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Darvin ME. Optical Methods for Non-Invasive Determination of Skin Penetration: Current Trends, Advances, Possibilities, Prospects, and Translation into In Vivo Human Studies. Pharmaceutics 2023; 15:2272. [PMID: 37765241 PMCID: PMC10538180 DOI: 10.3390/pharmaceutics15092272] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/19/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
Information on the penetration depth, pathways, metabolization, storage of vehicles, active pharmaceutical ingredients (APIs), and functional cosmetic ingredients (FCIs) of topically applied formulations or contaminants (substances) in skin is of great importance for understanding their interaction with skin targets, treatment efficacy, and risk assessment-a challenging task in dermatology, cosmetology, and pharmacy. Non-invasive methods for the qualitative and quantitative visualization of substances in skin in vivo are favored and limited to optical imaging and spectroscopic methods such as fluorescence/reflectance confocal laser scanning microscopy (CLSM); two-photon tomography (2PT) combined with autofluorescence (2PT-AF), fluorescence lifetime imaging (2PT-FLIM), second-harmonic generation (SHG), coherent anti-Stokes Raman scattering (CARS), and reflectance confocal microscopy (2PT-RCM); three-photon tomography (3PT); confocal Raman micro-spectroscopy (CRM); surface-enhanced Raman scattering (SERS) micro-spectroscopy; stimulated Raman scattering (SRS) microscopy; and optical coherence tomography (OCT). This review summarizes the state of the art in the use of the CLSM, 2PT, 3PT, CRM, SERS, SRS, and OCT optical methods to study skin penetration in vivo non-invasively (302 references). The advantages, limitations, possibilities, and prospects of the reviewed optical methods are comprehensively discussed. The ex vivo studies discussed are potentially translatable into in vivo measurements. The requirements for the optical properties of substances to determine their penetration into skin by certain methods are highlighted.
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2
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Bielfeldt S, Bonnier F, Byrne H, Chourpa I, Dancik Y, Lane M, Lunter D, Munnier E, Puppels G, Tfayli A, Ziemons E. Monitoring dermal penetration and permeation kinetics of topical products; the role of Raman microspectroscopy. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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3
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Lunter D, Klang V, Kocsis D, Varga-Medveczky Z, Berkó S, Erdő F. Novel aspects of Raman spectroscopy in skin research. Exp Dermatol 2022; 31:1311-1329. [PMID: 35837832 PMCID: PMC9545633 DOI: 10.1111/exd.14645] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/07/2022] [Accepted: 07/12/2022] [Indexed: 11/27/2022]
Abstract
The analytical technology of Raman spectroscopy has an almost 100‐year history. During this period, many modifications and developments happened in the method like discovery of laser, improvements in optical elements and sensitivity of spectrometer and also more advanced light detection systems. Many types of the innovative techniques appeared (e.g. Transmittance Raman spectroscopy, Coherent Raman Scattering microscopy, Surface‐Enhanced Raman scattering and Confocal Raman spectroscopy/microscopy). This review article gives a short description about these different Raman techniques and their possible applications. Then, a short statistical part is coming about the appearance of Raman spectroscopy in the scientific literature from the beginnings to these days. The third part of the paper shows the main application options of the technique (especially confocal Raman spectroscopy) in skin research, including skin composition analysis, drug penetration monitoring and analysis, diagnostic utilizations in dermatology and cosmeto‐scientific applications. At the end, the possible role of artificial intelligence in Raman data analysis and the regulatory aspect of these techniques in dermatology are briefly summarized. For the future of Raman Spectroscopy, increasing clinical relevance and in vivo applications can be predicted with spreading of non‐destructive methods and appearance with the most advanced instruments with rapid analysis time.
