1
|
Heard CM. An ex vivo skin model to probe modulation of local cutaneous arachidonic acid inflammation pathway. J Biol Methods 2020; 7:e138. [PMID: 33204741 PMCID: PMC7666330 DOI: 10.14440/jbm.2020.319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 05/15/2020] [Accepted: 05/17/2020] [Indexed: 02/02/2023] Open
Abstract
There is a need for inexpensive and reliable means to determine the modulation of cutaneous inflammation. The method outlined in this article draws together a number of scientific techniques and makes use of generally unwanted biological tissues as a means of determining skin inflammation ex vivo, and focuses on probing aspects of the arachidonic acid inflammation pathway. Freshly excised skin contains elevated levels of short-lived inducible cyclooxygenase-2 (COX-2) and, under viable conditions, COX-2 and its eicosanoid products will continue to be produced until tissue necrosis, providing a window of time in which relative levels can be probed to determine exacerbation due to an upregulating factor or downregulation due the presence of an agent exerting anti-inflammatory activity. Ex vivo porcine skin, mounted in Franz diffusion cells, is dosed topically with the xenobiotic challenge and then techniques such as Western blotting and immunohistochemistry can then be used to probe relative COX-2 levels on a semi-quantitative or qualitative level. Enzyme-linked immunosorbent assay or LCMS can be used to determine relative prostaglandin E-2 (PGE-2) levels. Thus far, the technique has been used to examine the effects of topically applied anti-inflammatories (betamethasone, ibuprofen, ketoprofen and methotrexate), natural products (fish oil, Devil’s claw extract and pomegranate rind extract) and drug delivery vehicle (polyNIPAM nanogels). Topically applied xenobiotics that modulate factors such as COX-2 and PGE-2 must penetrate the intact skin, and this provides direct evidence of overcoming the "barrier function" of the stratum corneum in order to target the viable epidermis in sufficient levels to be able to elicit such effects. This system has particular potential as a pre-clinical screening tool for those working on the development of topical delivery systems, and has the additional advantage of being in line with 3 Rs philosophy.
Collapse
Affiliation(s)
- Charles M Heard
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3 NB Wales, United Kingdom
| |
Collapse
|
2
|
Zulfakar MH, Chan LM, Rehman K, Wai LK, Heard CM. Coenzyme Q10-Loaded Fish Oil-Based Bigel System: Probing the Delivery Across Porcine Skin and Possible Interaction with Fish Oil Fatty Acids. AAPS PharmSciTech 2018; 19:1116-1123. [PMID: 29181705 DOI: 10.1208/s12249-017-0923-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/13/2017] [Indexed: 01/25/2023] Open
Abstract
Coenzyme Q10 (CoQ10) is a vitamin-like oil-soluble molecule that has anti-oxidant and anti-ageing effects. To determine the most optimal CoQ10 delivery vehicle, CoQ10 was solubilised in both water and fish oil, and formulated into hydrogel, oleogel and bigel. Permeability of CoQ10 from each formulation across porcine ear skin was then evaluated. Furthermore, the effects of the omega-3 fatty eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids from fish oil on skin permeation were investigated by means of nuclear magnetic resonance (NMR) and computerised molecular modelling docking experiments. The highest drug permeation was achieved with the bigel formulation that proved to be the most effective vehicle in delivering CoQ10 across the skin membrane due to a combination of its adhesive, viscous and lipophilic properties. Furthermore, the interactions between CoQ10 and fatty acids revealed by NMR and molecular modelling experiments likely accounted for skin permeability of CoQ10. NMR data showed dose-dependent changes in proton chemical shifts in EPA and DHA. Molecular modelling revealed complex formation and large binding energies between fatty acids and CoQ10. This study advances the knowledge about bigels as drug delivery vehicles and highlights the use of NMR and molecular docking studies for the prediction of the influence of drug-excipient relationships at the molecular level.
