1
|
Chemical Permeation Enhancers for Topically-Applied Vitamin C and Its Derivatives: A Systematic Review. COSMETICS 2022. [DOI: 10.3390/cosmetics9040085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This paper reports the permeation-enhancing properties and safety of different chemical permeation enhancers (CPEs) on the topical delivery of vitamin C (VC) and its derivatives. A literature search using search keywords or phrases was done in PubMed®, ScienceDirect, and MEDLINE databases. The calculated Log P (cLog P) values were referenced from PubChem and the dermal LD50 values were referenced from safety data sheets. Thirteen studies described the permeation-enhancing activity of 18 identified CPEs in the topical delivery of VC. Correlation analysis between ER and cLog P values for porcine (r = 0.114) and rabbit (r = 0.471) showed weak and moderate positive correlation, while mouse (r = −0.135), and reconstructed human epidermis (r = −0.438) had a negative correlation. The majority (n = 17) of the CPEs belonged to Category 5 of the Globally Harmonized System of Classification or low toxicity hazard. CPEs alone or in combination enhanced permeation (ER = 0.198–106.57) of VC in topical formulations. The combination of isopropyl myristate, sorbitan monolaurate, and polyoxyethylene 80 as CPEs for VC resulted in the highest permeation enhancement ratio.
Collapse
|
2
|
Słoczyńska K, Popiół J, Gunia-Krzyżak A, Koczurkiewicz-Adamczyk P, Żmudzki P, Pękala E. Evaluation of Two Novel Hydantoin Derivatives Using Reconstructed Human Skin Model EpiskinTM: Perspectives for Application as Potential Sunscreen Agents. Molecules 2022; 27:molecules27061850. [PMID: 35335215 PMCID: PMC8949075 DOI: 10.3390/molecules27061850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 11/28/2022] Open
Abstract
This study aimed to assess two novel 5-arylideneimidazolidine-2,4-dione (hydantoin) derivatives (JH3 and JH10) demonstrating photoprotective activity using the reconstructed human skin model EpiskinTM. The skin permeability, irritation, and phototoxicity of the compounds was evaluated in vitro. Moreover, the in vitro genotoxicity and human metabolism of both compounds was studied. For skin permeation and irritation experiments, the test compounds were incorporated into a formulation. It was shown that JH3 and JH10 display no skin irritation and no phototoxicity. Both compounds did not markedly enhance the frequency of micronuclei in CHO-K1 cells in the micronucleus assay. Preliminary in vitro studies with liver microsomes demonstrated that hydrolysis appears to constitute their important metabolic pathway. EpiskinTM permeability experiments showed that JH3 permeability was lower than or close to currently used UV filters, whereas JH10 had the potential to permeate the skin. Therefore, a restriction of this compound permeability should be obtained by choosing the right vehicle or by optimizing it, which should be addressed in future studies.
Collapse
Affiliation(s)
- Karolina Słoczyńska
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland; (J.P.); (P.K.-A.); (E.P.)
- Correspondence: ; Tel.: +48-126-205-577
| | - Justyna Popiół
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland; (J.P.); (P.K.-A.); (E.P.)
| | - Agnieszka Gunia-Krzyżak
- Department of Bioorganic Chemistry, Chair of Organic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland;
| | - Paulina Koczurkiewicz-Adamczyk
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland; (J.P.); (P.K.-A.); (E.P.)
| | - Paweł Żmudzki
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland;
| | - Elżbieta Pękala
- Department of Pharmaceutical Biochemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland; (J.P.); (P.K.-A.); (E.P.)
| |
Collapse
|
3
|
Shahbaz M, Khan UA, Chaudhary MI, Yousuf S. A new bioactive cocrystal of coumarin-3-carboxylic acid and thiourea: detailed structural features and biological activity studies. Acta Crystallogr C Struct Chem 2022; 78:192-200. [PMID: 35245216 DOI: 10.1107/s205322962200081x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/23/2022] [Indexed: 11/10/2022] Open
Abstract
Cocrystallization is a phenomenon widely used to enhance the biological and physicochemical properties of active pharmaceutical ingredients (APIs). The present study deals with the synthesis of a cocrystal of coumarin-3-carboxylic acid (2-oxochromene-3-carboxylic acid, C10H6O4), a synthetic analogue of the naturally occurring antioxidant coumarin, with thiourea (CH4N2S) using the neat grinding method. The purity and homogeneity of the coumarin-3-carboxylic acid-thiourea (1/1) cocrystal was confirmed by single-crystal X-ray diffraction, FT-IR analysis and thermal stability studies based on differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Detailed geometry analysis via density functional theory (DFT) demonstrated that the 1:1 cocrystal stoichiometry is sustained by N-H...O hydrogen bonding between the amine (-NH2) groups of thiourea and the carbonyl group of coumarin. The synthesized cocrystal exhibited potent antioxidant activity (IC50 = 127.9 ± 5.95 µM) in a DPPH radical scavenger assay in vitro in comparison with the standard N-acetyl-L-cysteine (IC50 = 111.6 ± 2.4 µM). The promising results of the present study highlight the significance of cocrystallization as a crystal engineering tool to improve the efficacy of pharmaceutical ingredients.
