably due to greater accessibility of corneocytes keratin. Binding was dose dependent, although binding to delipidised skin was far greater than to normal skin, demonstrating that primaquine had an affinity for lipoidal regions and an even higher affinity for the proteinaceous domains of the stratum corneum. This was supported by high saturable levels of primaquine binding to bovine horn keratin. The results indicated extensive binding to corneocyte keratin has a significant effect on reservoir formation and the permeability of primaquine across human skin. It is speculated that the large amount of keratin presented at the skin surface may be an evolutionary protective process for the sequestration of ingressing molecules.
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Affiliation(s)
- C M Heard
- Welsh School of Pharmacy, Cardiff University, Cardiff CF10 3XF, UK.
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Xiao H, Kaltashov IA, Eyles SJ. Indirect assessment of small hydrophobic ligand binding to a model protein using a combination of ESI MS and HDX/ESI MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2003; 14:506-515. [PMID: 12745220 DOI: 10.1016/s1044-0305(03)00135-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Direct mass spectrometric characterization of interactions between proteins and small hydrophobic ligands often poses a serious problem due to the complex instability in the gas phase. We have developed a method that probes the efficacy of ligand-protein interactions indirectly by monitoring changes in protein flexibility. The latter is assessed quantitatively using a combination of charge state distribution analysis and amide hydrogen exchange under both native and mildly denaturing conditions. The method was used to evaluate binding of a model protein cellular retinoic acid binding protein I to its natural ligand all-trans retinoic acid (RA), isomers 13-cis- and 9-cis-RA, and retinol, yielding the following order of ligand affinities: All-trans RA > 9-cis RA > 13-cis RA, with no detectable binding of retinol. This order is in agreement with the results of earlier fluorimetric titration studies. Furthermore, binding energy of the protein to each of retinoic acid isomers was determined based on the measured hydrogen exchange kinetics data acquired under native conditions.
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Affiliation(s)
- Hui Xiao
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA
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Yamamoto A, Setoh K, Murakami M, Shironoshita M, Kobayashi T, Fujimoto K, Okada N, Fujita T, Muranishi S. Enhanced transdermal delivery of phenylalanyl-glycine by chemical modification with various fatty acids. Int J Pharm 2003; 250:119-28. [PMID: 12480278 DOI: 10.1016/s0378-5173(02)00536-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We synthesized three novel lipophilic derivatives of phenylalanyl-glycine (Phe-Gly), C4-Phe-Gly, C6-Phe-Gly and C8-Phe-Gly by chemical modification with butyric acid (C4), caproic acid (C6) and octanoic acid (C8). The effect of the acylation on the stability, permeability and accumulation of Phe-Gly in the skin was investigated by in vitro studies. The stability of Phe-Gly in skin homogenates was low, but was significantly improved by the acylation. In the transport studies, a Franz-type diffusion cell was used for the permeability experiments with Phe-Gly and its acyl derivatives. The permeability of acyl-Phe-Gly derivatives across the intact skin was higher than that of native Phe-Gly. Of all the acyl-Phe-Gly derivatives, C6-Phe-Gly was the most permeable compounds across the intact skin. On the other hand, the permeability of acyl-Phe-Gly derivatives across stripped skin was less than that of native Phe-Gly in the initial time period of transport studies, but their permeability was higher than that of native Phe-Gly at the end of the transport studies. When the skin was pretreated with ethanol, which could inactivate the peptidases responsible for the degradation of Phe-Gly, the permeability of native Phe-Gly was higher than that of acyl derivatives. These findings indicated the involvement of peptidases on the permeability of Phe-Gly across the skin. The relationship between the lipophilic indexes of Phe-Gly derivatives and the permeability coefficients indicated that there is an optimal carbon number of fatty acid for improving the transdermal permeability of Phe-Gly by the acylation. A good correlation was found between the accumulation of these acyl-Phe-Gly derivatives in the intact skin and their lipophilicity. These results suggest that the stability and permeability of Phe-Gly were improved by chemical modification with fatty acids and this enhanced permeability of Phe-Gly by the acylation may be attributed to the protection of Phe-Gly from the enzymatic degradation in the skin and the increase in the partition of Phe-Gly to the stratum corneum.
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Affiliation(s)
- Akira Yamamoto
- Department of Biopharmaceutics, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan.
