Acne Vulgaris in Skin of Color: A Systematic Review of the Effectiveness and Tolerability of Current Treatments.

Acne vulgaris is a common dermatosis frequently encountered in general dermatology and presents significant health-related quality of life and psychological challenges. Clinical studies on acne vulgaris in skin of color are limited; thus, it is likely that treatment recommendations to patients with darker skin types are drawn from trial data based on Caucasian skin. The aim of this study was to systematically review the effectiveness and tolerability of treatments used to treat acne vulgaris in patients with skin of color. A literature search was performed in the PubMed, Embase, and Scopus bibliographic databases, with a total of 1,477 retrieved articles, of which 1,316 were excluded after initial screening. Of the 93 studies assessed, 55 studies met our inclusion criteria (28 randomized controlled trials, 4 cohort studies, 6 post-hoc analyses, and 12 other interventional trials). The studies reported a total of 21,202 patients. Most studies explored topical therapies (23 studies) and photodynamic therapy (13 studies). Other treatments included laser/light therapy, systemic therapy, chemical peels, and radiofrequency and microneedling. In general, the different treatment modalities offered an improvement in lesion count and were well tolerated, with no report of major adverse events. However, due to limited evidence, we were unable to draw firm conclusions from the results of this review to guide decisions in practice, particularly with respect to long-term outcomes, in patients with skin of color and acne vulgaris.

The clinical and translational prospects of microneedle devices, with a focus on insulin therapy for diabetes mellitus as a case study.

Microneedles have the clinical advantage of being able to deliver complex drugs across the skin in a convenient and comfortable manner yet haven't successfully transitioned to medical practice. Diabetes mellitus is a complicated disease, which is commonly treated with multiple daily insulin injections, contributing to poor treatment adherence. Firstly, this review determines the clinical prospect of microneedles, alongside considerations that ought to be addressed before microneedle technology can be translated from bench to bedside. Thereafter, we use diabetes as a case study to consider how microneedle-based-technology may be successfully harnessed. Here, publications referring to insulin microneedles were evaluated to understand whether insertion efficiency, angle of insertion, successful dose delivery, dose adjustability, material biocompatibility and therapeutic stability are being addressed in early stage research. Moreover, over 3,000 patents from 1970 to 2019 were reviewed with the search term '"microneedle" AND "insulin"' to understand the current status of the field. In conclusion, the reporting of early stage microneedle research demonstrated a lack of consistency relating to the translational factors addressed. Additionally, a more rational design, based on a patient-centred approach is required before microneedle-based delivery systems can be used to revolutionise the lives of people living with diabetes following regulatory approval.

Improving recognition among undergraduate and postgraduate trainees of dermatological conditions in skin of colour: a cross-sectional quality improvement project.

It is well-recognized that skin of colour (SOC) is under-represented in undergraduate and postgraduate curricula in the UK. The primary objective of this Quality Improvement Project (QIP) was to improve the confidence of medical students and junior doctors in recognizing dermatological conditions in SOC. We developed two educational interventions to introduce participants to the clinical presentation of dermatological conditions in SOC. A five-point Likert scale measured participants' confidence, and an eight-question assessment quantified differences in knowledge. Results showed that 39% of students and 67% of junior doctors had not received SOC teaching during their undergraduate training. Following the lecture, mean Likert scores for confidence in recognizing conditions in SOC increased in the medical student and junior doctor cohorts by 2.5 and 1.82, respectively (P < 0.001 for both). The mean assessment scores increased by 3.68 and 3.87, respectively (P < 0.001 for both). These results confirm the under-representation of SOC in medical education and highlight the need to diversify the Dermatology undergraduate and postgraduate curricula.

Microneedles for drug delivery: trends and progress.

In recent years, there has been a surge in the research and development of microneedles (MNs), a transdermal delivery system that combines the technology of transdermal patches and hypodermic needles. The needles are in the hundreds of micron length range and therefore allow relatively little or no pain. For example, biodegradable MNs have been researched in the literature and have several advantages compared with solid or hollow MNs, as they produce non-sharp waste and can be designed to allow rapid or slow release of drugs. However, they also pose a disadvantage as successful insertion into the stratum corneum layer of the skin relies on sufficient mechanical strength of the biodegradable material. This review looks at the various technologies developed in MN research and shows the rapidly growing numbers of research papers and patent publications since the first invention of MNs (using time series statistical analysis). This provides the research and industry communities a valuable synopsis of the trends and progress being made in this field.

Delivery of large molecular protein using flat and short microneedles prepared using focused ion beam (FIB) as a skin ablation tool.

Many studies have been reported in the literature on the effects of various geometries and lengths of microneedles (MNs) on transdermal drug delivery using a variety of drug molecules. In particular, sharp-tipped MNs have been used to disrupt the top layer of the skin, namely, stratum corneum (SC). It has also been shown that short- and flat-tipped MNs can pierce the SC and they have the potential to increase drug permeability. However, there is little work that explores MNs as a skin ablative tool with a view to increasing skin permeability. To address this point, well-defined small patterns (size of individual pattern 10-20 µm) on the tip of flat MN (tip radius of individual MN ∼250 µm) were created and their effects evaluated on the permeability of bovine serum albumin (BSA), which is chosen as a model drug of high molecular weight. The patterns on the tip of flat MN act as rough surfaces (e.g. like sand paper) which when applied on the surface of the skin ablate the SC layer. Focused ion beam (FIB) has been used as the fabrication technique for the MNs. The permeability data are then compared with the other data for flat- and sharp-tipped MN. The permeability data from passive diffusion experiments are used as the reference case. The exact number of MNs or patterns in the flat and patterned MN patches is not considered as important as they have not been designed to pierce the skin. However, this is an important consideration in the case of sharp MNs as they pierce and create cavities in the skin. It is found that the delivery of BSA with the fabricated flat and patterned MNs gave similar but somewhat lower drug permeation profile in comparison to the sharp MNs. Passive diffusion showed no permeation, as would be expected due to the large size of the chosen molecule.

Effect of force of microneedle insertion on the permeability of insulin in skin.

Many experiments conducted in the literature have investigated the effect of microneedles (MNs) on insulin permeation across skin. There are also a number of articles that deal with the effect of MN insertion force in skin. However, there is little known on quantifying the relationship between the effect of MN insertion force and the amount of insulin permeated for given MNs. This issue is addressed in this article. MNs of 1100 µm and 1400 µm are used to conduct in vitro permeability experiments on porcine skin, using insulin. Histological images of MN treated skin are obtained from a microtome and the viscoelastic properties of the skin sample are measured using a rheometer. An in-house insertion force device is utilized that can reproducibly apply a specified force on MNs for a set period of time using compressed air. It is deduced that when porcine skin was pretreated with an applied force of 60.5 N and 69.1 N, the resultant amount of insulin permeated was approximately 3 µg and 25 µg over a 4-hour period for the MNs used. The amount of MN force applied to porcine skin was shown to be related to the amount of insulin permeated. An increase in insertion force increase the amount of insulin permeated. It was also demonstrated that using insufficient force may have reduced or prevented the amount of insulin passing through the skin, regardless of the geometry of the MNs.