The use of cyclosporine in dermatology: part II

Topical delivery of Cyclosporine A into the skin using SPACE-peptide

Cyclosporine A (CsA) is used for the treatment of psoriasis; however systemic administration of CsA is potentially life threatening and there are long-term side effects. Topical application of CsA has the potential to overcome this hurdle; however, its use is limited by poor water solubility and low permeability. Here, we report the use of a physical mixture of SPACE-peptide and CsA in an aqueous ethanol solution to enhance the dermal absorption of the drug. The aqueous ethanol solution (hydroethanolic solution) containing 5mg/mL CsA and 50mg/mL of free SPACE-peptide (SP50) delivered about 30% of topically applied CsA into the porcine skin in vitro and led to an approximately 9-fold (p<0.01) increase in accumulation in viable epidermis compared to the hydroethanolic solution without SPACE-peptide (control group). In vivo biodistribution and pharmacokinetic studies performed using SKH1 hairless mice also confirmed the efficacy of SP50 in dermal delivery of CsA and also demonstrated its advantages over other routes in terms of minimizing its systemic absorption. Topical application of SP50 significantly increased the localization of CsA in the target skin (113.1±13.6(μg/g)/mg) compared to all other groups (p<0.01). In addition, SP50 led to significantly higher skin/blood ratio (443.4±181.5) and skin/liver ratio (1059.5±110.8) of CsA compared to all other groups (p<0.01). The SP50 formulation reported here offers a promising approach for the dermal delivery of CsA.

Targeted cutaneous delivery of ciclosporin A using micellar nanocarriers and the possible role of inter-cluster regions as molecular transport pathways

Oral administration of ciclosporin A (CsA) is indicated in the treatment of severe recalcitrant plaque psoriasis. However, CsA is both nephro- and hepatotoxic and its systemic administration also exposes the patient to other severe side effects. Although topical delivery of CsA, targeted directly to psoriatic skin, would offer significant advantages, there are no topical formulations approved for dermatological use. The aim of this work was to formulate CsA loaded polymeric micelles using the biodegradable and biocompatible MPEG-dihexPLA diblock copolymer and to evaluate their potential for delivering the drug selectively into the skin without concomitant transdermal permeation. Micelle formulations were characterised with respect to drug content, size and morphology. Micelle and drug penetration pathways were subsequently visualised with confocal laser scanning microscopy (CLSM) using fluorescein labelled CsA (Fluo-CsA) and Nile-Red (NR) labelled copolymer. Visualisation studies typically use fluorescent dyes as "model drugs"; however, these may have different physicochemical properties to the drug molecule under investigation. Therefore, in this study it was decided to chemically modify CsA and to use this structurally similar fluorescent analogue to visualise molecular distribution and transport pathways. Molecular modelling techniques and experimental determination of log D served as molecular scale and macroscopic methods to compare the lipophilicity of CsA and Fluo-CsA. The spherical, homogeneous and nanometre-scale micelles (with Zav from 25 to 52 nm) increased the aqueous solubility of CsA by 518-fold. Supra-therapeutic amounts of CsA were delivered to human skin (1.4±0.6 μg/cm2, cf. a statistically equivalent 1.1±0.5 μg/cm2 for porcine skin) after application of the formulation with the lowest CsA and copolymer content (1.67±0.03 mg/ml of CsA and 5mg/ml of copolymer) for only 1h without concomitant transdermal permeation. Fluo-CsA was successfully synthesised, characterised and incorporated into fluorescent NR-MPEG-dihexPLA micelles; its conformation was not modified by the addition of fluorescein and its log D, measured from pH4 to 8, was equivalent to that of CsA. Fluo-CsA and NR-MPEG-dihexPLA copolymer were subsequently visualised in skin by CLSM. The images indicated that micelles were preferentially deposited between corneocytes and in the inter-cluster regions (i.e. between the clusters of corneocytes). Fluo-CsA skin penetration was deeper in these structures, suggesting that inter-cluster penetration is probably the preferred transport pathway responsible for the increased cutaneous delivery of CsA.