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Affiliation(s)
- Dominique Lunter
- University of Tübingen, Department of Pharmaceutical Technology, Institute of Pharmacy and Biochemistry, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Victoria Klang
- University of Vienna, Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, Vienna, Austria
| | - Dorottya Kocsis
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, Budapest, Hungary
| | - Zsófia Varga-Medveczky
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, Budapest, Hungary
| | - Szilvia Berkó
- University of Szeged, Faculty of Pharmacy, Institute of Pharmaceutical Technology and Regulatory Affairs, Szeged, Hungary
| | - Franciska Erdő
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, Budapest, Hungary.,University of Tours EA 6295 Nanomédicaments et Nanosondes, Tours, France
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4
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Systematic Review on the Effectiveness of Essential and Carrier Oils as Skin Penetration Enhancers in Pharmaceutical Formulations. Sci Pharm 2022. [DOI: 10.3390/scipharm90010014] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Oils, including essential oils and their constituents, are widely reported to have penetration enhancement activity and have been incorporated into a wide range of pharmaceutical formulations. This study sought to determine if there is an evidence base for the selection of appropriate oils for particular applications and compare their effectiveness across different formulation types. A systematic review of the data sources, consisting of Google Scholar, EMBASE, PubMed, Medline, and Scopus, was carried out and, following screening and quality assessment, 112 articles were included within the analysis. The research was classified according to the active pharmaceutical ingredient, dosage form, in vitro/in vivo study, carrier material(s), penetration enhancers as essential oils, and other chemical enhancers. The review identified four groups of oils used in the formulation of skin preparations; in order of popularity, these are terpene-type essential oils (63%), fatty acid-containing essential oils (29%) and, finally, 8% of essential oils comprising Vitamin E derivatives and miscellaneous essential oils. It was concluded that terpene essential oils may have benefits over the fatty acid-containing oils, and their incorporation into advanced pharmaceutical formulations such as nanoemulsions, microemulsions, vesicular systems, and transdermal patches makes them an attractive proposition to enhance drug permeation through the skin.
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5
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Ruini C, Kendziora B, Ergun EZ, Sattler E, Gust C, French LE, Bağcı IS, Hartmann D. In vivo examination of healthy human skin after short-time treatment with moisturizers using confocal Raman spectroscopy and optical coherence tomography: Preliminary observations. Skin Res Technol 2021; 28:119-132. [PMID: 34555219 PMCID: PMC9907652 DOI: 10.1111/srt.13101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 07/31/2021] [Indexed: 11/28/2022]
Abstract
Skin is our barrier against environmental damage. Moisturizers are widely used to increase hydration and barrier integrity of the skin; however, there are contrasting observations on their in vivo effects in real-life settings. In cosmetic studies, corneometers and tewameters are traditionally used to assess skin hydration. In this study, two novel noninvasive diagnostic techniques, optical coherence tomography (OCT) and confocal Raman spectroscopy, were used to analyze stratum corneum and epidermal thickness (ET), water content, blood flow in function of depth, skin roughness, attenuation coefficient, natural moisturizing factor, ceramides and free fatty acids, cholesterol, urea, and lactates in 20 female subjects aged between 30 and 45 before and after 2 weeks application of a commercially available moisturizing lotion on one forearm. The untreated forearm served as control. A third measurement was conducted 1 week after cessation of moisturizing to verify whether the changes in the analyzed parameters persisted. We noticed a reduction in skin roughness, an increase in ceramides and free fatty acids and a not statistically significant increase in ET. As a conclusion, short time moisturizing appears insufficient to provide significant changes in skin morphology and composition, as assessed by OCT and RS. Novel noninvasive imaging methods are suitable for the evaluation of skin response to topical moisturizers. Further studies on larger sample size and longer treatment schedules are needed to analyze changes under treatment with moisturizers and to standardize the use of novel noninvasive diagnostic techniques.