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Ogiso T, Hata T, Iwaki M, Tanino T. Transdermal absorption of bupranolol in rabbit skin in vitro and in vivo. Biol Pharm Bull 2001; 24:588-91. [PMID: 11379788 DOI: 10.1248/bpb.24.588] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study was designed to clarify the percutaneous penetration of bupranolol (BP), a beta-adrenoceptor antagonist, through rabbit skin and to compare the in vitro penetration with the in vivo absorption. BP penetrated across the skin slowly in the absence of enhancers in vitro. Isopropyl myristate and N-methyl-2-pyrrolidone enhanced the in vitro penetration, with a 3.6 times higher flux compared with that without enhancers. However, in the in vivo percutaneous absorption, the maximal penetration was obtained with the formulation added dlimonene, with a 3.0 times higher area under the concentration-time curve (AUC) than that for the formulation without enhancers. The plasma levels of BP determined, however, were extremely lower than the theoretical plasma steady-state concentrations predicted. The plasma levels of BP after application of these formulations were maintained in the range of 7-22 ng/ml for 30 h, of which concentrations were above the therapeutically effective concentration (1.5-4 ng/ml). Therefore, the transdermal systems will offer an efficient drug delivery system for the treatment of angina pectoris and tachycardia.
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Affiliation(s)
- T Ogiso
- Faculty of Pharmaceutical Sciences, Kinki University, Osaka, Japan.
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Affiliation(s)
- R Falabella
- Department of Dermatology, Universidad del Valle, Call, Colombia
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Hagedorn-Leweke U, Lippold BC. Accumulation of sunscreens and other compounds in keratinous substrates. Eur J Pharm Biopharm 1998; 46:215-21. [PMID: 9795067 DOI: 10.1016/s0939-6411(97)00165-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Several cosmetic ingredients, especially sunscreens, should be substantive, which means they are to be adsorbed to specific binding sites within the upper skin layers, particularly keratinized structures of the stratum corneum, and thus show resistance to washing off. We investigated the affinity of 10 non-ionic compounds, among these UV-absorbing chemicals, antioxidants, antimicrobial compounds and a repellent to animal keratin and human callus. In each case a linear relationship between the drug amount, which has accumulated in the respective keratin, and the remaining free concentration of the applied solution could be established. Moreover, drug affinities to keratinous substrates are in direct proportion to the octanol/vehicle partition coefficients, pointing to the fact, that drug enrichment in keratinic substrates is clearly governed by lipophilicity, while specific adsorption, i.e. genuine substantivity, does not seem to occur. After application of a saturated solution non-ionic compounds with a pronounced keratin/vehicle partition coefficient will build up the highest concentration within the stratum corneum. If these compounds show, at the same time, a high solubility in the vehicle, they will penetrate the skin most easily. The used callous tissue seems to be a suitable substrate to simulate and quantify solute uptake into human skin.
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23
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Hashiguchi T, Kodama A, Ryu A, Otagiri M. Retention capacity of topical imidazole antifungal agents in the skin. Int J Pharm 1998. [DOI: 10.1016/s0378-5173(97)00352-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Ionization conditions for iontophoretic drug delivery. Electrical conductance and aggregation of lidocaine hydrochloride in 1-octanol at 25°C. Int J Pharm 1997. [DOI: 10.1016/s0378-5173(97)00126-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Thysman S, Tasset C, Préat V. Transdermal iontophoresis of fentanyl: delivery and mechanistic analysis. Int J Pharm 1994. [DOI: 10.1016/0378-5173(94)90081-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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Weber LW. The penetration of 2,3,7,8-tetrachlorodibenzo-p-dioxin into viable and non-viable porcine skin in vitro. Toxicology 1993; 84:125-40. [PMID: 8266333 DOI: 10.1016/0300-483x(93)90112-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Freshly harvested, full thickness porcine skin was kept metabolically viable at 4 degrees C in a minimal essential medium for at least 48 h, as judged by the formation of lactate or 14CO2 from 14C-labeled glucose. In vitro topical exposure to the environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 65 ng/cm2) for up to 1000 min did not affect the viability of skin. The penetration and distribution of TCDD into porcine skin was studied in an in vitro system under a variety of conditions, such as viability status, different vehicles or concentrations, or artificial removal of the stratum corneum. Loss of viability of the skin increased the rate of penetration of TCDD by about 60%. Removal of the stratum corneum to mimic lesioned skin increased the rate of dermal penetration of TCDD about 3-fold. The use of acetone as the vehicle, simulating dermal exposure to TCDD as a dust or from a volatile solvent, resulted in higher rates of penetration than the use of mineral oil as the vehicle, which simulates the situation of industrial accidents. The percentage of dose absorbed was independent of the dose of TCDD (65 or 6.5 ng/cm2) administered to the surface of skin. Rates of dermal penetration of TCDD ranged form 14 to 985 pg/cm2 skin per h, or 0.2-1.5% of the dose/h, depending on the conditions of exposure. These rates of penetration are comparable with results obtained by others in several other species, with both in vitro and in vivo systems including human skin in vitro. Full thickness porcine skin, viable or previously frozen, is therefore a valid in vitro model to estimate dermal penetration of TCDD in humans.
