The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
Michael S Roberts - One of the best experts on this subject based on the ideXlab platform.
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percutaneous absorption of Salicylates from some commercially available topical products containing methyl Salicylate or Salicylate salts in rats
Journal of Pharmacy and Pharmacology, 1995Co-Authors: S A Megwa, Heather A E Benson, Michael S RobertsAbstract:Studies to determine the extent of local tissue penetration of topically applied, commercially available Salicylate esters and salts were conducted in male Wistar rats. The Salicylate concentration in plasma, tissues underlying the site of drug application, and similar tissues on the contralateral (control) side were measured. The plasma and tissue Salicylate levels suggest that direct penetration of Salicylate was predominant to the top muscle level on the treated site. Results also suggest that the drugs were first absorbed into the bloodstream and subsequently distributed to both the deeper tissues on the treated site and the contralateral tissues. The topical application of formulations of ester methyl Salicylate and salts Triethanolamine Salicylate and diethylamine Salicylate containing comparable Salicylate concentrations yielded similar Salicylate concentrations in the various tissues. The Salicylate concentrations in the deeper tissues approached concentrations observed in the contralateral tissues suggesting that Salicylate present in these tissues was due to the systemic blood supply.
S A Megwa - One of the best experts on this subject based on the ideXlab platform.
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Self promotion of deep tissue penetration and distribution of methylSalicylate after topical application
'Springer Science and Business Media LLC', 1999Co-Authors: Se Cross, S A Megwa, Benson Hae, Roberts MsAbstract:Purpose. To determine how changes in cutaneous blood flow induced in-vivo by methylSalicylate (MeSA), compared to non-rubefacient Triethanolamine Salicylate (TSA), affected topical Salicylate absorption and distribution, and to assess formulation therapeutic potential by comparing tissue concentrations to published antiinflammatory concentrations. Methods. Flux of Salicylate from MeSA and TSA formulations applied to Full-thickness rat skin was determined using in vitro diffusion cells. Anaesthetised rats were then used to quantify Salicylate concentrations in plasma and tissues underlying the application site for the two formulations over a 6h period. In vitro and in vivo absorption profiles were then compared and the effect of MeSA on cutaneous blood flow assessed. Results. In vitro flux of Salicylate from the MeSA formulation was 40% higher, though after correcting for differences in formulation concentrations the ratio of permeability coefficients was reversed. Contrary to the in vitro predictions, in vivo tissue and plasma concentrations of Salicylate in rats rose rapidly in the first 1 hr and were more than the predicted 1.4-fold higher for MeSA. This effect was mirrored by the increase in blood flow induced by MeSA in human cutaneous vessels and that reported in the literature. Potential therapeutic levels were not seen below superficial muscle layers. Conclusions. Direct tissue penetration of Salicylate occurs below application sites from both MeSA and TSA formulations. Tissue concentrations of MeSA were higher than predicted due to its rapid distribution in the blood
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percutaneous absorption of Salicylates from some commercially available topical products containing methyl Salicylate or Salicylate salts in rats
Journal of Pharmacy and Pharmacology, 1995Co-Authors: S A Megwa, Heather A E Benson, Michael S RobertsAbstract:Studies to determine the extent of local tissue penetration of topically applied, commercially available Salicylate esters and salts were conducted in male Wistar rats. The Salicylate concentration in plasma, tissues underlying the site of drug application, and similar tissues on the contralateral (control) side were measured. The plasma and tissue Salicylate levels suggest that direct penetration of Salicylate was predominant to the top muscle level on the treated site. Results also suggest that the drugs were first absorbed into the bloodstream and subsequently distributed to both the deeper tissues on the treated site and the contralateral tissues. The topical application of formulations of ester methyl Salicylate and salts Triethanolamine Salicylate and diethylamine Salicylate containing comparable Salicylate concentrations yielded similar Salicylate concentrations in the various tissues. The Salicylate concentrations in the deeper tissues approached concentrations observed in the contralateral tissues suggesting that Salicylate present in these tissues was due to the systemic blood supply.
Heather A E Benson - One of the best experts on this subject based on the ideXlab platform.
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percutaneous absorption of Salicylates from some commercially available topical products containing methyl Salicylate or Salicylate salts in rats
Journal of Pharmacy and Pharmacology, 1995Co-Authors: S A Megwa, Heather A E Benson, Michael S RobertsAbstract:Studies to determine the extent of local tissue penetration of topically applied, commercially available Salicylate esters and salts were conducted in male Wistar rats. The Salicylate concentration in plasma, tissues underlying the site of drug application, and similar tissues on the contralateral (control) side were measured. The plasma and tissue Salicylate levels suggest that direct penetration of Salicylate was predominant to the top muscle level on the treated site. Results also suggest that the drugs were first absorbed into the bloodstream and subsequently distributed to both the deeper tissues on the treated site and the contralateral tissues. The topical application of formulations of ester methyl Salicylate and salts Triethanolamine Salicylate and diethylamine Salicylate containing comparable Salicylate concentrations yielded similar Salicylate concentrations in the various tissues. The Salicylate concentrations in the deeper tissues approached concentrations observed in the contralateral tissues suggesting that Salicylate present in these tissues was due to the systemic blood supply.
