A novel foam vehicle for delivery of topical corticosteroids

First In Vivo Applicational Data of Foam-Based Intrathoracic Chemotherapy (FBiTC) in a Swine Model

BACKGROUND

For decades, both intraperitoneal and pleural chemotherapy (IPC) have been delivered as a liquid solution. Recent studies suggest that foam carriers outperform liquid carriers for locoregional chemotherapy. For the first time, this study aims to evaluate the feasibility, safety, and characteristics of foam-based intrathoracic chemotherapy (FBiTC) in an in vivo setting.

METHODS

In this study, contrast-enhanced FBiTC with doxorubicin was delivered via video-assisted thoracoscopy (VAT) in three swine under general anesthesia. Intraoperative and postoperative parameters, blood analyses, vital signs, and anesthesiologic data were collected. Additionally, an intraoperative computer tomography (CT) scan was performed, and histological tissue sections were collected and further analyzed using fluorescence microscopy.

RESULTS

FBiTC was delivered without major complications. End-tidal capnometry detected increased CO2 levels with reduced peripheral oxygen saturation and increased blood pressure and heart rate. No major intra- or postoperative complications were observed. CT scans confirmed a multidirectional distribution pattern of foam. Postoperative laboratory workup did not reveal any critical changes in hemoglobin, white blood count, or platelets. There was no evidence of critical kidney impairment or liver function. Fluorescence microscopy of tissue specimen detected doxorubicin in pleural tissues.

DISCUSSION

Our preliminary results are encouraging and indicate that FBiTC is feasible. However, to consider a possible clinical application, further studies are required to investigate the pharmacologic, pharmacodynamic, and physical properties of FBiTC and to ensure the safety of the overall procedure regarding oxygenation levels and capnography parameters.

Topical foam as a promising carrier system for active pharmaceutical ingredients: review of clinical studies

Skin disorders are preferentially treated by topical administration of medicines or cosmetics because of the possibility of local action. However, a great concern is the delivery of topical actives with effective penetration through the stratum corneum to ensure the desired effect. Considering the search for a carrier system that allows the penetration/permeation of active pharmaceutical ingredients through this structure, searching for effective topical pharmaceutical forms is needed. Foams have been widely studied over the years due to their high capacity to favor the active to overcome the cutaneous barrier and because this form of presentation has ease of application and high acceptability by users. The objective of this review was to analyze the potential of foam as a topical pharmaceutical form for treating skin disorders, upon clinical cases reported in the literature. Foam presents technical advantages when compared to other conventional topical pharmaceutical forms due to its fast action, high tolerance, and safety, with reduction or total remission of adverse events. Regarding the patient, foam increased the rate of adherence to the treatment. Therefore, it is concluded that foam is an effective, secure, and stable topical presentation form for carrying active pharmaceutical ingredients and widely accepted by patients.

Vehicles for Drug Delivery and Cosmetic Moisturizers: Review and Comparison

Many dermatological conditions, such as eczema and psoriasis, are treated with topical therapeutic products. Instead of applying the active drug directly onto the skin, it is combined with a vehicle to aid in its delivery across the stratum corneum (SC) and into deeper regions of the skin, namely the epidermis and dermis. Absorption into the systemic circulation is minimized. Topical vehicles are also used as cosmetic moisturizers (often termed emollient therapy) to ameliorate dry skin, which is a cornerstone of the management of various dermatological conditions, including xerosis, eczema, psoriasis, and aging. The most common topical vehicles include ointments, creams, gels, and lotions, among others. It is crucial that topical vehicles are chosen based upon the size and properties (wet/dry, mucous/non-mucous, healthy/diseased) of the skin to be treated in order to optimize application and contact of the product with the skin, as this can have profound impacts on potency, efficacy, and patient compliance. This review examines common topical vehicles used for drug delivery and cosmetic moisturizers, including their formulation, advantages and disadvantages, and effects on the skin. The unique rules imposed by governing regulatory bodies in Australia and around the world, in terms of topical product claims, are also briefly examined.

Medicated Foams and Film Forming Dosage Forms as Tools to Improve the Thermodynamic Activity of Drugs to be Administered Through the Skin

Medicated foams and film forming systems are dosage forms formulated to undergo a con-trolled metamorphosis when applied on the skin. Indeed, due to the presence of propellant or a particular air-spray foam pump, a liquid can generate foam when applied on the stratum corneum, or a liquid or conventional dosage form can form on the skin a continuous film as a consequence of the solvent evapora-tion. Thanks to these controlled modifications, the drug thermodynamic activity increases favoring the skin penetration and, therefore, the bioavailability with respect to conventional semi-solid and liquid dosage forms. Furthermore, the available clinical data also evidence that these dosage forms improve the patient’s compliance. The main formulative aspects of medicated foams and film forming systems are reviewed with the aim to underline the possible advantages in terms of biopharmaceutical performances and pa-tient’s adherence.