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Affiliation(s)
- Cristel Ruini
- Department of Dermatology and Allergy, University Hospital, Ludwig Maximilian University, Munich, Germany.,PhD School in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - Benjamin Kendziora
- Department of Dermatology and Allergy, University Hospital, Ludwig Maximilian University, Munich, Germany
| | - Ecem Z Ergun
- Department of Dermatology and Allergy, University Hospital, Ludwig Maximilian University, Munich, Germany.,Istanbul Training and Research Hospital, Department of Dermatology, Istanbul, Turkey
| | - Elke Sattler
- Department of Dermatology and Allergy, University Hospital, Ludwig Maximilian University, Munich, Germany
| | - Charlotte Gust
- Department of Dermatology and Allergy, University Hospital, Ludwig Maximilian University, Munich, Germany
| | - Lars E French
- Department of Dermatology and Allergy, University Hospital, Ludwig Maximilian University, Munich, Germany.,Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Işın Sinem Bağcı
- Department of Dermatology, Stanford University, Stanford, California, USA
| | - Daniela Hartmann
- Department of Dermatology and Allergy, University Hospital, Ludwig Maximilian University, Munich, Germany
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6
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Zhang D, Bian Q, Zhou Y, Huang Q, Gao J. The application of label-free imaging technologies in transdermal research for deeper mechanism revealing. Asian J Pharm Sci 2020; 16:265-279. [PMID: 34276818 PMCID: PMC8261078 DOI: 10.1016/j.ajps.2020.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/23/2020] [Accepted: 07/06/2020] [Indexed: 12/13/2022] Open
Abstract
The penetration behavior of topical substances in the skin not only relates to the transdermal delivery efficiency but also involves the safety and therapeutic effect of topical products, such as sunscreen and hair growth products. Researchers have tried to illustrate the transdermal process with diversified theories and technologies. Directly observing the distribution of topical substances on skin by characteristic imaging is the most convincing approach. Unfortunately, fluorescence labeling imaging, which is commonly used in biochemical research, is limited for transdermal research for most topical substances with a molecular mass less than 500 Da. Label-free imaging technologies possess the advantages of not requiring any macromolecular dyes, no tissue destruction and an extensive substance detection capability, which has enabled rapid development of such technologies in recent years and their introduction to biological tissue analysis, such as skin samples. Through the specific identification of topical substances and endogenous tissue components, label-free imaging technologies can provide abundant tissue distribution information, enrich theoretical and practical guidance for transdermal drug delivery systems. In this review, we expound the mechanisms and applications of the most popular label-free imaging technologies in transdermal research at present, compare their advantages and disadvantages, and forecast development prospects.
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Affiliation(s)
- Danping Zhang
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Qiong Bian
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yi Zhou
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Qiaoling Huang
- The Third People's Hospital of Hangzhou, Hangzhou 310012, China
| | - Jianqing Gao
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Jiangsu Engineering Research Center for New-Type External and Transdermal Preparations, Changzhou 213000, China
- Corresponding author.
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7
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Pena AM, Chen X, Pence IJ, Bornschlögl T, Jeong S, Grégoire S, Luengo GS, Hallegot P, Obeidy P, Feizpour A, Chan KF, Evans CL. Imaging and quantifying drug delivery in skin - Part 2: Fluorescence andvibrational spectroscopic imaging methods. Adv Drug Deliv Rev 2020; 153:147-168. [PMID: 32217069 PMCID: PMC7483684 DOI: 10.1016/j.addr.2020.03.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 03/10/2020] [Accepted: 03/18/2020] [Indexed: 01/31/2023]
Abstract
Understanding the delivery and diffusion of topically-applied drugs on human skin is of paramount importance in both pharmaceutical and cosmetics research. This information is critical in early stages of drug development and allows the identification of the most promising ingredients delivered at optimal concentrations to their target skin compartments. Different skin imaging methods, invasive and non-invasive, are available to characterize and quantify the spatiotemporal distribution of a drug within ex vivo and in vivo human skin. The first part of this review detailed invasive imaging methods (autoradiography, MALDI and SIMS). This second part reviews non-invasive imaging methods that can be applied in vivo: i) fluorescence (conventional, confocal, and multiphoton) and second harmonic generation microscopies and ii) vibrational spectroscopic imaging methods (infrared, confocal Raman, and coherent Raman scattering microscopies). Finally, a flow chart for the selection of imaging methods is presented to guide human skin ex vivo and in vivo drug delivery studies.
