Introduction: Transdermal patches and medicated plasters (patch) represent well-established prolonged release dosage forms. Even if satisfactory adhesion to the skin is strictly linked to the efficacy and safety of the therapeutic treatment, nowadays numerous reports of in vivo ‘adhesion lacking’ are still addressed to regulatory agencies. The adhesive properties of a patch should be characterized considering i) the ability to form a bond with the surface of another material on brief contact and under light pressure (tack); ii) the resistance of the adhesive to flow (shear adhesion); and iii) the force required to peel away a patch from a surface (peel adhesion). Areas covered: In this manuscript, the most widely used methods to measure adhesive properties during development studies are described, along with the quality control of patches. The influence of formulative variables on patch adhesive properties, and their possible relationship with the in vivo adhesion performances, is also discussed. Expert o...

Adhesive properties: a critical issue in transdermal patch development.

Age- and disease-related factors can cause the skin to become susceptible to damage, particularly at dressing change. This review recommends ways of avoiding skin trauma when removing adhesive dressings and surgical tapes

Impact of adhesive surgical tape and wound dressings on the skin, with reference to skin stripping

Determining the mechanical properties of an individual’s skin is important in the fields of pathology, biomedical device design, and plastic surgery. To address this need, we present a finite element model that simulates the skin of the anterior forearm and posterior upper arm under a rich set of three-dimensional deformations. We investigated the suitability of the Ogden and Tong and Fung strain energy functions along with a quasi-linear viscoelastic law. Using non-linear optimization techniques, we found material parameters and in vivo pre-stresses for different volunteers. The model simulated the experiments with errors-of-fit ranging from 13.7 to 21.5%. Pre-stresses ranging from 28 to 92 kPa were estimated. We show that using only in-plane experimental data in the parameter optimization results in a poor prediction of the out-of-plane response. The identifiability of the model parameters, which are evaluated using different determinability criteria, improves by increasing the number of deformation orientations in the experiments.

Modeling the Mechanical Response of In Vivo Human Skin Under a Rich Set of Deformations

Measurement of the force-displacement response of in vivo human skin under a rich set of deformations

Various systems, methods and materials are disclosed that enable efficient delivery of an agent into an adhesively adhered article, in which the agent elicits a desired outcome, on demand. This strategy, though general in scope, is also more specifically described with regard to enabling painless or atraumatic removal of products adhering to mammalian tissues such as skin and hair by suitably exploiting the ingress of an appropriate agent or like fluid. Other techniques and articles that aid in the handling or removal of such adhesive products are also disclosed.

Systems, methods and materials for delivery and debonding on demand

Background/purpose Peeling of adhesive tape from hu-man skin can cause pain and trauma. The effects of the peel angle, peel rate, dwell time, subject, and order of testing were examined. Methods Adhesive tape was peeled from the volar forearms of four human subjects. The tape was 25.4-mm-wide Durapore by 3M. The rates ranged from 100 to 10,000 mm/min, the peel angle from 90 degrees to 180 degrees, and the dwell time from one to 15 min. The tensile testing machines'recorded the peel force and the displacement of the end of the tape. Results A range of maximum and average peel force values was observed. The peel force tended to be minimum for a peel angle around 150 degrees in most cases. As the peel rate was increased, the peel force generally tended to increases lightly, but the relationship was erratic. As the dwell time increased, the peel force increased and then settled down. Of the subjects tested, the skin of the oldest subject experienced the most displacement and highest peel forces(the maximum force over all tests was 3.6 N). The peel force tended to increase with repeated peeling from the same skin site. Compared with peeling from a rigid substrate such as steel, the peel force from skin was lower. Conclusion The results improve understanding of the factors affecting the peel force, which has been correlated previously with trauma caused by peeling adhesive tape from skin.