Collapse
Affiliation(s)
- Muhammad Shahbaz
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Sindh 75270, Pakistan
| | - Umair Ahmed Khan
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Sindh 75270, Pakistan
| | - M Iqbal Chaudhary
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Sindh 75270, Pakistan
| | - Sammer Yousuf
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Sindh 75270, Pakistan
| |
Collapse
|
4
|
Effects of Natural Antioxidants on Phospholipid and Ceramide Profiles of 3D-Cultured Skin Fibroblasts Exposed to UVA or UVB Radiation. Antioxidants (Basel) 2021; 10:antiox10040578. [PMID: 33918064 PMCID: PMC8068794 DOI: 10.3390/antiox10040578] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 01/28/2023] Open
Abstract
Ultraviolet (UV) radiation is one of the primary factors responsible for disturbances in human skin cells phospholipid metabolism. Natural compounds that are commonly used to protect skin, due to their lipophilic or hydrophilic nature, show only a narrow range of cytoprotective activity, which prompts research on their combined application. Therefore, the aim of this study was to examine the effect of ascorbic acid and rutin on the phospholipid and ceramide profiles in UV-irradiated fibroblasts cultured in a three-dimensional system that approximates the culture conditions to the dermis. An ultra-high-performance liquid chromatograph coupled with a quadrupole time-of-flight mass spectrometer was used for phospholipid and ceramide profiling. As a result of UVA and UVB cells irradiation, upregulation of phosphatidylcholines, ceramides, and downregulation of sphingomyelins were observed, while treatment with ascorbic acid and rutin of UVA/UVB-irradiated fibroblast promoted these changes to provide cells a stronger response to stress. Moreover, an upregulation of phosphatidylserines in cells exposed to UVB and treated with both antioxidants suggests the stimulation of UV-damaged cells apoptosis. Our findings provide new insight into action of rutin and ascorbic acid on regulation of phospholipid metabolism, which improves dermis fibroblast membrane properties.
Collapse
|
5
|
Colorimetric quantification of α-tocopherol (vitamin E) in pure form and different comestible samples by using newly synthesized tetrazolium salts. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2020. [DOI: 10.1007/s13738-020-02038-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
6
|
Praça FG, Viegas JSR, Peh HY, Garbin TN, Medina WSG, Bentley MVLB. Microemulsion co-delivering vitamin A and vitamin E as a new platform for topical treatment of acute skin inflammation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 110:110639. [PMID: 32204073 DOI: 10.1016/j.msec.2020.110639] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/06/2019] [Accepted: 01/03/2020] [Indexed: 11/19/2022]
Abstract
In this study, we developed a water-in-oil microemulsion containing vitamin A (retinol) and vitamin E (α-tocopherol), which serves as a multifunctional nanosystem that co-delivers antioxidants and displayed additive effect against acute skin inflammation. Microemulsion (ME) was prepared by mixing a surfactant blend (Tween 80 and propylene glycol, 5:1) with isopropyl myristate and water (ratio of 50:40:10, respectively). Vitamin A (0.05% w/w concentration) and/or vitamin E (0.1% w/w concentration) were incorporated into the surfactant mixture of ME by stirring with a magnetic stirrer for 30 min. This multifunctional ME displayed physical stability, with low cytotoxicity in 3T3 cell line, as well as cellular internalization into the cytosol. In vivo treatments using ME delivering α-tocopherol reduced dermal expression of TNF-α by 1.3-fold (p < 0.01), when compared to unloaded ME treatment group. When retinol was added into the ME containing α-tocopherol, it further reduced TNF-α expression by 2-fold (p < 0.001), suggesting the additive effect of vitamin E and vitamin A in the treatment against skin inflammation. In conclusion, we successfully developed the use of water-in-oil ME to pack both vitamin E and vitamin A, and demonstrated for the first time its anti-inflammatory potential when applied topically to TPA-induced inflamed skin.