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Affiliation(s)
- L W Weber
- Section of Environmental Toxicology, GSF-Institut für Toxikologie, Neuherberg, Germany
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27
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Pacifici GM, Viani A. Methods of determining plasma and tissue binding of drugs. Pharmacokinetic consequences. Clin Pharmacokinet 1992; 23:449-68. [PMID: 1458763 DOI: 10.2165/00003088-199223060-00005] [Citation(s) in RCA: 174] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The available techniques for the investigation of drug binding to plasma and tissues protein are reviewed and the advantages and disadvantages of the various techniques stated. A comparison of different plasma protein binding techniques is made which shows that the size of the unbound fraction of drug may be influenced by the method used. Protein binding may be assayed by methods including equilibrium dialysis, ultrafiltration, ultracentrifugation, gel filtration, binding to albumin microspheres and circular dichroism. Tissue binding techniques can involve testing binding to isolated organs, tissue slices, homogenates and isolated subcellular particles. Details of the available methods to compute pharmacokinetic constants are given. Stereoselective binding has been investigated for a limited number of drugs and the difference in the binding of 2 enantiomers is usually modest. The measurement of the binding constants is often required to characterise the drug-protein interaction. Mathematical and graphical methods to compute the pharmacokinetic parameters are discussed. The implications of binding on the volume of distribution and clearance of drugs are examined.
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Affiliation(s)
- G M Pacifici
- Department of Biomedicine, University of Pisa Medical School, Italy
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28
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Tissue Binding versus Plasma Binding of Drugs: General Principles and Pharmacokinetic Consequences. ADVANCES IN DRUG RESEARCH 1991. [DOI: 10.1016/b978-0-12-013320-8.50006-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Surber C, Wilhelm KP, Hori M, Maibach HI, Guy RH. Optimization of topical therapy: partitioning of drugs into stratum corneum. Pharm Res 1990; 7:1320-4. [PMID: 2095573 DOI: 10.1023/a:1015958526423] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To optimize a topical formulation for therapeutic effect generally implies that the flux of drug into the skin be maximized. This requirement means that the product of drug concentration in the vehicle (Cv) and drug partition coefficient (PC) between stratum corneum (SC) and vehicle be as large as possible. While Cv is a formulation variable which can be easily manipulated up to the drug's saturation solubility, PC is a parameter that is difficult to predict a priori. However, there is no question that an ability to evaluate PC would greatly facilitate the efficient screening of drugs and formulations. We have measured the SC/water and SC/isopropylmyristate (a model lipophilic vehicle) PCs of seven drugs; acitretin, progesterone, testosterone, diazepam, estradiol, hydrocortisone, and caffeine, SC/water PCs were determined as a function of the following variables: (i) initial drug concentration in the vehicle, (ii) length of equilibrium, (iii) SC source and preparation technique, and (iv) SC delipidization. The data obtained were reproducible and physicochemically consistent, and they show that useful partitioning information from both aqueous and nonaqueous vehicles can be obtained with the biological tissue of greatest relevance. The SC/water PCs of the steroids were in reasonable agreement with previous measurements. A facile approach to an integral determinant of formulation optimization is suggested, therefore, by these observations.
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Affiliation(s)
- C Surber
- Department of Dermatology, School of Medicine, University of California, San Francisco 94143
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Ogiso T, Shintani M. Mechanism for the enhancement effect of fatty acids on the percutaneous absorption of propranolol. J Pharm Sci 1990; 79:1065-71. [PMID: 2079652 DOI: 10.1002/jps.2600791206] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of a series of fatty acids on the percutaneous absorption of propranolol (PL) through rabbit skin and the mechanism by which fatty acids facilitate the skin penetration of PL were examined in vitro and in vivo using a gel base. Lauric and myristic acids, at the fatty acid:PL molar ratio of 1:1 were the most potent agents in increasing the skin penetration, giving the largest penetration rate (Js) and penetration coefficient (Kp) of PL. The molar ratio of 2:1 also exerted a large enhancing effect, comparable to that with a molar ratio of 1:1. When the enhancing effects of lauric acid, its amide, and its methyl ester were compared, the free acid gave the highest Js and Kp values. The plasma PL concentrations were significantly higher and more sustained after a single percutaneous application of the formulation with lauric acid than those after the formulation without the acid. The mechanism for the enhancing effect was examined by measuring IR and 13C NMR spectra, the solubility in buffer, and the apparent partition coefficient of PL. Additionally, the penetration of PL and lauric acid, as co-penetrants, through rabbit skin and shed snake skin were evaluated. The IR spectra of the mixture of PL with lauric acid (molar ratio, 1:1) was characterized by an extreme shift of the CO peak. Comparison of the NMR spectra of PL, lauric acid, and the mixture suggested that the carbonyl group of lauric acid interacted with the amino and hydroxyl groups of PL, probably by charge interaction.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T Ogiso
- Faculty of Pharmaceutical Sciences, Kinki University, Osaka, Japan
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