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Ambhore NS, Kalidhindi RSR, Sathish V. Sex-Steroid Signaling in Lung Diseases and Inflammation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1303:243-273. [PMID: 33788197 DOI: 10.1007/978-3-030-63046-1_14] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Sex/gender difference exists in the physiology of multiple organs. Recent epidemiological reports suggest the influence of sex-steroids in modulating a wide variety of disease conditions. Sex-based discrepancies have been reported in pulmonary physiology and various chronic inflammatory responses associated with lung diseases like asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, and rare lung diseases. Notably, emerging clinical evidence suggests that several respiratory diseases affect women to a greater degree, with increased severity and prevalence than men. Although sex-specific differences in various lung diseases are evident, such differences are inherent to sex-steroids, which are major biological variables in men and women who play a central role to control these differences. The focus of this chapter is to comprehend the sex-steroid biology in inflammatory lung diseases and to understand the mechanistic role of sex-steroids signaling in regulating these diseases. Exploring the roles of sex-steroid signaling in the regulation of lung diseases and inflammation is crucial for the development of novel and effective therapy. Overall, we will illustrate the importance of differential sex-steroid signaling in lung diseases and their possible clinical implications for the development of complementary and alternative medicine to treat lung diseases.
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Affiliation(s)
- Nilesh Sudhakar Ambhore
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo, ND, USA
| | | | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo, ND, USA.
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Ahmad N, Ahmad R, Mohammed Buheazaha T, Salman AlHomoud H, Al-Nasif HA, Sarafroz M. A comparative ex vivo permeation evaluation of a novel 5-Fluorocuracil nanoemulsion-gel by topically applied in the different excised rat, goat, and cow skin. Saudi J Biol Sci 2020; 27:1024-1040. [PMID: 32256163 PMCID: PMC7105695 DOI: 10.1016/j.sjbs.2020.02.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 01/05/2023] Open
Abstract
AIM OF THE STUDY 5-Fluorouracil (5-FU) can't be given orally because of very low bioavailability and produces serious adverse effects. Therefore, the main objective of this research is to develop, evaluate, and comparative effects by different nanoformulations of topical application on chemoprevention of skin cancer in different types of skin. MATERIAL AND METHODS Castor oil (oil), Transcutol HP (surfactant), and Polyethylene glycol (PEG)-400 (co-surfactant) have taken on the basis of nonionic property and highest nanoemulsion (NE)-region. Aqueous micro titration method with ultra-sonication method (based on high energy) was used for the preparation of 5-FU-NE. Optimized-5-FU-NE was stable thermodynamically, and their characterizations was performed on the basis of globule size, zeta potential, refractive index, and viscosity. Optimized-NE has been converted into 5-FU-NE-Gel with the help of Carbopol® 934 and also performed their permeation studies in the different skins (cow, goat, and rat, ex vivo) using Logan transdermal diffusion cell (DHC-6T). Optimized-5-FU-NE and 5-FU-NE-Gel were evaluated cytotoxic studies (in vitro) on the melanoma cell lines. RESULTS The permeation of 5-FU from 5-FU-NE-Gel nanoformulation for rat skin model was 1.56 times higher than the 5-FU-NE and 12.51 times higher than the 5-FU-S for the cow and goat skin model. The values of steady state flux and permeability coefficient for 5-FU-NE-Gel of rat skin were higher i.e. 12.0244 ± 1.12 µgcm-2h-1 and 1.2024 ± 0.073 × 10-2 µg cm-2h-1, respectively. Optimized-5-FU-NE and 5-FU-NE-Gel nanoformulation were found to be physically stable. SK-MEL-5 cancer cells have showed the results based on cytotoxicity studies (in vitro) that 5-FU as Optimized-5-FU-NE-Gel is much more efficacious than 5-FU-NE followed by free 5-FU. Localization of 5-FU from 5-FU-NE-Gel was higher with higher permeation in rat skin. CONCLUSION 5-FU-NE-Gel is found to be for the better to treatment of cutaneous malignancies. It can be developed 5-FU-NE-Gel could be a promising vehicle for the skin cancer chemoprevention.