Collapse
|
3
|
Houston DMJ, Bugert J, Denyer SP, Heard CM. Anti-inflammatory activity of Punica granatum L. (Pomegranate) rind extracts applied topically to ex vivo skin. Eur J Pharm Biopharm 2016; 112:30-37. [PMID: 27867111 DOI: 10.1016/j.ejpb.2016.11.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/11/2016] [Accepted: 11/14/2016] [Indexed: 11/26/2022]
Abstract
Coadministered pomegranate rind extract (PRE) and zinc (II) produces a potent virucidal activity against Herpes simplex virus (HSV); however, HSV infections are also associated with localised inflammation and pain. Here, the objective was to determine the anti-inflammatory activity and relative depth penetration of PRE, total pomegranate tannins (TPT) and zinc (II) in skin, ex vivo. PRE, TPT and ZnSO4 were dosed onto freshly excised ex vivo porcine skin mounted in Franz diffusion cells and analysed for COX-2, as a marker for modulation of the arachidonic acid inflammation pathway, by Western blotting and immunohistochemistry. Tape stripping was carried out to construct relative depth profiles. Topical application of PRE to ex vivo skin downregulated expression of COX-2, which was significant after just 6h, and maintained for up to 24h. This was achieved with intact stratum corneum, proving that punicalagin penetrated skin, further supported by the depth profiling data. When PRE and ZnSO4 were applied together, statistically equal downregulation of COX-2 was observed when compared to the application of PRE alone; no effect followed the application of ZnSO4 alone. TPT downregulated COX-2 less than PRE, indicating that tannins alone may not be entirely responsible for the anti-inflammatory activity of PRE. Punicalagin was found throughout the skin, in particular the lower regions, indicating appendageal delivery as a significant route to the viable epidermis. Topical application of TPT and PRE had significant anti-inflammatory effects in ex vivo skin, confirming that PRE penetrates the skin and modulates COX-2 regulation in the viable epidermis. Pomegranates have potential as a novel approach in ameliorating the inflammation and pain associated with a range of skin conditions, including cold sores and herpetic stromal keratitis.
Collapse
Affiliation(s)
- David M J Houston
- School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, Wales, United Kingdom; Department of Microbiology & Infectious Diseases, School of Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
| | - Joachim Bugert
- Department of Microbiology & Infectious Diseases, School of Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom; Institute of Microbiology, Armed Forces Medical Academy, Neuherbergstraβe 11, 80937 München, Germany
| | - Stephen P Denyer
- School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, Wales, United Kingdom; University of Brighton, Mithras House, Lewes Road, Brighton BN2 4AT, United Kingdom
| | - Charles M Heard
- School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, Wales, United Kingdom.
| |
Collapse
|
4
|
Novel Fish Oil-based Bigel System for Controlled Drug Delivery and its Influence on Immunomodulatory Activity of Imiquimod Against Skin Cancer. Pharm Res 2016; 34:36-48. [DOI: 10.1007/s11095-016-2036-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/01/2016] [Indexed: 10/21/2022]
|
5
|
Probing the effects of fish oil on the delivery and inflammation-inducing potential of imiquimod. Int J Pharm 2015; 490:131-41. [DOI: 10.1016/j.ijpharm.2015.05.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/17/2015] [Accepted: 05/17/2015] [Indexed: 02/05/2023]
|
6
|
Rehman K, Mohd Amin MCI, Zulfakar MH. Development and Physical Characterization of Polymer-Fish Oil Bigel (Hydrogel/Oleogel) System as a Transdermal Drug Delivery Vehicle. J Oleo Sci 2014; 63:961-70. [DOI: 10.5650/jos.ess14101] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
7
|
Lau WM, Heard CM, White AW. Design, synthesis and in vitro degradation of a novel co-drug for the treatment of psoriasis. Pharmaceutics 2013; 5:232-45. [PMID: 24300448 PMCID: PMC3834954 DOI: 10.3390/pharmaceutics5020232] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/01/2013] [Accepted: 04/10/2013] [Indexed: 12/20/2022] Open
Abstract
Psoriasis is a common, chronic and relapsing inflammatory skin disease. It affects approximately 2% of the western population and has no cure. Combination therapy for psoriasis often proves more efficacious and better tolerated than monotherapy with a single drug. Combination therapy could be administered in the form of a co-drug, where two or more therapeutic compounds active against the same condition are linked by a cleavable covalent bond. Similar to the pro-drug approach, the liberation of parent moieties post-administration, by enzymatic and/or chemical mechanisms, is a pre-requisite for effective treatment. In this study, a series of co-drugs incorporating dithranol in combination with one of several non-steroidal anti-inflammatory drugs, both useful for the treatment of psoriasis, were designed, synthesized and evaluated. An ester co-drug comprising dithranol and naproxen in a 1:1 stoichiometric ratio was determined to possess the optimal physicochemical properties for topical delivery. The co-drug was fully hydrolyzed in vitro by porcine liver esterase within four hours. When incubated with homogenized porcine skin, 9.5% of the parent compounds were liberated after 24 h, suggesting in situ esterase-mediated cleavage of the co-drug would occur within the skin. The kinetics of the reaction revealed first order kinetics, Vmax = 10.3 μM·min-1 and Km = 65.1 μM. The co-drug contains a modified dithranol chromophore that was just 37% of the absorbance of dithranol at 375 nm and suggests reduced skin/clothes staining. Overall, these findings suggest that the dithranol-naproxen co-drug offers an attractive, novel approach for the treatment of psoriasis.