Collapse
Affiliation(s)
- Fabíola Garcia Praça
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Juliana Santos Rosa Viegas
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Hong Yong Peh
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | | | - Maria Vitoria Lopes Badra Bentley
- School of Pharmaceutical Sciences of Ribeirão Preto, Department of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| |
Collapse
|
7
|
Yu JR, Navarro J, Coburn JC, Mahadik B, Molnar J, Holmes JH, Nam AJ, Fisher JP. Current and Future Perspectives on Skin Tissue Engineering: Key Features of Biomedical Research, Translational Assessment, and Clinical Application. Adv Healthc Mater 2019; 8:e1801471. [PMID: 30707508 PMCID: PMC10290827 DOI: 10.1002/adhm.201801471] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Indexed: 12/20/2022]
Abstract
The skin is responsible for several important physiological functions and has enormous clinical significance in wound healing. Tissue engineered substitutes may be used in patients suffering from skin injuries to support regeneration of the epidermis, dermis, or both. Skin substitutes are also gaining traction in the cosmetics and pharmaceutical industries as alternatives to animal models for product testing. Recent biomedical advances, ranging from cellular-level therapies such as mesenchymal stem cell or growth factor delivery, to large-scale biofabrication techniques including 3D printing, have enabled the implementation of unique strategies and novel biomaterials to recapitulate the biological, architectural, and functional complexity of native skin. This progress report highlights some of the latest approaches to skin regeneration and biofabrication using tissue engineering techniques. Current challenges in fabricating multilayered skin are addressed, and perspectives on efforts and strategies to meet those limitations are provided. Commercially available skin substitute technologies are also examined, and strategies to recapitulate native physiology, the role of regulatory agencies in supporting translation, as well as current clinical needs, are reviewed. By considering each of these perspectives while moving from bench to bedside, tissue engineering may be leveraged to create improved skin substitutes for both in vitro testing and clinical applications.
Collapse
Affiliation(s)
- Justine R Yu
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
- University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Javier Navarro
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| | - James C Coburn
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- Division of Biomedical Physics, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, 20903, USA
| | - Bhushan Mahadik
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| | - Joseph Molnar
- Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - James H Holmes
- Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - Arthur J Nam
- Division of Plastic, Reconstructive and Maxillofacial Surgery, R. Adams Cowley Shock Trauma Center, University of Maryland, Baltimore, Baltimore, MD, 21201, USA
| | - John P Fisher
- Fischell Department of Bioengineering, University of Maryland, College Park, College Park, MD, 20742, USA
- NIH/NBIB Center for Engineering Complex Tissues, University of Maryland, College Park, College Park, MD, 20742, USA
| |
Collapse
|
8
|
In Vitro Models for Studying Transport Across Epithelial Tissue Barriers. Ann Biomed Eng 2018; 47:1-21. [DOI: 10.1007/s10439-018-02124-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/28/2018] [Indexed: 12/16/2022]
|
9
|
|
10
|
Application of standard cell cultures and 3D in vitro tissue models as an effective tool in drug design and development. Pharmacol Rep 2017. [DOI: 10.1016/j.pharep.2017.03.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
11
|
Spriggs S, Sheffield D, Olayanju A, Kitteringham NR, Naisbitt DJ, Aleksic M. Effect of Repeated Daily Dosing with 2,4-Dinitrochlorobenzene on Glutathione Biosynthesis and Nrf2 Activation in Reconstructed Human Epidermis. Toxicol Sci 2016; 154:5-15. [PMID: 27492222 DOI: 10.1093/toxsci/kfw140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Glutathione (GSH) plays a major role in skin detoxification processes due to its ability to conjugate electrophilic exogenous compounds with, and sometimes without, catalysis by glutathione-s-transferase (GST). GST activity has been demonstrated both in skin and in most in vitro skin equivalents but so far studies have focussed on chemical clearance (conjugate identification and rate of conjugation) and did not consider the GSH lifecycle (conjugation, recycling, synthesis). We used the model skin sensitizer 2,4-dinitrochlorobenzene (DNCB) to investigate the effects of chemical exposure on GSH lifecycle in reconstructed human epidermis (RHE). We demonstrated that the RHE model is suitable to carry out repeated cycles of 2-h exposure to DNCB over a 3-day period. After each exposure to DNCB, the level of GSH is diminished in a dose dependent manner. After a 22-h recovery period, GSH is replenished back to initial levels. Accumulation of the nuclear factor E2-related factor 2 (Nrf2) in the cytosol also occurs within the 2 h of exposure to DNCB but returns to baseline during each recovery period, demonstrating that activation of the Nrf2 signaling pathway offers a rapid response to chemical stress. The amount of dinitrophenyl-glutathione (DNP-SG) formed with DNCB (1) increased between the first and second exposure and (2) reached a plateau between the second and third exposure. Collectively, these data suggest that the metabolic capacity of skin may not be fixed in time but defence mechanisms might be activated in response to exposure to exogenous compounds, resulting in their accelerated clearance.