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Key Words
- 5-FU, 5-Fluorouracil
- 5-FU-NE-Gel, 5-Fluorouracil Nanoemulsion Gel
- 5-Fluorouracil
- ANOVA, Analysis of variance
- BCS, Biopharmaceutical Classification System
- Cytotoxic activity
- DDTC, Diethyldithiocarbamate
- DSC, Differential Scanning Calorimetry
- Different skin permeation, chemoprevention
- Electrospray Ionization, ESI
- Er, Enhancement Ratio
- FT-IR, Fourier-transform infrared spectroscopy
- Kp, Permeability Coefficient
- Local accumulation efficiency
- NE, Nanoemulsion
- Nanoemulsion
- Nanoemulsion-gel
- PBS, phosphate buffered solution
- PDI, Polydispersity Index
- RI, Refractive index
- SEM, Scanning Electron Microscope
- TEM, Transmission Electron Microscope
- Transdermal delivery
- UHPLC-MS/MS, Ultra high performance liquid chromatography mass spectroscopy and mass spectroscopy
- ZP, Zeta Potential
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Affiliation(s)
- Niyaz Ahmad
- Department of Pharmaceutics, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
- Department of Pharmaceutical Chemistry, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Rizwan Ahmad
- Department of Natural Products and Alternative Medicine, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Taysser Mohammed Buheazaha
- Department of Pharmaceutics, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Hussain Salman AlHomoud
- Department of Pharmaceutics, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Hassan Ali Al-Nasif
- Department of Pharmaceutics, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Md Sarafroz
- Department of Pharmaceutical Chemistry, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Leoni G, Lyness A, Ginty P, Schutte R, Pillai G, Sharma G, Kemp P, Mount N, Sharpe M. Preclinical development of an automated injection device for intradermal delivery of a cell-based therapy. Drug Deliv Transl Res 2018; 7:695-708. [PMID: 28812281 PMCID: PMC5574955 DOI: 10.1007/s13346-017-0418-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Current methods for intradermal delivery of therapeutic products in clinical use include manual injection via the Mantoux technique and the use of injection devices, primarily developed for the delivery of vaccines and small molecules. A novel automated injection device is presented specifically designed for accurate delivery of multiple doses of product through a number of adjustable injection parameters, including injection depth, dose volume and needle insertion speed. The device was originally conceived for the delivery of a cell-based therapy to patients with skin wounds caused by epidermolysis bullosa. A series of preclinical studies was conducted (i) to evaluate the performance of the pre-production model (PreCTCDV01) and optimise the final design, (ii) to confirm that a cell therapy product can be effectively delivered through the injection system and (iii) to test whether the device can be safely and effectively operated by potential end-users. Results from these studies confirmed that the device is able to consistently deliver repeated doses of a liquid to the intradermal layer in an ex vivo skin model. In addition, the device can support delivery of a cell therapy product through a customised microbore tubing without compromising cell viability. Finally, the device was shown to be safe and easy to use as evidenced by usability testing. The clinical device has since been granted European market access and plans for clinical use are currently underway. The device is expected to find use in the emerging area of cell therapies and a broad spectrum of traditional parenteral drug delivery applications.
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Affiliation(s)
- Giulia Leoni
- Cell and Gene Therapy Catapult, 12th Floor Tower Wing, Guys Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Alex Lyness
- Centre for Biological Engineering, Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU, UK
| | - Patrick Ginty
- Cell and Gene Therapy Catapult, 12th Floor Tower Wing, Guys Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Rindi Schutte
- Cell and Gene Therapy Catapult, 12th Floor Tower Wing, Guys Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Gopalan Pillai
- Cell and Gene Therapy Catapult, 12th Floor Tower Wing, Guys Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Gayatri Sharma
- Cell and Gene Therapy Catapult, 12th Floor Tower Wing, Guys Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Paul Kemp
- Intercytex Ltd, 5 Vale Road, Stockport, SK6 3LE, UK
| | - Natalie Mount
- Cell and Gene Therapy Catapult, 12th Floor Tower Wing, Guys Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Michaela Sharpe
- Cell and Gene Therapy Catapult, 12th Floor Tower Wing, Guys Hospital, Great Maze Pond, London, SE1 9RT, UK.