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Affiliation(s)
- Ana-Maria Pena
- L'Oréal Research and Innovation, 1 avenue Eugène Schueller BP22, 93600 Aulnay-sous-Bois, France
| | - Xueqin Chen
- L'Oréal Research and Innovation, 1 avenue Eugène Schueller BP22, 93600 Aulnay-sous-Bois, France
| | - Isaac J Pence
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, CNY149-3, 13(th) St, Charlestown, MA 02129, United States of America
| | - Thomas Bornschlögl
- L'Oréal Research and Innovation, 1 avenue Eugène Schueller BP22, 93600 Aulnay-sous-Bois, France
| | - Sinyoung Jeong
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, CNY149-3, 13(th) St, Charlestown, MA 02129, United States of America
| | - Sébastien Grégoire
- L'Oréal Research and Innovation, 1 avenue Eugène Schueller BP22, 93600 Aulnay-sous-Bois, France.
| | - Gustavo S Luengo
- L'Oréal Research and Innovation, 1 avenue Eugène Schueller BP22, 93600 Aulnay-sous-Bois, France
| | - Philippe Hallegot
- L'Oréal Research and Innovation, 1 avenue Eugène Schueller BP22, 93600 Aulnay-sous-Bois, France
| | - Peyman Obeidy
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, CNY149-3, 13(th) St, Charlestown, MA 02129, United States of America
| | - Amin Feizpour
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, CNY149-3, 13(th) St, Charlestown, MA 02129, United States of America
| | - Kin F Chan
- Simpson Interventions, Inc., Woodside, CA 94062, United States of America
| | - Conor L Evans
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, CNY149-3, 13(th) St, Charlestown, MA 02129, United States of America.
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Carrer V, Alonso C, Pont M, Zanuy M, Córdoba M, Espinosa S, Barba C, Oliver MA, Martí M, Coderch L. Effect of propylene glycol on the skin penetration of drugs. Arch Dermatol Res 2019; 312:337-352. [PMID: 31786711 DOI: 10.1007/s00403-019-02017-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/31/2019] [Accepted: 11/20/2019] [Indexed: 12/12/2022]
Abstract
Propylene glycol (PG) has been used in formulations as a co-solvent and/or to enhance drug permeation through the skin from topical preparations. Two skin in vitro permeation approaches are used to determine the effect of PG on drug penetration. The in vitro Skin-PAMPA was performed using 24 actives applied in aqueous buffer or PG. PG modulates permeability by increasing or diminishing it in the compounds with poor or high permeability, respectively. Percutaneous absorption using pigskin on Franz diffusion cells was performed on seven actives and their commercial formulations. The commercial formulations evaluated tend to have a lower permeability than their corresponding PG solutions but maintain the compound distribution in the different strata: stratum corneum, epidermis and dermis. The results indicate the enhancer properties of PG for all compounds, especially for the hydrophilic ones. Additionally, the Synchrotron-Based Fourier Transform Infrared microspectroscopy technique is applied to study the penetration of PG and the molecular changes that the vehicle may promote in the different skin layers. Results showed an increase of the areas under the curve indicating the higher amount of lipids in the deeper layers and altering the lipidic order of the bilayer structure to a more disordered lipid structure.
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Affiliation(s)
- Victor Carrer
- Institute of Advanced Chemistry of Catalonia-CSIC (IQAC-CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain
| | - Cristina Alonso
- Institute of Advanced Chemistry of Catalonia-CSIC (IQAC-CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain.