Collapse
Affiliation(s)
- Sandrine Spriggs
- *Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK;
| | - David Sheffield
- *Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK
| | - Adedamola Olayanju
- Department of Molecular and Clinical Pharmacology, MRC Centre for Drug Safety Science, the University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, UK
| | - Neil R Kitteringham
- Department of Molecular and Clinical Pharmacology, MRC Centre for Drug Safety Science, the University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, UK
| | - Dean J Naisbitt
- Department of Molecular and Clinical Pharmacology, MRC Centre for Drug Safety Science, the University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, UK
| | - Maja Aleksic
- *Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, UK
| |
Collapse
|
12
|
Ascenso A, Raposo S, Batista C, Cardoso P, Mendes T, Praça FG, Bentley MVLB, Simões S. Development, characterization, and skin delivery studies of related ultradeformable vesicles: transfersomes, ethosomes, and transethosomes. Int J Nanomedicine 2015; 10:5837-51. [PMID: 26425085 PMCID: PMC4583114 DOI: 10.2147/ijn.s86186] [Citation(s) in RCA: 173] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Ultradeformable vesicles (UDV) have recently become a promising tool for the development of improved and innovative dermal and transdermal therapies. The aim of this work was to study three related UDV: transfersomes, ethosomes, and transethosomes for the incorporation of actives of distinct polarities, namely, vitamin E and caffeine, and to evaluate the effect of the carrier on skin permeation and penetration. These actives were incorporated in UDV formulations further characterized for vesicles imaging by transmission electron microscopy; mean vesicle size and polydispersity index by photon correlation spectroscopy; zeta potential by laser-Doppler anemometry; deformability by pressure-driven transport; and incorporation efficiency (IE) after actives quantification by high-performance liquid chromatography. Topical delivery studies were performed in order to compare UDV formulations regarding the release, skin permeation, and penetration profiles. All UDV formulations showed size values within the expected range, except transethosomes prepared by “transfersomal method”, for which size was smaller than 100 nm in contrast to that obtained for vesicles prepared by “ethosomal method”. Zeta potential was negative and higher for formulations containing sodium cholate. The IE was much higher for vitamin E- than caffeine-loaded UDV as expected. For flux measurements, the following order was obtained: transethosomes (TE) > ethosomes (E) ≥ transfersomes (T). This result was consistent with the release and skin penetration profiles for Vitamin E-loaded UDV. However, the releasing results were totally the opposite for caffeine-loaded UDV, which might be explained by the solubility and thermodynamic activity of this active in each formulation instead of the UDV deformability attending to the higher non-incorporated fraction of caffeine. Anyway, a high skin penetration and permeation for all caffeine-loaded UDV were obtained. Transethosomes were more deformable than ethosomes and transfersomes due to the presence of both ethanol and surfactant in their composition. All these UDV were suitable for a deeper skin penetration, especially transethosomes.
Collapse
Affiliation(s)
- Andreia Ascenso
- Instituto de Investigação do Medicamento (iMed.ULisboa), Universidade de Lisboa, Lisboa, Portugal
| | - Sara Raposo
- Instituto de Investigação do Medicamento (iMed.ULisboa), Universidade de Lisboa, Lisboa, Portugal
| | - Cátia Batista
- Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - Pedro Cardoso
- Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - Tiago Mendes
- Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal
| | - Fabíola Garcia Praça
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Monte Alegre, Ribeirão Preto, São Paulo, Brazil
| | | | - Sandra Simões
- Instituto de Investigação do Medicamento (iMed.ULisboa), Universidade de Lisboa, Lisboa, Portugal
| |
Collapse
|
13
|
Froelich A, Osmałek T, Kunstman P, Roszak R, Białas W. Rheological and textural properties of microemulsion-based polymer gels with indomethacin. Drug Dev Ind Pharm 2015. [DOI: 10.3109/03639045.2015.1066799] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Anna Froelich
- Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Poznań, Poland and
| | - Tomasz Osmałek
- Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Poznań, Poland and
| | - Paweł Kunstman
- Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Poznań, Poland and
| | - Rafał Roszak
- Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Poznań, Poland and
| | - Wojciech Białas
- Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Poznań, Poland
| |
Collapse
|
14
|
Phospholipid Vesicle-Based Permeation Assay and EpiSkin® in Assessment of Drug Therapies Destined for Skin Administration. J Pharm Sci 2015; 104:1119-27. [DOI: 10.1002/jps.24315] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 11/23/2014] [Accepted: 12/02/2014] [Indexed: 01/01/2023]
|
15
|
Microemulsion system for topical delivery of thai mango seed kernel extract: development, physicochemical characterisation and ex vivo skin permeation studies. Molecules 2014; 19:17107-29. [PMID: 25347456 PMCID: PMC6271960 DOI: 10.3390/molecules191117107] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 10/16/2014] [Accepted: 10/17/2014] [Indexed: 11/17/2022] Open
Abstract
A microemulsion system containing Thai mango seed kernel extract (MSKE, cultivar “Fahlun”) was developed and characterised for the purpose of topical skin delivery. The MSKE-loaded microemulsions were prepared by using the spontaneous emulsification method. Isopropyl myristate (IPM) was selected as the oil phase. A polyoxyethylene sorbitan monooleate and sorbitan monododecanoate (1:1, w/w) system was used as the surfactant phase; an aqueous mixture of different cosurfactants (absolute ethanol, 96.3% v/v ethanol, 1-propanol, 2-propanol or 1,2-propanediol) at a weight ratio of 1:1 was used as the aqueous phase. Among the cosurfactants studied, the 1-propanol aqueous mixture had the largest microemulsion region (48.93%) in the pseudo-ternary phase diagram. Microemulsions containing 1% MSKE demonstrated good physicochemical stability during a six-month study period at 25 ± 2 °C/60% ± 5% RH. The ex vivo skin permeation study demonstrated that the microemulsions exhibited a potent skin enhancement effect allowing MSKE to penetrate skin layers up to 60-fold higher compared with the control. Neither skin irritation nor skin corrosion was observed in ex vivo studies. The present study revealed that IPM-based microemulsion systems may be promising carriers to enhance skin penetration and delivering MSKE for topical treatment.