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Mushak P. Gastro-Intestinal Absorption of Lead in Children and Adults: Overview of Biological and Biophysico-Chemical Aspects. CHEMICAL SPECIATION & BIOAVAILABILITY 2015. [DOI: 10.1080/09542299.1991.11083160] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Merchant HA, Afonso-Pereira F, Rabbie SC, Youssef SA, Basit AW. Gastrointestinal characterisation and drug solubility determination in animals. ACTA ACUST UNITED AC 2015; 67:630-9. [PMID: 25560785 DOI: 10.1111/jphp.12361] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/16/2014] [Indexed: 12/31/2022]
Abstract
OBJECTIVES To characterise the gastrointestinal (GI) environment in rat, rabbit and pig for the purpose of determining their utility as animal models for drug delivery in humans. METHODS GI fluid samples were characterised for osmolality, surface tension, pH and buffer capacity. The solubility of two model drugs, mesalazine (ionisable) and prednisolone (unionisable), were also measured and the results were correlated to the physicochemical fluid data. KEY FINDINGS The solubility of the ionisable drug mesalazine was positively correlated to the GI pH in all three species and was significantly influenced by the pH difference. In contrast, the solubility of the unionisable compound prednisolone was not correlated significantly to the changes in pH, buffer capacity, osmolality or surface tension. In general, the solubility of prednisolone was constant irrespective of the location of the sample in the gut from rabbit and pig; however, an unusual trend was observed for the solubility of prednisolone in rats. CONCLUSIONS The results suggest that solubility of ionisable drugs or pH-responsive formulations is significantly influenced by the differences in pH along the GI tract and inter-species differences. It was also found that the data on the GI solubility of prednisolone (a neutral compound) in rats might overestimate its true value in humans.
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Affiliation(s)
- Hamid A Merchant
- Department of Pharmaceutics, UCL School of Pharmacy, University College London, London, UK
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Chandra SA, Stokes AH, Hailey R, Merrill CL, Melich DH, DeSmet K, Furst SM, Peterson RA, Mellon-Kusibab K, Adler RR. Dermal toxicity studies: factors impacting study interpretation and outcome. Toxicol Pathol 2014; 43:474-81. [PMID: 25389277 DOI: 10.1177/0192623314548765] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The field of dermal toxicity continues to evolve in order to accurately predict dermal (and systemic) responses in humans to topically applied chemicals. Although the testing methods have undergone extensive refinements, idiosyncrasies and unexpected issues during the conduct of these studies are not unusual due to the plethora of new vehicles available for formulating test substances, changing regulatory requirements, and introducting new strain and/or species of laboratory animals as no single species or method seems to suffice for evaluating skin toxicity. The objective of this article is to illustrate some pragmatic issues that should be considered during the conduct as well as interpretation of dermal toxicity studies. Routine procedure-related issues such as hair clipping, tape stripping, and wrapping the animal's torso to prevent oral ingestion can influence the interpretation. Excipients used in dermal toxicity studies may be nontoxic when used alone but complex dermal formulations can result in unexpected irritation and toxicity. In conclusion, interpretation and risk assessment of dermal toxicity studies should be done in a comprehensive manner, taking into account procedure-related impact on study results, unique species susceptibility, limitation of gross visual (naked eye) observation for evidence of toxicity, and normal anatomical variation.