F M Plakogiannis - One of the best experts on this subject based on the ideXlab platform.
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assessment of Triethanolamine Salicylate release from the dermatological bases and the commercial products
Pharmaceutica Acta Helvetiae, 1991Co-Authors: A Babar, P J Chickhale, F M PlakogiannisAbstract:Recently, Triethanolamine Salicylate (TEAS) is frequently being incorporated in several over-the-counter topical analgesic pharmaceutical products. Since the clinical efficacy of such dosage form depends upon the release of the active ingredient at the site of application, the present study was undertaken to study the in vitro release of the (TEAS) from commonly used ointment bases and two most popular commercial products in the U.S. market. Also, the effects of various penetration enhancers, such as, ethanol, propylene glycol, polyethylene glycol-400, dimethyl-sulfoxide (DMSO), polysorbate-80 and urea were evaluated. In general, the drug release from the experimental formulations was higher than the commercial products studied. The inclusion of the penetration enhancing ingredients increased the drug release from some of the formulations evaluated. The hydrophilic emulsion base with 10% ethanol exhibited the best in vitro drug release. The apparent viscosity profiles of the formulations showed no definite relationship with the amounts of drug release. However, significant differences in the (TEAS) release from the experimental formulations were observed.
Se Cross - One of the best experts on this subject based on the ideXlab platform.
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Self promotion of deep tissue penetration and distribution of methylSalicylate after topical application
'Springer Science and Business Media LLC', 1999Co-Authors: Se Cross, S A Megwa, Benson Hae, Roberts MsAbstract:Purpose. To determine how changes in cutaneous blood flow induced in-vivo by methylSalicylate (MeSA), compared to non-rubefacient Triethanolamine Salicylate (TSA), affected topical Salicylate absorption and distribution, and to assess formulation therapeutic potential by comparing tissue concentrations to published antiinflammatory concentrations. Methods. Flux of Salicylate from MeSA and TSA formulations applied to Full-thickness rat skin was determined using in vitro diffusion cells. Anaesthetised rats were then used to quantify Salicylate concentrations in plasma and tissues underlying the application site for the two formulations over a 6h period. In vitro and in vivo absorption profiles were then compared and the effect of MeSA on cutaneous blood flow assessed. Results. In vitro flux of Salicylate from the MeSA formulation was 40% higher, though after correcting for differences in formulation concentrations the ratio of permeability coefficients was reversed. Contrary to the in vitro predictions, in vivo tissue and plasma concentrations of Salicylate in rats rose rapidly in the first 1 hr and were more than the predicted 1.4-fold higher for MeSA. This effect was mirrored by the increase in blood flow induced by MeSA in human cutaneous vessels and that reported in the literature. Potential therapeutic levels were not seen below superficial muscle layers. Conclusions. Direct tissue penetration of Salicylate occurs below application sites from both MeSA and TSA formulations. Tissue concentrations of MeSA were higher than predicted due to its rapid distribution in the blood
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Topical penetration of commercial Salicylate esters and salts using human isolated skin and clinical microdialysis studies
'Wiley', 1998Co-Authors: Se Cross, Anderson C, Roberts MsAbstract:Aims The penetration of active ingredients from topically applied anti-inflammatory pharmaceutical products into tissues below the skin is the basis of their therapeutic efficacy. There is still controversy as to whether these agents are capable of direct penetration by diffusion through the tissues or whether redistribution in the systemic circulation is responsible for their tissue deposition below the application site. Methods The extent of direct penetration of Salicylate from commercial ester and salt formulations into the dermal and subcutaneous tissue of human volunteers was determined using the technique of cutaneous microdialysis. We also examined differences in the extent of hydrolysis of the methylester of Salicylate applied topically in human volunteers and in vitro skin diffusion cells using full-thickness skin and epidermal membranes. Results The present study showed that whilst significant levels of Salicylate could be detected in the dermis and subcutaneous tissue of volunteers treated with the methylSalicylate formulation, negligible levels of Salicylate were seen following application of the Triethanolamine Salicylate formulation. The tissue levels of Salicylate from the methylSalicylate formulation were approx. 30-fold higher than the plasma concentrations. Conclusion The absorption and tissue concentration profiles for the commercial methylSalicylate formulation are indicative of direct tissue penetration and not solely redistribution by the systemic blood supply