Collapse
|
16
|
Sheraz MA, Khan MF, Ahmed S, Kazi SH, Khattak SR, Ahmad I. Factors affecting formulation characteristics and stability of ascorbic acid in water-in-oil creams. Int J Cosmet Sci 2014; 36:494-504. [DOI: 10.1111/ics.12152] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/25/2014] [Indexed: 12/01/2022]
Affiliation(s)
- M. A. Sheraz
- Baqai Institute of Pharmaceutical Sciences; Baqai Medical University; 51, Deh Tor, Toll Plaza, Super Highway, Gadap Road Karachi 74600 Pakistan
| | - M. F. Khan
- Baqai Institute of Pharmaceutical Sciences; Baqai Medical University; 51, Deh Tor, Toll Plaza, Super Highway, Gadap Road Karachi 74600 Pakistan
| | - S. Ahmed
- Baqai Institute of Pharmaceutical Sciences; Baqai Medical University; 51, Deh Tor, Toll Plaza, Super Highway, Gadap Road Karachi 74600 Pakistan
| | - S. H. Kazi
- Baqai Institute of Pharmaceutical Sciences; Baqai Medical University; 51, Deh Tor, Toll Plaza, Super Highway, Gadap Road Karachi 74600 Pakistan
| | - S. Rehman Khattak
- Central Drug Laboratories; Ministry of Health; Karachi 74400 Pakistan
| | - I. Ahmad
- Baqai Institute of Pharmaceutical Sciences; Baqai Medical University; 51, Deh Tor, Toll Plaza, Super Highway, Gadap Road Karachi 74600 Pakistan
| |
Collapse
|
17
|
Thomas S, Vieira CS, Hass MA, Lopes LB. Stability, cutaneous delivery, and antioxidant potential of a lipoic acid and α-tocopherol codrug incorporated in microemulsions. J Pharm Sci 2014; 103:2530-8. [PMID: 24961388 DOI: 10.1002/jps.24053] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/21/2014] [Accepted: 05/22/2014] [Indexed: 11/08/2022]
Abstract
The aim of this study was to assess the skin penetration, stability, and antioxidant effects of a α-tocopherol-lipoic acid codrug. To enhance penetration, we evaluated three microemulsions varying in water content and composition of the oil phase (isopropyl myristate with either monocaprylin or oleic acid). The codrug was incorporated at 1% (w/w). Codrug hydrolysis in the microemulsion increased with increases in time (up to 48 h) and formulation water content (10%-30%, w/w). Microemulsions increased the codrug delivery into viable layers of porcine ear skin by 2.9-7.8-fold compared with a control formulation (20% monocaprylin in isopropyl myristate) after 24 h. Penetration enhancement was influenced by the oil phase, with the formulation containing monocaprylin displaying the most pronounced effect. Antioxidant activity, assessed in skin bioequivalents using the thiobarbituric acid-reactive substances (TBARS) assay, demonstrated that TBARS levels decreased by 39% after treatment with the codrug-containing microemulsion compared with the unloaded formulation. In addition to the codrug, tocopherol (8.2 ± 0.6 μg/cm(2)) was detected in the viable bioequivalent tissues, suggesting that the codrug was partly hydrolyzed after 12 h. Taken together, these results support the potential of nanodispersed formulations containing a tocopherol-lipoic acid codrug to improve skin antioxidant activity.