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Affiliation(s)
- Sundeep A Chandra
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Alan H Stokes
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Rick Hailey
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Christine L Merrill
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - David H Melich
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Kristina DeSmet
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Sylvia M Furst
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | - Richard A Peterson
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
| | | | - Rick R Adler
- Safety Assessment, GlaxoSmithKline, Research Triangle Park, North Carolina, USA
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Gupta V, Trivedi P. Ex vivo localization and permeation of cisplatin from novel topical formulations through excised pig, goat, and mice skin and in vitro characterization for effective management of skin-cited malignancies. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2014; 43:373-82. [PMID: 24628359 DOI: 10.3109/21691401.2014.893523] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT It would be advantageous to administer cisplatin topically for treatment of cutaneous malignancies. OBJECTIVES Present work focuses on ex vivo and in vitro characterization of proultraflexible topical formulations. MATERIALS AND METHODS Permeation of cisplatin through the excised pig, goat, and mice skin was quantitatively determined. RESULTS Data indicate that protransfersome carbopol gel (pcg) formulation clearly delayed drug permeation through skin. Permeation of cisplatin from protransfersome system (ps) formulation was enhanced by approximately 1.5 fold compared with pcg for pig and goat skin. DISCUSSION Localization of drug from pcg was higher and showed less permeation. CONCLUSION Cisplatin-loaded pcg formulation is better to treat cutaneous malignancies.
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Affiliation(s)
- Vandana Gupta
- a School of Pharmaceutical Sciences, Rajiv Gandhi Technical University , Gandhi Nagar, Bhopal , India
| | - Piyush Trivedi
- a School of Pharmaceutical Sciences, Rajiv Gandhi Technical University , Gandhi Nagar, Bhopal , India
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Alonso C, Martí M, Martínez V, Rubio L, Parra JL, Coderch L. Antioxidant cosmeto-textiles: Skin assessment. Eur J Pharm Biopharm 2013; 84:192-9. [DOI: 10.1016/j.ejpb.2012.12.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 11/12/2012] [Accepted: 12/07/2012] [Indexed: 01/18/2023]
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10
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Cohen-Avrahami M, Libster D, Aserin A, Garti N. Penetratin-induced transdermal delivery from HII mesophases of sodium diclofenac. J Control Release 2012; 159:419-28. [DOI: 10.1016/j.jconrel.2012.01.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 01/18/2012] [Accepted: 01/20/2012] [Indexed: 10/14/2022]
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11
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A combination of nonionic surfactants and iontophoresis to enhance the transdermal drug delivery of ondansetron HCl and diltiazem HCl. Eur J Pharm Biopharm 2012; 80:663-73. [DOI: 10.1016/j.ejpb.2011.11.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 11/03/2011] [Accepted: 11/10/2011] [Indexed: 11/18/2022]
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12
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Barbero AM, Frasch HF. Pig and guinea pig skin as surrogates for human in vitro penetration studies: A quantitative review. Toxicol In Vitro 2009; 23:1-13. [DOI: 10.1016/j.tiv.2008.10.008] [Citation(s) in RCA: 237] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 09/16/2008] [Accepted: 10/16/2008] [Indexed: 11/17/2022]
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Abstract
Significant differences that exist between the sexes affect the prevalence, incidence and severity of a broad range of diseases and conditions. Men and women also differ in their response to drug treatment. It is therefore essential to understand these reactions in order to appropriately conduct risk assessment and to design safe and effective treatments. Even from that modest perspective, how and when we use drugs can result in unwanted and unexpected outcomes. This review summarizes the sex-based differences that impact on pharmacokinetics, and includes a general comparison of clinical pharmacology as it applies to men, women and pregnant women. Sex-related or pregnancy-induced changes in drug absorption, distribution, metabolism and elimination, when significant, may guide changes in dosage regimen or therapeutic monitoring to increase its effectiveness or reduce potential toxicity. Given those parameters, and our knowledge of sex differences, we can derive essentially all factors necessary for therapeutic optimization. Since this is a rapidly evolving area, it is essential for the practitioner to review drug prescribing information and recent literature in order to fully understand the impact of these differences on clinical therapeutics.
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Affiliation(s)
- Offie P Soldin
- Departments of Medicine, Oncology and Physiology, Center for the Study of Sex Differences, Georgetown University Medical Center, Washington, DC, USA.