Collapse
Affiliation(s)
- Wing Man Lau
- School of Pharmacy, University of Reading, Whiteknights, P.O. Box 226, Reading, RG6 6AP, UK
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK; E-Mails: (C.M.H.); (A.W.W.)
| | - Charles M. Heard
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK; E-Mails: (C.M.H.); (A.W.W.)
| | - Alex W. White
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB, UK; E-Mails: (C.M.H.); (A.W.W.)
| |
Collapse
|
8
|
Lau WM, White AW, Heard CM. Topical delivery of a naproxen-dithranol co-drug: in vitro skin penetration, permeation, and staining. Pharm Res 2010; 27:2734-42. [PMID: 20872052 DOI: 10.1007/s11095-010-0274-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 09/09/2010] [Indexed: 12/25/2022]
Abstract
PURPOSE This work probed the topical delivery and skin-staining properties of a novel co-drug, naproxyl-dithranol (Nap-DTH), which comprises anti-inflammatory (naproxen) and anti-proliferative (dithranol) moieties. METHOD Freshly excised, full-thickness porcine ear skin was dosed with saturated solutions of the compounds. After 24 h, the skin was recovered and used to prepare comparative depth profiles by the tape-stripping technique and to examine the extent of skin staining. RESULTS Depth profiles showed that Nap-DTH led to a 5-fold increase in drug retention in the skin compared to dithranol. The application of Nap-DTH also demonstrated improved stability, resulting in lower levels of dithranol degradation products in the skin. Furthermore, significantly less naproxen from hydrolysed Nap-DTH permeated into the receptor phase compared to naproxen when applied alone (0.08 ± 0.03 nmol cm(-)² and 180 ± 60 nmol cm(-)², respectively). Moreover, the reduced staining of the skin was very apparent for Nap-DTH compared to dithranol. CONCLUSIONS Topical delivery of Nap-DTH not only improves the delivery of naproxen and dithranol, but also reduces unwanted effects of the parent moieties, in particular the skin staining, which is a major issue concerning the use of dithranol.
Collapse
Affiliation(s)
- Wing Man Lau
- Welsh School of Pharmacy, Cardiff University, Cardiff, UK.
| | | | | |
Collapse
|
9
|
Enhanced topical delivery and ex vivo anti-inflammatory activity from a betamethasone dipropionate formulation containing fish oil. Inflamm Res 2009; 59:23-30. [DOI: 10.1007/s00011-009-0065-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 06/25/2009] [Accepted: 06/29/2009] [Indexed: 11/25/2022] Open
|
10
|
Morris AP, Brain KR, Heard CM. Skin permeation and ex vivo skin metabolism of O-acyl haloperidol ester prodrugs. Int J Pharm 2008; 367:44-50. [PMID: 18845232 DOI: 10.1016/j.ijpharm.2008.09.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 09/05/2008] [Accepted: 09/09/2008] [Indexed: 10/21/2022]
Abstract
Ethyl (HE), propyl (HP), butyl (HB), octyl (HO) and decyl (HD) O-acyl esters of haloperidol (HA) were evaluated for permeation across full-thickness human and guinea pig skin. The inclusion of 0.5mgmL(-1) cetrimide as a receptor phase solubilising agent did not significantly alter the barrier properties of the membranes. The permeation of the parent drug, HA, across guinea pig skin was found to be greater than that of its derivatives. Prodrug hydrolysis by cutaneous esterases was minimal. The permeation of HE, HP and HB across freshly excised guinea pig skin was subsequently investigated, however, prodrug hydrolysis remained low. Hydrolysis studies using a skin extract revealed only limited prodrug metabolism. However, in the presence of a liver extract, hydrolysis of all prodrugs was rapid. It was proposed that GGGX esterases, required for the hydrolysis of tertiary esters, were not present at a sufficiently high concentration within the skin for substantial prodrug hydrolysis to occur. This does not necessarily detract from the system as post-transdermal delivery liberation of HA in vivo is an equally useful mode for delivering this drug to the systemic circulation.
Collapse
Affiliation(s)
- Andrew P Morris
- Welsh School of Pharmacy, Cardiff University, Cardiff CF10 3NB, UK
| | | | | |
Collapse
|
11
|
Abdulmajed K, Heard CM. Topical Delivery of Retinyl Ascorbate. Skin Pharmacol Physiol 2008; 21:46-9. [DOI: 10.1159/000111135] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Accepted: 07/23/2007] [Indexed: 11/19/2022]
|