Collapse
Affiliation(s)
- Siji Thomas
- Albany College of Pharmacy and Health Sciences, Albany, New York
| | | | | | | |
Collapse
|
18
|
Tfayli A, Bonnier F, Farhane Z, Libong D, Byrne HJ, Baillet-Guffroy A. Comparison of structure and organization of cutaneous lipids in a reconstructed skin model and human skin: spectroscopic imaging and chromatographic profiling. Exp Dermatol 2014; 23:441-3. [DOI: 10.1111/exd.12423] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Ali Tfayli
- Group of Analytical Chemistry of Paris-Sud (GCAPS); Faculty of Pharmacy; University Paris-Sud; Chatenay-Malabry France
| | - Franck Bonnier
- Focas Research Institute; Dublin Institute of Technology; Dublin 8 Ireland
| | - Zeineb Farhane
- Group of Analytical Chemistry of Paris-Sud (GCAPS); Faculty of Pharmacy; University Paris-Sud; Chatenay-Malabry France
| | - Danielle Libong
- Group of Analytical Chemistry of Paris-Sud (GCAPS); Faculty of Pharmacy; University Paris-Sud; Chatenay-Malabry France
| | - Hugh J. Byrne
- Focas Research Institute; Dublin Institute of Technology; Dublin 8 Ireland
| | - Arlette Baillet-Guffroy
- Group of Analytical Chemistry of Paris-Sud (GCAPS); Faculty of Pharmacy; University Paris-Sud; Chatenay-Malabry France
| |
Collapse
|
19
|
Lopes LB. Overcoming the cutaneous barrier with microemulsions. Pharmaceutics 2014; 6:52-77. [PMID: 24590260 PMCID: PMC3978525 DOI: 10.3390/pharmaceutics6010052] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/24/2014] [Accepted: 02/11/2014] [Indexed: 11/16/2022] Open
Abstract
Microemulsions are fluid and isotropic formulations that have been widely studied as delivery systems for a variety of routes, including the skin. In spite of what the name suggests, microemulsions are nanocarriers, and their use as topical delivery systems derives from their multiple advantages compared to other dermatological formulations, such as ease of preparation, thermodynamic stability and penetration-enhancing properties. Composition, charge and internal structure have been reported as determinant factors for the modulation of drug release and cutaneous and transdermal transport. This manuscript aims at reviewing how these and other characteristics affect delivery and make microemulsions appealing for topical and transdermal administration, as well as how they can be modulated during the formulation design to improve the potential and efficacy of the final system.
Collapse
Affiliation(s)
- Luciana B Lopes
- Institute of Biomedical Science, University of São Paulo, São Paulo 05508, SP, Brazil.
| |
Collapse
|
20
|
Cichewicz A, Pacleb C, Connors A, Hass MA, Lopes LB. Cutaneous delivery of α-tocopherol and lipoic acid using microemulsions: influence of composition and charge. ACTA ACUST UNITED AC 2013; 65:817-26. [PMID: 23647675 DOI: 10.1111/jphp.12045] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 01/15/2013] [Indexed: 01/12/2023]
Abstract
OBJECTIVES To assess whether the composition and charge of microemulsions affect their ability to simultaneously deliver α-tocopherol and lipoic acid into viable skin layers. METHODS α-Tocopherol and lipoic acid were added (1.1 and 0.5% w/w, respectively) to decylglucoside-based microemulsions containing mono-dicaprylin. Microemulsions containing surfactant : oil : water (w/w/w) at 60 : 30 : 10 (ME-O) and 46 : 23 : 31 (ME-W), as well as a cationic form of ME-W containing 1% phytosphingosine (ME-Wphy) were characterized, and their ability to disrupt the skin barrier and deliver the antioxidants in vitro in the skin was evaluated. Antioxidant activity in ME-Wphy-treated skin was assessed using the thiobarbituric acid-reactive substances (TBARS) assay. KEY FINDINGS The internal phase diameters of microemulsions ranged between 42 and 55 nm; phytosphingosine addition and pH adjustment to 5.0 increased zeta potential from -4.3 to +29.1 mV. ME-O displayed w/o structure, whereas ME-W and ME-Wphy were consistent with o/w. Microemulsions affected skin electrical resistance and transepidermal water loss, but did not affect lipoic acid penetration. α-Tocopherol delivery increased following the order ME-O < ME-W < ME-Wphy. ME-Wphy presented suitable short-term stability. The antioxidants delivered by ME-Wphy decreased TBARS cutaneous levels. CONCLUSIONS Even though microemulsion structure only affected tocopherol penetration, delivered levels of both antioxidants were sufficient for a decrease in TBARS, supporting their use for enhanced protection.
Collapse
Affiliation(s)
- Allie Cichewicz
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, 106 New Scotland Avenue, Albany, NY 12208, USA
| | | | | | | | | |
Collapse
|
21
|
|
22
|
Olejnik A, Goscianska J, Nowak I. Active compounds release from semisolid dosage forms. J Pharm Sci 2012; 101:4032-45. [PMID: 22886492 DOI: 10.1002/jps.23289] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 11/09/2022]
Abstract
The aim of this paper is to review all the aspects of the in vitro release testing (IVRT) from semisolid dosage forms. Although none of the official dissolution methods has been specified for use with semisolid dosage forms, their utility for assessing release rates of drugs from semisolid dosage forms has become a topic of considerable interest. One can expect to overcome such complexity in the future, when the official "Topical and Transdermal Drug Products-Product Performance Tests" will be published in an issue of the Pharmacopeial Forum. Many factors such as type of the dissolution medium, membrane, temperature, and speed have an influence on the mechanism and kinetics of the release testing from gels, creams, and ointments; therefore, those parameters have been widely discussed.