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Abstract
Risk assessment of xenobiotics using animal data involves extrapolation from high doses to low ones, and from animal species to humans. In some cases it also involves extrapolation from one route of exposure to another. To assess the risk of exposure to xenobiotics, information on both biokinetics and biodynamics are needed. The contribution of biokinetics to risk assessment is the subject of this review. The review includes the general aspects of biokinetics of chemicals, the models available to describe the biokinetic behaviour of a chemical and a discussion of the class of biokinetic models that is considered most suited for application to risk assessment: the physiologically-based biokinetic (PBBK) models. The power of PBBK models is illustrated with a few examples.
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Affiliation(s)
- P W van Vliet
- Health Council of The Netherlands, Rÿswÿk, The Netherlands
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15
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King JR, Riviere JE, Monteiro-Riviere NA. Characterization of lewisite toxicity in isolated perfused skin. Toxicol Appl Pharmacol 1992; 116:189-201. [PMID: 1412463 DOI: 10.1016/0041-008x(92)90298-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Lewisite (L) is a potent organic arsenical that causes rapid onset of pain and severe vesication on contact with epithelial tissues. The isolated perfused porcine skin flap (IPPSF) is an in vitro model that has shown potential as a model for cutaneous vesicant research. The objective of this study was to characterize IPPSF responses after topical exposure to six concentrations of L ranging from 0.07 to 5.0 mg/ml (n = 4/treatment plus controls). Biochemical markers of viability (glucose utilization (CGU) and lactate dehydrogenase (LDH) release), vascular resistance (VR), venous arsenic flux, and morphological parameters (light and electron microscopy) were evaluated. In addition, lewisite lesions were characterized at 1, 3, 5, and 8 hr after exposure (n = 4/time plus controls) using these morphological parameters, as well as enzyme histochemistry. Macroscopic and microscopic lesions caused by L exposure were dose related. Mild decreases in CGU were noted with the higher concentrations of L, while generally increased responses in LDH release and VR were seen. Marked increases in LDH activity were noted in the blister fluid of IPPSFs treated with 5.0 mg/ml of L. Also, significant cutaneous arsenic flux was noted at the 5.0 mg/ml dose of L. The formation of gross blisters, the location and characterization of epidermal-dermal junction separation, and the time course of lesion production paralleled the description of L-induced lesions in humans. The sensitivity of the IPPSF to L exposure and the similarity of lesions to those described for humans suggests that this model provides a relevant in vitro model with which to study mechanisms of chemical vesication and arsenic toxicity, as well as protective and therapeutic intervention for vesicant exposure.
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Affiliation(s)
- J R King
- Cutaneous Pharmacology and Toxicology Center, North Carolina State University, College of Veterinary Medicine, Raleigh 27606
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Powles P, Usansky JI, Franklin RA. The pharmacokinetics of pirtenidine in the rat and dog. Xenobiotica 1989; 19:1349-54. [PMID: 2618086 DOI: 10.3109/00498258909043186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. Pharmacokinetic studies on the topical antimicrobial agent, pirtenidine, have been conducted in male Sprague-Dawley rats and beagle dogs, using a validated h.p.l.c. method with u.v. detection to measure the drug in plasma. 2. Following a single i.v. bolus dose to the rat (equivalent to 1.35 mg base/kg) or dog (equivalent to 0.23 mg base/kg), the drug was extensively distributed with an apparent volume of distribution of 8.61/kg in rat and 3.31/kg in dog. Clearance was high (rat 2.71/h/kg; dog 1.51/kg) which resulted in a short terminal half-life in both species (2.2 and 1.5 h respectively). 3. Following a single oral dose to rats (equivalent to 4.5 mg base/kg) plasma pirtenidine concentrations were generally below the minimum quantifiable level of the analytical method (1 ng/ml). A maximum possible bioavailability of 0.3% was estimated. 4. After administering the same oral dose to dogs plasma concentrations rose slowly (t 1/2 abs = 1.2 h) to a peak (49.7 ng/ml) at 5.0 h post-dose. The terminal elimination half-life was 2.1 h. The absolute bioavailability was 10%.