| | - Mercè Pont
- Almirall R&D Center, Ctra. Laureà Miró 408-410, 08980, Sant Feliu de Llobregat, Barcelona, Spain
| | - Miriam Zanuy
- Almirall R&D Center, Ctra. Laureà Miró 408-410, 08980, Sant Feliu de Llobregat, Barcelona, Spain
| | - Mònica Córdoba
- Almirall R&D Center, Ctra. Laureà Miró 408-410, 08980, Sant Feliu de Llobregat, Barcelona, Spain
| | - Sonia Espinosa
- Almirall R&D Center, Ctra. Laureà Miró 408-410, 08980, Sant Feliu de Llobregat, Barcelona, Spain
| | - Clara Barba
- Institute of Advanced Chemistry of Catalonia-CSIC (IQAC-CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain
| | - Marc A Oliver
- Institute of Advanced Chemistry of Catalonia-CSIC (IQAC-CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain
| | - Meritxell Martí
- Institute of Advanced Chemistry of Catalonia-CSIC (IQAC-CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain
| | - Luisa Coderch
- Institute of Advanced Chemistry of Catalonia-CSIC (IQAC-CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain
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Human axillary skin condition is improved following incorporation of glycerol into the stratum corneum from an antiperspirant formulation. Arch Dermatol Res 2017; 309:739-748. [PMID: 28889318 DOI: 10.1007/s00403-017-1771-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/31/2017] [Accepted: 08/22/2017] [Indexed: 01/26/2023]
Abstract
The study objectives were to demonstrate that glycerol, when topically applied from a roll-on antiperspirant formulation, can be delivered directly to human skin ex vivo and the axillary stratum corneum (SC) in vivo, and to assess whether it improves the quality of the axillary skin barrier. Ex vivo human skin absorption of glycerol was measured following application of a roll-on antiperspirant formulation containing 4% 13C3-glycerol. Skin distribution of 13C3-glycerol over 24 h was assessed using gas chromatography-mass spectrometry. In vivo axillary SC penetration was measured by confocal Raman spectroscopy and multivariate curve-resolution software 1 h after topical application of a roll-on antiperspirant formulation containing 8% deuterated glycerol (d5-glycerol). A clinical study was conducted to determine the efficacy of a roll-on antiperspirant formulation containing 4% glycerol in reducing shaving-induced visual irritation and in increasing axillary-skin hydration. Ex vivo skin absorption studies indicated that the formulation delivered 13C3-glycerol into the SC at all timepoints over the 24-h period. In vivo Raman measurements (1 h after application) demonstrated that d5-glycerol was detectable to a depth of at least 10 μm in the axillary SC. Application of 4% glycerol from a roll-on antiperspirant formulation to the axilla was associated with significantly less visible irritation and greater skin hydration than observed with the control (glycerol-free) product. These studies demonstrate that glycerol, incorporated in a roll-on antiperspirant formulation, is delivered directly and rapidly to all depths of the axillary SC, and results in improvements in visible irritation and hydration in the axilla.
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Mujica Ascencio S, Choe C, Meinke MC, Müller RH, Maksimov GV, Wigger-Alberti W, Lademann J, Darvin ME. Confocal Raman microscopy and multivariate statistical analysis for determination of different penetration abilities of caffeine and propylene glycol applied simultaneously in a mixture on porcine skin ex vivo. Eur J Pharm Biopharm 2016; 104:51-8. [PMID: 27108784 DOI: 10.1016/j.ejpb.2016.04.018] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 01/05/2016] [Accepted: 04/20/2016] [Indexed: 01/07/2023]
Abstract
Propylene glycol is one of the known substances added in cosmetic formulations as a penetration enhancer. Recently, nanocrystals have been employed also to increase the skin penetration of active components. Caffeine is a component with many applications and its penetration into the epidermis is controversially discussed in the literature. In the present study, the penetration ability of two components - caffeine nanocrystals and propylene glycol, applied topically on porcine ear skin in the form of a gel, was investigated ex vivo using two confocal Raman microscopes operated at different excitation wavelengths (785nm and 633nm). Several depth profiles were acquired in the fingerprint region and different spectral ranges, i.e., 526-600cm(-1) and 810-880cm(-1) were chosen for independent analysis of caffeine and propylene glycol penetration into the skin, respectively. Multivariate statistical methods such as principal component analysis (PCA) and linear discriminant analysis (LDA) combined with Student's t-test were employed to calculate the maximum penetration depths of each substance (caffeine and propylene glycol). The results show that propylene glycol penetrates significantly deeper than caffeine (20.7-22.0μm versus 12.3-13.0μm) without any penetration enhancement effect on caffeine. The results confirm that different substances, even if applied onto the skin as a mixture, can penetrate differently. The penetration depths of caffeine and propylene glycol obtained using two different confocal Raman microscopes are comparable showing that both types of microscopes are well suited for such investigations and that multivariate statistical PCA-LDA methods combined with Student's t-test are very useful for analyzing the penetration of different substances into the skin.