Collapse
Affiliation(s)
- Anna Olejnik
- Adam Mickiewicz University in Poznan, Faculty of Chemistry, ul. Umultowska 89b, 61-714 Poznań, Poland.
| | | | | |
Collapse
|
23
|
Valgimigli L, Gabbanini S, Berlini E, Lucchi E, Beltramini C, Bertarelli YL. Lemon (Citrus limon, Burm.f.) essential oil enhances the trans-epidermal release of lipid-(A, E) and water-(B6, C) soluble vitamins from topical emulsions in reconstructed human epidermis. Int J Cosmet Sci 2012; 34:347-56. [PMID: 22515469 DOI: 10.1111/j.1468-2494.2012.00725.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Topical bioavailability of lipid- and water-soluble vitamins is a critical issue for protecting or anti-ageing formulations. Using 17-day-old SkinEthic(®) reconstructed human epidermis, we investigated (at 34°C) the role of lemon EO in enhancing the penetration of α-tocopherol (E) and retinyl acetate (A), pyridoxine (B(6)) and ascorbic acid (C), released from O/W or W/O emulsions. D-limonene, α-pinene and p-cymene (65.9, 2.2 and 0.5%w/w of the oil) had skin permeability coefficients Ps (10(-3) cm h(-1)) of 0.56 ± 0.03 (or 0.73 ± 0.02), 0.72 ± 0.05 (or 0.98 ± 0.05) and 0.84 ± 0.04 (or 1.14 ± 0.04), respectively, when incorporated in a W/O (or O/W) emulsion. Vitamins B6, C and A had Ps values of (3.0 ± 0.4) × 10(-3), (7.9 ± 0.6) × 10(-3) and (0.37 ± 0.02) × 10(-5) cm h(-1), respectively, and their flux through the skin was enhanced by a factor of 4.1, 3.4 and 5.8, respectively, in the presence of lemon EO. The penetration of vitamin E was nine-fold enhanced. Lemon EO produced only reversible modification of TEWL, and it is a safe and effective penetration enhancer for topical administration of lipid- and water-soluble vitamins.
Collapse
Affiliation(s)
- L Valgimigli
- Department of Organic Chemistry, Faculty of Pharmacy, University of Bologna, Bologna, Italy.
| | | | | | | | | | | |
Collapse
|
24
|
Makpol S, Azura Jam F, Anum Mohd Yusof Y, Zurinah Wan Ngah W. Modulation of collagen synthesis and its gene expression in human skin fibroblasts by tocotrienol-rich fraction. Arch Med Sci 2011; 7:889-95. [PMID: 22291837 PMCID: PMC3258810 DOI: 10.5114/aoms.2011.25567] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 02/24/2011] [Accepted: 03/21/2011] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Skin aging may occur as a result of increased free radicals in the body. Vitamin E, the major chain-breaking antioxidant, prevents propagation of oxidative stress, especially in biological membranes. In this study, the molecular mechanism of tocotrienol-rich fraction (TRF) in preventing oxidative stress-induced skin aging was evaluated by determining the rate of total collagen synthesis and its gene expression in human skin fibroblasts. MATERIAL AND METHODS Primary culture of human skin fibroblasts was derived from circumcision foreskin of 9 to 12 year-old boys. Fibroblast cells were divided into 5 different treatment groups: untreated control, hydrogen peroxide (H(2)O(2))-induced oxidative stress (20 µM H(2)O(2) exposure for 2 weeks), TRF treatment, and pre- and post-treatment of TRF to H(2)O(2)-induced oxidative stress. RESULTS Our results showed that H(2)O(2)-induced oxidative stress decreased the rate of total collagen synthesis and down-regulated COL I and COL III in skin fibroblasts. Pre-treatment of TRF protected against H(2)O(2)-induced oxidative stress as shown by increase in total collagen synthesis and up-regulation of COL I and COL III (p<0.05) genes. However, similar protective effects against H(2)O(2)-induced oxidative stress were not observed in the post-treated fibroblasts. CONCLUSIONS Tocotrienol-rich fraction protects against H(2)O(2)-induced oxidative stress in human skin fibroblast culture by modulating the expression of COL I and COL III genes with concomitant increase in the rate of total collagen synthesis. These findings may indicate TRF protection against oxidative stress-induced skin aging.
Collapse
Affiliation(s)
- Suzana Makpol
- Department of Biochemistry, Faculty of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia
| | | | | | | |
Collapse
|
25
|
Gašperlin M, Gosenca M. Main approaches for delivering antioxidant vitamins through the skin to prevent skin ageing. Expert Opin Drug Deliv 2011; 8:905-19. [PMID: 21599565 DOI: 10.1517/17425247.2011.581657] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION One of the major contributions to skin photoageing and diseases is oxidative stress, caused by UV radiation inducing reactive oxygen and nitrogen species. Successful prophylaxis and therapy would necessitate control of the oxidant/antioxidant balance at the affected site, which can be achieved through the external supply of endogenous antioxidants. AREAS COVERED This review discusses possible strategies for dermal delivery of the antioxidant vitamins E and C, as oral supplementation has proved insufficient. These antioxidants have low skin bioavailability, owing to their poor solubility, inefficient skin permeability, or instability during storage. These drawbacks can be overcome by various approaches, such as chemical modification of the vitamins and the use of new colloidal drug delivery systems. New knowledge is included about the importance of: enhancing the endogenous skin antioxidant defense through external supply; the balance between various skin antioxidants; factors that can improve the skin bioavailability of antioxidants; and new delivery systems, such as microemulsions, used to deliver vitamins C and E into the skin simultaneously. EXPERT OPINION A promising strategy for enhancing skin protection from oxidative stress is to support the endogenous antioxidant system, with antioxidants containing products that are normally present in the skin.