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Affiliation(s)
- P Powles
- Sterling Research Group Europe, Alnwick Research Centre, Northumberland, UK
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Rietveld EC, Hoet RM, Seutter-Berlage F, Van Rossum JM. Percutaneous absorption of 14C-labelled 2-chlorobenzaldehyde in rats. Metabolism and toxicokinetics. Eur J Drug Metab Pharmacokinet 1988; 13:231-40. [PMID: 3243317 DOI: 10.1007/bf03190084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
2-Chlorobenzaldehyde might be produced when a moist skin is exposed to the riot control agent CS. CS-hydrolysis to 2-chlorobenzaldehyde and malononitrile occurs both in vitro and in vivo. No quantitative data have thus far been reported with respect to the percutaneous absorption and the cutaneous biotransformation of 2-chlorobenzaldehyde. Percutaneous absorption, biotransformation and elimination of 14-C-labelled 2-chlorobenzaldehyde was investigated in the rat. Following IV (25 microliters/kg) and IP (37.5 microliters/kg) 14C-2-chlorobenzaldehyde administration to rats, the plasma radioactivity declined rapidly over a 24 h period with similar plasma radioactivity-time profiles. Following cutaneous administration (75 microliters/kg) in a closed glass-cup on the skin a slow skin penetration occurred as indicated by plasma radioactivity levels. A slow increase in plasma radioactivity was followed by a slow decline of radioactivity in plasma over a 3-day period. Most of the radioactivity was found in the urine with low levels in faeces and exhaled air. The cutaneously administered radioactivity was also partly recovered from the glass-cup. For the qualitative and quantitative determination of metabolites in urine, a thin layer chromatography-radioautography method was used. The metabolic patterns of urinary excreted metabolites following cutaneous application and systemic administration of 14C-2-chlorobenzaldehyde to rats were very similar. No parent compound was recovered from the rat urine. 2-Chlorohippuric acid was the principal urinary metabolite. Quantitatively, the urinary excretion of 14C-2-chlorobenzyl alcohol following cutaneous application differed substantially from that after the systemic administration. There was no evidence of storage in the skin or skin toxicity of 2-chlorobenzaldehyde following cutaneous application.
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Affiliation(s)
- E C Rietveld
- Department of Pharmacology, Catholic University of Nijmegen, The Netherlands
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Abstract
Species differences are a major obstacle in predicting toxicity of xenobiotics from one species to another. Species differences in toxicity of drugs and other chemicals may be due to differences in pharmacokinetics or pharmacodynamics. This paper illustrates the point that species differences in pharmacokinetics of xenobiotics may be the result of differences in any of the processes contributing to the disposition of a xenobiotic. This is an important point because biotransformation as a cause of species differences for the disposition of xenobiotics has been overemphasized in the past, whereas only scant attention has been paid to the other 3 major contributing processes to disposition, viz. absorption, distribution, and excretion. This brief overview presents a balanced examination of all 4 major processes (absorption, distribution, biotransformation and excretion) as they affect the pharmacokinetics of xenobiotics in various species.
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Affiliation(s)
- K Rozman
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City 66103
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McCormack K, Brune K. Classical absorption theory and the development of gastric mucosal damage associated with the non-steroidal anti-inflammatory drugs. Arch Toxicol 1987; 60:261-9. [PMID: 3307703 DOI: 10.1007/bf01234664] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Evidence has accumulated during the last decade to support the view that the pharmacokinetic behaviour of non-steroidal anti-inflammatory drugs (NSAIDs) contributes not only decisively to their therapeutic effects but also to the type and incidence of their side effects. It has been shown that NSAIDs reach particularly high concentrations in those compartments in which they cause effects and side effects. Specifically, the data reviewed herein indicate that the accumulation of NSAID within gastric mucosal cells a priori is a principal factor associated with the intervention of intracellular biochemical events and resultant gastric mucosal damage. To a large extent this behaviour is according to the precepts of classical absorption theory; in this respect the limitations of such theory are examined. Our survey further indicates that the failure of certain NSAIDs to significantly reduce gastric mucosal levels of prostaglandins (PG) in vivo may reflect pharmacokinetic differences between NSAIDs rather than tissue-specific differences in their potency as inhibitors of cyclo-oxygenase.
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