Evaluation of a new topical skin protectant (RD1433) for the prevention and treatment of incontinence-associated dermatitis.

Context Incontinence-associated dermatitis (IAD) is a type of moisture-associated dermatitis caused by repeated skin exposure to urine or stool. A product that could mitigate such symptoms would have a significant impact on cost of care and patients' quality of life. Objective This study compared the clinical efficacy of RD1433 and a comparator product (Vaseline®) in preventing and treating experimental IAD skin lesions. Materials and methods For the "prevention" part of the study, skin sites in eight human volunteers were treated daily for 5 d with either RD1433 or Vaseline® immediately prior to synthetic urine exposure. In the "treatment" part, exposure to synthetic urine was substituted for Vaseline® or RD1433 application on the first 2 d to promote the development of skin lesions prior to the application of the products from day three. Product efficacy was quantified by visual scoring and an array of biophysical instruments. Results Both RD1433 and Vaseline® significantly reduced lesion progression when applied as a prophylactic. When applied as a treatment (following establishment of skin lesions), RD1433 demonstrated a statistically significant improvement in several measures of skin function whereas there was no statistically significant improvement following treatment with Vaseline®. Conclusions The findings of this study suggest that RD1433 may be superior to Vaseline® in the prevention and treatment of experimental IAD lesions. Clearly, further work is required to establish the efficacy of RD1433 with patients in a clinical environment.

Noninvasive in vivo magnetic resonance measures of glutathione synthesis in human and rat liver as an oxidative stress biomarker.

UNLABELLED: Oxidative stress (OS) plays a central role in the progression of liver disease and in damage to liver by toxic xenobiotics. We have developed methods for noninvasive assessment of hepatic OS defenses by measuring flux through the glutathione (GSH) synthesis pathway. (13) C-labeled GSH is endogenously produced and detected by in vivo magnetic resonance after administration of [2-(13) C]-glycine. We report on a successful first-ever human demonstration of this approach as well as preclinical studies demonstrating perturbed GSH metabolism in models of acute and chronic OS. Human studies employed oral administration of [2-(13) C]-glycine and (13) C spectroscopy on a 3T clinical magnetic resonance (MR) imaging scanner and demonstrated detection and quantification of endogenously produced (13) C-GSH after labeled glycine ingestion. Plasma analysis demonstrated that glycine (13) C fractional enrichment achieved steady state during the 6-hour ingestion period. Mean rate of synthesis of hepatic (13) C-labeled GSH was 0.32 ± 0.18 mmole/kg/hour. Preclinical models of acute OS and nonalcoholic steatohepatitis (NASH) comprised CCl4 -treated and high-fat, high-carbohydrate diet-fed Sprague-Dawley rats, respectively, using intravenous administration of [2-(13) C]-glycine and observation of (13) C-label metabolism on a 7T preclinical MR system. Preclinical studies demonstrated a 54% elevation of GSH content and a 31% increase in flux through the GSH synthesis pathway at 12 hours after acute insult caused by CCl4 administration, as well as a 23% decrease in GSH content and evidence of early steatohepatitis in the model of NASH. CONCLUSION: Our data demonstrate in vivo (13) C-labeling and detection of GSH as a biomarker of tissue OS defenses, detecting chronic and acute OS insults. The methods are applicable to clinical research studies of hepatic OS in disease states over time as well as monitoring effects of therapeutic interventions.