LD-aminopterin in the canine homologue of human atopic dermatitis: a randomized, controlled trial reveals dosing factors affecting optimal therapy

Background

Options are limited for patients with atopic dermatitis (AD) who do not respond to topical treatments. Antifolate therapy with systemic methotrexate improves the disease, but is associated with adverse effects. The investigational antifolate LD-aminopterin may offer improved safety. It is not known how antifolate dose and dosing frequency affect efficacy in AD, but a primary mechanism is thought to involve the antifolate-mediated accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). However, recent in vitro studies indicate that AICAR increases then decreases as a function of antifolate concentration. To address this issue and understand how dosing affects antifolate efficacy in AD, we examined the efficacy and safety of different oral doses and schedules of LD-aminopterin in the canine model of AD.

Methods and Findings

This was a multi-center, double-blind trial involving 75 subjects with canine AD randomized to receive up to 12 weeks of placebo, once-weekly (0.007, 0.014, 0.021 mg/kg) or twice-weekly (0.007 mg/kg) LD-aminopterin. The primary efficacy outcome was the Global Score (GS), a composite of validated measures of disease severity and itch. GS improved in all once-weekly cohorts, with 0.014 mg/kg being optimal and significant (43%, P<0.01). The majority of improvement was seen by 8 weeks. In contrast, GS in the twice-weekly cohort was similar to placebo and worse than all once-weekly cohorts. Adverse events were similar across all treated cohorts and placebo.

Conclusions

Once-weekly LD-aminopterin was safe and efficacious in canine AD. Twice-weekly dosing negated efficacy despite having the same daily and weekly dose as effective once-weekly regimens. Optimal dosing in this homologue of human AD correlated with the concentration-selective accumulation of AICAR in vitro, consistent with AICAR mediating LD-aminopterin efficacy in AD.

Treatment of atopic dermatitis in pregnancy

Atopic dermatitis (AD), also referred to as eczema, is one of the most frequently observed skin diseases in pregnant patients. The presentation and histopathology of this condition during pregnancy is identical to that of the non-pregnant individual. AD is a T-helper 2 dominant disease and may worsen during pregnancy, which favors this population of T-lymphocytes. AD management during pregnancy requires special precautions to avoid harming the fetus. Herein is an exploration of the different options available for the treatment of the pregnant patient with AD. The management of concomitant bacterial and viral infections is also discussed.

Cyclosporine regimens in plaque psoriasis: an overview with special emphasis on dose, duration, and old and new treatment approaches

Cyclosporine A (CsA) is one of the most effective systemic drugs available for the treatment of psoriasis, as evidenced by the results of several randomized studies and by a prolonged experience in dermatological setting. In clinical practice, CsA is usually used for the induction of psoriasis remission at a daily dose included in the range of 2.5–5 mg/kg and with intermittent short-term regimens, lasting on average 3–6 months. The magnitude and rapidity of response are dose dependent, as well as the risk of development of adverse events. Therefore, the dose should be tailored to patient's needs and general characteristics and adjusted during the treatment course according to both the efficacy and tolerability. Some studies support the feasibility of pulse administration of CsA for a few days per week for both the induction and the maintenance of response in psoriasis patients. This paper will review the data on CsA regimens for plaque-type psoriasis and will focus the attention on dose, treatment duration, novel schedules, and role in combination therapies, including the association with biologicals.

Fine tuning the inhibition profile of cyclosporine A by derivatization of the MeBmt residue

Unique respect: The biological properties of four CsA derivatives were fine-tuned by tractable modifications of the MeBmt residue. The new CsA derivatives share strong inhibitory activity toward cyclophilins (Cyps), but each is unique with respect to immunosuppressive action and cellular localization. These CsA analogues can be used to study the physiological roles of extracellular Cyps.

The effects of alcohol on the metabolism and toxicology of anti-psoriasis drugs

INTRODUCTION

Alcohol has long been suspected to be a triggering and precipitating factor of psoriasis. Alcohol misuse is common in patients with moderate-to-severe psoriasis and appears to impair treatment outcome.