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Affiliation(s)
- Saul Mujica Ascencio
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Centro de Investigación e Innovación Tecnológica (CIITEC) del Instituto Politécnico Nacional (IPN), Cerrada de Cecati S/N, Col. Santa Catarina Azcapotzalco, México D.F. CP: 02250, Mexico
| | - ChunSik Choe
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Kim Il Sung University, Ryongnam-Dong, Taesong District, Pyongyang, Democratic People's Republic of Korea
| | - Martina C Meinke
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Rainer H Müller
- Institute of Pharmacy, Department of Pharmaceutics, Biopharmaceutics & NutriCosmetics, Freie Universität Berlin, Kelchstraße 31, 12169 Berlin, Germany
| | - George V Maksimov
- M.V. Lomonosov Moscow State University, Department of Biophysics, Faculty of Biology, Leninskie Gory, 1-12, 119991 Moscow, Russia
| | | | - Juergen Lademann
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Maxim E Darvin
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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11
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Lunter DJ. How Confocal Is Confocal Raman Microspectroscopy on the Skin? Impact of Microscope Configuration and Sample Preparation on Penetration Depth Profiles. Skin Pharmacol Physiol 2016; 29:92-101. [PMID: 27054960 DOI: 10.1159/000444806] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/16/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS The aim of the study was to elucidate the effect of sample preparation and microscope configuration on the results of confocal Raman microspectroscopic evaluation of the penetration of a pharmaceutical active into the skin (depth profiling). METHODS Pig ear skin and a hydrophilic formulation containing procaine HCl were used as a model system. The formulation was either left on the skin during the measurement, or was wiped off or washed off prior to the analysis. The microscope configuration was varied with respect to objectives and pinholes used. RESULTS Sample preparation and microscope configuration had a tremendous effect on the results of depth profiling. Regarding sample preparation, the best results could be observed when the formulation was washed off the skin prior to the analysis. Concerning microscope configuration, the use of a 40 × 0.6 numerical aperture (NA) objective in combination with a 25-µm pinhole or a 100 × 1.25 NA objective in combination with a 50-µm pinhole was found to be advantageous. CONCLUSION Complete removal of the sample from the skin before the analysis was found to be crucial. A thorough analysis of the suitability of the chosen microscope configuration should be performed before acquiring concentration depth profiles.
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Affiliation(s)
- Dominique Jasmin Lunter
- Department of Pharmaceutical Technology, Faculty of Science, University of Tübingen, Tübingen, Germany
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12
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Hadgraft J, Lane ME. Drug crystallization - implications for topical and transdermal delivery. Expert Opin Drug Deliv 2016; 13:817-30. [PMID: 26766744 DOI: 10.1517/17425247.2016.1140146] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Crystallization of actives in skin following topical application was suggested by studies in the 1950s and 1960s but is poorly understood. In contrast, the problem of crystallization of actives on skin and in transdermal formulations has been known for many years. AREAS COVERED With respect to crystallization in skin, this review describes early reports of a skin 'reservoir' and possible reasons underlying its genesis. Techniques to study crystallization on and in skin and in transdermal patches are outlined. The role of the vehicle in skin delivery is emphasised. Studies which have investigated permeation from crystalline particles are described. Approaches to limit crystallization of actives are discussed. Using supersaturation and antinuclean polymers, control of crystal size is possible; controlled release from crystals is also employed in transdermal patches. EXPERT OPINION Drug crystallization has significant implications for topical and transdermal delivery. Approaches have been developed to counteract the issue for transdermal patches but crystallization in and on the skin for other formulations remains unresolved. Greater knowledge of residence time of excipients and their interaction with skin at the molecular level is critical in order to address the problem. This will lay the foundations for better design of topical/transdermal formulations.