Experiments on peeling adhesive tapes from human forearms

Introduction Blood pressure (BP) monitoring is an essential component of sepsis management. The Surviving Sepsis Guidelines recommend invasive arterial BP (IABP) monitoring, although the benefits over non-invasive BP (NIBP) monitoring are unclear. This study investigated discrepancies between IABP and NIBP measurement and their clinical significance. We hypothesized that IABP monitoring would be associated with changes in management among patients with sepsis requiring vasopressors. Methods We performed a retrospective study of adult patients admitted to the critical care resuscitation unit at a quaternary medical center between January 1–December 31, 2017. We included patients with sepsis conditions AND IABP monitoring. We defined a clinically significant BP discrepancy (BPD) between NIBP and IABP measurement as a difference of > 10 millimeters of mercury (mm Hg) AND change of BP management to maintain mean arterial pressure ≥ 65 mm Hg. Results We analyzed 127 patients. Among 57 (45%) requiring vasopressors, 9 (16%) patients had a clinically significant BPD vs 2 patients (3% odds ratio [OR] 6.4; 95% CI: 1.2–30; P = 0.01) without vasopressors. In multivariable logistic regression, higher Sequential Organ Failure Assessment (SOFA) score (OR 1.33; 95% CI: 1.02–1.73; P = 0.03) and serum lactate (OR 1.27; 95% CI: 1.003–1.60, P = 0.04) were associated with increased likelihood of clinically significant BPD. There were no complications (95% CI: 0–0.02) from arterial catheter insertions. Conclusion Among our population of septic patients, the use of vasopressors was associated with increased odds of a clinically significant blood pressure discrepancy between IABP and NIBP measurement. Additionally, higher SOFA score and serum lactate were associated with higher likelihood of clinically significant blood pressure discrepancy. Further studies are needed to confirm our observations and investigate the benefits vs the risk of harm of IABP monitoring in patients with sepsis.

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Discrepancy Between Invasive and Noninvasive Blood Pressure Measurements in Patients with Sepsis by Vasopressor Status

http://www.jvascsurg.org/article/S0741521423009370/pdf

Surgical Treatment of Symptomatic Left Renal Vein Compression Results in Significant Improvement in Postoperative Quality of Life

Objective We aim to compare the effects of pre-existing mood disorders and chronic kidney disease (CKD) on ambulation outcomes for patients who have undergone major lower extremity amputation (MLEA) while also stratifying by the presence of social factors. Methods We performed a retrospective chart review of 700 patients admitted from 2014 to 2022 who underwent MLEA. We performed Chi-square tests and binomial logistic regression with p < 0.05 as our significance level. Results Mood disorder patients have higher rates of independent ambulation if they have familial support (p = 0.022), a listed primary care provider (PCP; p = 0.013), a six-month follow-up (p < 0.001), or a one-year follow-up (p < 0.001). Patients with a history of mood disorder have significantly decreased odds of prosthesis usage (OR: 0.58, 95% CI: 0.40-0.86) but have higher rates of prosthesis usage if they have familial support (p = 0.002), a PCP listed (p = 0.005), a six-month follow-up (p < 0.001), or a one-year follow-up (p < 0.001). CKD patients have significantly decreased odds of eventual independent ambulation (OR: 0.69, 95% CI: 0.49-0.97) but have significantly increased rates of independent ambulation if they have familial support (p =0.041) and six-month (p < 0.001) or one-year follow-up (p < 0.001). CKD patients only have significant changes in prosthesis usage with a six-month (p < 0.001) or one-year follow-up (p < 0.001). Conclusions Pre-existing CKD and mood disorders are associated with decreased odds of independent ambulation and prosthesis usage, respectively. Social factors such as family support, a listed PCP, and timely follow-up are associated with markedly improved ambulatory outcomes for MLEA patients with mood disorders and CKD, with significantly improved prosthesis usage outcomes in only the mood disorder population.

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A. C. Karwoski

Papers

Experiments on peeling adhesive tapes from human forearms

Discrepancy Between Invasive and Noninvasive Blood Pressure Measurements in Patients with Sepsis by Vasopressor Status

Surgical Treatment of Symptomatic Left Renal Vein Compression Results in Significant Improvement in Postoperative Quality of Life

Comparison of Pre-existing Mood Disorders and Chronic Kidney Disease as Predictors of Ambulatory Status After Major Limb Amputation