AREAS COVERED

In this article, the authors review the available data regarding the metabolic and toxicological interactions between anti-psoriasis systemic drugs and ethanol and/or alcoholic beverages. Special attention is given to the influence of alcohol consumption on the hepatotoxic risk of some anti-psoriasis drugs. The article was prepared using a MEDLINE literature search.

EXPERT OPINION

The available knowledge highlights the existence of a few significant pharmacological interactions, such as the reduced exposure to cyclosporine by red wine, the possible increase of cyclosporine levels following a heavy acute alcohol intake, and, especially, the conversion of acitretin to etretinate, in the presence of ethanol, with important implications in females of child-bearing potential. There are limited data on the contributing role of alcohol in the hepatotoxicity induced by some anti-psoriasis drugs and the existing information on this topic is still controversial. However, further investigation is needed to assess the relevance of interactions between alcohol consumption and drug therapy for psoriasis, under both pharmacological and toxicological perspectives. Long-term prospective studies on large cohorts of patients are warranted to disclose the actual significance of such potential interactions in clinical practice.

Lesional dendritic cells in patients with chronic atopic dermatitis and psoriasis exhibit parallel ability to activate T-cell subsets

BACKGROUND

Atopic dermatitis (AD) and psoriasis represent polar immune diseases. AD is a T(H)2/T(H)22-dominant disease, whereas psoriasis is considered a T(H)1/T(H)17 disease. Local immune deviation is suggested to be regulated by dendritic cell (DC)-induced T-cell polarization and recruitment of specific T-cell subsets by chemokines. Although the role of chemokines is well documented, the actual contribution of DCs to activate polar T-cell subsets in human subjects is still a matter of speculation.

OBJECTIVE

We sought to elucidate the significance of each cutaneous DC subset in disease-specific T-cell immune deviation.

METHODS

We performed a comprehensive analysis of major cutaneous resident (Langerhans cells and blood dendritic cell antigen 1-positive dermal DCs) and inflammatory (inflammatory dendritic epidermal cells and blood dendritic cell antigen 1-negative dermal DCs) DC subsets directly isolated from the lesional skin of patients with AD and those with psoriasis.

RESULTS

The ability of each DC subset to expand T(H)1, T(H)2, T(H)17, and T(H)22 subsets was similar between the 2 diseases, despite the association of both with accumulation of resident and inflammatory DCs. We also confirmed differential upregulation of chemokine expression in patients with AD (CCL17, CCL18, and CCL22) and psoriasis (CXCL1, IL-8, and CCL20). The expression of CCL17 and CCL22 was higher in Langerhans cells from patients with AD than from patients with psoriasis, whereas the opposite was observed for CXCL9 and CXCL10.

CONCLUSION

Our results suggest that DC polarity does not directly drive differential T-cell subset responses. Alternatively, disease-specific chemokines might recruit specific memory T-cell subsets into the skin, which in turn might be activated and expanded by DCs at the site of inflammation, maintaining differential immune polarity in these diseases.

Guidelines of care for the management of psoriasis and psoriatic arthritis: section 6. Guidelines of care for the treatment of psoriasis and psoriatic arthritis: case-based presentations and evidence-based conclusions

Psoriasis is a common, chronic, inflammatory, multisystem disease with predominantly skin and joint manifestations affecting approximately 2% of the population. In the first 5 parts of the American Academy of Dermatology Psoriasis Guidelines of Care, we have presented evidence supporting the use of topical treatments, phototherapy, traditional systemic agents, and biological therapies for patients with psoriasis and psoriatic arthritis. In this sixth and final section of the Psoriasis Guidelines of Care, we will present cases to illustrate how to practically use these guidelines in specific clinical scenarios. We will describe the approach to treating patients with psoriasis across the entire spectrum of this fascinating disease from mild to moderate to severe, with and without psoriatic arthritis, based on the 5 prior published guidelines. Although specific therapeutic recommendations are given for each of the cases presented, it is important that treatment be tailored to meet individual patients' needs. In addition, we will update the prior 5 guidelines and address gaps in research and care that currently exist, while making suggestions for further studies that could be performed to help address these limitations in our knowledge base.