Collapse
Affiliation(s)
- Mirjana Gašperlin
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000 Ljubljana, Slovenia.
| | | |
Collapse
|
26
|
Ito Y, Maeda T, Fukushima K, Sugioka N, Takada K. Permeation enhancement of ascorbic acid by self-dissolving micropile array tip through rat skin. Chem Pharm Bull (Tokyo) 2010; 58:458-63. [PMID: 20410623 DOI: 10.1248/cpb.58.458] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ascorbic acid (AA) loaded self-dissolving micropiles (SDMP) were prepared using chondroitin sulfate as the base for the percutaneous administration of AA. AA solution was added to dense solution of chondroitin solution, glue, and array tip, 1.0 cm(2), containing 100 SDMPs of which length was 500 microm and basal diameter was 300 microm, were prepared. Two kinds of AA array tips containing 1344.2+/-1.7 microg (high content ones) and 638.7+/-4.3 microg (low content ones) were used. In vitro dissolution study showed that more than 90% of AA were released from both SDMP array tips within 5 min. Stability experiment showed that 99.2-99.4% of AA was detected in SDMP array tips when stored at 23 degrees C for 1 week. When in vitro permeation experiments were performed after AA SDMP array was inserted to the isolated rat abdominal skin, extremely high amounts of AA, 1285.3+/-369.0 microg (95.3%) for high content SDMP tip and 405.6+/-84.3 microg (65.8%) for low content SDMP tip, were permeated for 6 h into the receptor compartment due to the break down of the skin barrier function. When AA SDMP array tip was administered to the rat skin under anesthetized condition with the different contact times, 10, 20 and 30 min, the permeated amount of AA was dependent on both the AA content in SDMP array tips and the contact time. When AA SDMP was contact to the skin for 30 min, permeated amounts of AA were 146.8+/-22.9 microg (10.9%) for high content-SDMP tip and 61.2+/-18.2 microg (9.6%) for low content SDMP tip. These results suggest the usefulness of SDMP array tip for the percutaneous absorption of AA.
Collapse
Affiliation(s)
- Yukako Ito
- Department of Pharmacokinetics, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto, Japan.
| | | | | | | | | |
Collapse
|
27
|
Salerno C, Carlucci AM, Bregni C. Study of in vitro drug release and percutaneous absorption of fluconazole from topical dosage forms. AAPS PharmSciTech 2010; 11:986-93. [PMID: 20521179 DOI: 10.1208/s12249-010-9457-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 05/13/2010] [Indexed: 11/30/2022] Open
Abstract
The present study aimed to evaluate different dosage forms, emulsions, emulgels, lipogels, and thickened microemulsion-based hydrogel, as fluconazole topical delivery systems with the purpose of determining a formulation with the capacity to deliver the whole active compound and maintain it within the skin so as to be considered a useful formulation either for topical mycosis treatment or as adjuvant in a combined therapy for Cutaneous Leishmaniasis. Propylene glycol and diethyleneglycol monoethyl ether were used for each dosage form as solvent for the drug and also as penetration enhancers. In vitro drug release after application of a clinically relevant dose of each formulation was evaluated and then microemulsions and lipogels were selected for the in vitro penetration and permeation study. Membranes of mixed cellulose esters and full-thickness pig ear skin were used for the in vitro studies. Candida albicans was used to test antifungal activity. A microemulsion containing diethyleneglycol monoethyl ether was found to be the optimum formulation as it was able to deliver the whole contained dose and enhance its skin penetration. Also this microemulsion showed the best performance in the antifungal activity test compared with the one containing propylene glycol. These results are according to previous reports of the advantages of microemulsions for topical administration and they are very promising for further clinical evaluation.
Collapse
|
28
|
Rozman B, Gosenca M, Gasperlin M, Padois K, Falson F. Dual influence of colloidal silica on skin deposition of vitamins C and E simultaneously incorporated in topical microemulsions. Drug Dev Ind Pharm 2010; 36:852-60. [DOI: 10.3109/03639040903541187] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
29
|
Zvonar A, Berginc K, Kristl A, Gašperlin M. Microencapsulation of self-microemulsifying system: Improving solubility and permeability of furosemide. Int J Pharm 2010; 388:151-8. [DOI: 10.1016/j.ijpharm.2009.12.055] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 12/18/2009] [Accepted: 12/24/2009] [Indexed: 12/29/2022]
|