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Affiliation(s)
- Jonathan Hadgraft
- a Department of Pharmaceutics , UCL School of Pharmacy , London , UK
| | - Majella E Lane
- a Department of Pharmaceutics , UCL School of Pharmacy , London , UK
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13
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Choe C, Lademann J, Darvin ME. Analysis of Human and Porcine Skin in vivo/ex vivo for Penetration of Selected Oils by Confocal Raman Microscopy. Skin Pharmacol Physiol 2015; 28:318-30. [PMID: 26418603 DOI: 10.1159/000439407] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/10/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND The subject of oil penetration into the skin is controversially discussed in the scientific literature. METHODS Confocal Raman microscopy was used for analyzing oil penetration into the skin. The following methods were applied in the study: methods based on tracking specific peaks (method 1), the nonrestricted multiple least square fit (method 2), analyzing the lipid-to-keratin peak ratio using the perpendicular drop-down cutoff procedure (method 3), and the Gaussian function-based deconvolution procedure (method 4). RESULTS The results obtained using methods 1, 2 and 4 show that the investigated oils do not penetrate deeper than 11 µm into human and porcine skin. Petrolatum has a prominent swelling effect on the stratum corneum (32% in vivo, 28% ex vivo), while the other oils exhibit no significant swelling effect. By using method 3, the penetration profile of oils, and especially of petrolatum, into the skin was interpreted incorrectly for various reasons that are addressed herein below. CONCLUSION Predominantly remaining in the uppermost corneocyte layers of the stratum corneum, topically applied oils do not reach the viable cells of the stratum spinosum. To exclude any possible mistakes when using the lipid-keratin Raman peak (2,820-3,030 cm-1), the penetration analysis should be performed using the Gaussian function-based deconvolution procedure.
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Affiliation(s)
- ChunSik Choe
- Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venereology and Allergology, Charitx00E9; - Universitx00E4;tsmedizin Berlin, Berlin, Germany
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Bonnist EYM, Pudney PDA, Weddell LA, Campbell J, Baines FL, Paterson SE, Matheson JR. Understanding the dandruff scalp before and after treatment: anin vivoRaman spectroscopic study. Int J Cosmet Sci 2014; 36:347-54. [DOI: 10.1111/ics.12132] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 03/29/2014] [Indexed: 11/29/2022]
Affiliation(s)
- E. Y. M. Bonnist
- Unilever R&D Colworth; Colworth Science Park, Sharnbrook Bedfordshire MK44 1LQ U.K
| | - P. D. A. Pudney
- Unilever R&D Colworth; Colworth Science Park, Sharnbrook Bedfordshire MK44 1LQ U.K
| | - L. A. Weddell
- Unilever R&D Port Sunlight; Quarry Rd East Bebington Wirral CH63 3JW U.K
| | - J. Campbell
- Unilever R&D Port Sunlight; Quarry Rd East Bebington Wirral CH63 3JW U.K
| | - F. L. Baines
- Unilever R&D Port Sunlight; Quarry Rd East Bebington Wirral CH63 3JW U.K
| | - S. E. Paterson
- Unilever R&D Port Sunlight; Quarry Rd East Bebington Wirral CH63 3JW U.K
| | - J. R. Matheson
- Unilever R&D Port Sunlight; Quarry Rd East Bebington Wirral CH63 3JW U.K
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Pudney PDA, Bonnist EYM, Mutch KJ, Nicholls R, Rieley H, Stanfield S. Confocal Raman spectroscopy of whole hairs. APPLIED SPECTROSCOPY 2013; 67:1408-1416. [PMID: 24359655 DOI: 10.1366/13-07086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This paper describes the application of Raman spectroscopy to whole hair fibers. Previously this has proved difficult because the hairs are relatively opaque, and spatial resolution diminishes with depth because of the change in refractive index. A solution is to couple confocal Raman with multivariate curve resolution (MCR) data analysis, which separates spectral differences with depth despite this reduction in resolution. Initially, it is shown that the cuticle can be separated from the cortex, showing the differences in the proteins, which can then be plotted as a function of depth, with the cuticle factor being seen only at the surface as expected. Hairs that had been treated in different ways, e.g., by bleaching, treatment with the active molecule resorcinol followed by rinsing and treatment with a full hair care product, were also examined. In all cases, changes to the hair are identified and are associated with specific parts of the fiber. Since the hair fiber is kept intact, it can be repeatedly treated and measured, hence multistep treatment processes can be followed. This method expands the potential use of Raman spectroscopy in hair research.
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Affiliation(s)
- Paul D A Pudney
- Unilever Discover, Colworth Laboratory, Sharnbrook, Bedfordshire, MK44 1LQ UK
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Lane ME. Skin penetration enhancers. Int J Pharm 2013; 447:12-21. [DOI: 10.1016/j.ijpharm.2013.02.040] [Citation(s) in RCA: 413] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/15/2013] [Accepted: 02/17/2013] [Indexed: 01/09/2023]
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