A Guide to Topical Vehicle Formulations

Adherence to topical treatment for a variety of chronic skin conditions, such as psoriasis, acne, and atopic dermatitis, is known to be very poor. A number of factors contribute to this phenomenon, including lack of treatment efficacy and patient concerns regarding side effects, among others. At the forefront of barriers facing optimal patient adherence to topical treatment is choosing the ideal topical vehicle formulation. Medical professionals have demonstrated a lack of understanding with respect to the composition and nomenclature of the various topical formulations. In this review, we clarify the properties and definitions of the following topical formulations: ointments, creams, lotions, topical solutions, topical suspensions, gels, foams, and sprays. We also provide suggested areas of application for the aforementioned formulations and a succinct, patient-geared summary of their advantages and disadvantages. This review hopes to deliver a clear and concise practical summary of the most commonly encountered topical formulations for the treatment of cutaneous disease for medical professionals. This will allow clinicians to provide their patients with accurate information to facilitate informed choice of topical formulation, which may serve to improve treatment adherence.

Calcipotriene betamethasone dipropionate aerosol foam in the treatment of plaque psoriasis: a review of the literature

Psoriasis is a common chronic immune-mediated skin disease which has a significant impact on patients' quality of life, and is associated with numerous comorbidities (i.e., psoriatic arthritis, Crohn's disease and cardiovascular disease). A greater understanding of its immunopathogenesis has guided the development of novel, more targeted therapies. Nonetheless, traditional treatment with topical agents, phototherapy and systemic medications is used in the management of the majority of psoriasis patients. Mainstay topical treatments include corticosteroids and vitamin D derivatives. Calcipotriene/betamethasone dipropionate aerosol foam is a novel single product combination, which seeks to provide superior therapeutic efficacy in addition to enhanced cosmetic properties. This article reviews the literature on the pharmacology and clinical data in terms of safety, efficacy and patient satisfaction of this topical medication.

Efficacy of an innovative aerosol foam formulation of fixed combination calcipotriol plus betamethasone dipropionate in patients with psoriasis vulgaris

Background and Objective

The antipsoriatic effect of an innovative aerosol foam formulation of fixed combination calcipotriol 50 μg/g (as hydrate; Cal) and betamethasone 0.5 mg/g (as dipropionate; BD) was explored in order to compare the effect with that of the first-line treatment Cal/BD ointment.

Methods

This was a Phase IIa, single-centre, investigator-blinded, exploratory study, with intra-individual comparison using a modified psoriasis plaque test. Patients were treated once daily (6 days/week) for 4 weeks with Cal/BD foam, Cal/BD ointment, BD foam and Cal/BD foam vehicle, randomized to four plaque test sites (5 cm² each). The primary efficacy endpoint was change in total clinical score (TCS; sum of erythema, scaling and lesional thickness). Secondary endpoints included ultrasonographic changes in total skin thickness and echo-poor band thickness, and adverse events.

Results

Twenty-four patients, median age 52.5 years (range 21–75), completed this study. At week 4, test sites treated with Cal/BD foam had a significantly greater decrease in mean (±SD) TCS (−6.00 ± 1.27) versus those treated with Cal/BD ointment (−5.25 ± 1.78; difference −0.75; 95 % CI −1.46 to −0.04; p = 0.038), BD foam (−4.96 ± 1.85; difference −1.04; 95 % CI −1.75 to −0.33; p = 0.005) or foam vehicle (−1.88 ± 1.12; difference −4.13; 95 % CI −4.83 to −3.42; p < 0.001). Total skin thickness and echo-poor band thickness of Cal/BD foam-treated sites were reduced to a greater extent than those treated with comparators. Eleven patients reported 17 adverse events, the most frequent being headache (five patients). There were no lesional/perilesional adverse events or adverse drug-related events.

Conclusions

Cal/BD foam demonstrated a significant improvement in antipsoriatic effect over Cal/BD ointment, BD foam and foam vehicle alone.

The potential of polymeric film-forming systems as sustained delivery platforms for topical drugs

INTRODUCTION

Dosing regimens requiring multiple daily applications frequently result in poor patient compliance, especially in the treatment of chronic skin diseases. Consequently, development of sustained delivery systems for topical drugs permitting less frequent dosing is of continuing interest for dermatological therapy.

AREAS COVERED

This potential of polymeric film-forming systems (FFS), created in situ on the skin, as sustained delivery platforms for topical drug delivery is reviewed. Key formulation parameters that determine delivery efficiency are considered focussing on those that permit a drug reservoir to be established in the upper layers of the skin and/or on the skin surface from which release can be sustained over a prolonged period. The advantageous and superior cosmetic attributes of FFS (compared to conventional semi-solid formulations) that offer significantly improved patient compliance are also addressed.

EXPERT OPINION

The promise of polymeric FFS as convenient and aesthetic platforms for sustained topical drug delivery is clear. Manipulation of the formulation allows the delivery profile to be customized and optimized to take advantage of both a rapid, initial input of drug into the skin (likely due to a transient period of supersaturation) and a slower, controlled release over an extended time from the residual film created thereafter.

Current applications of foams formed from mixed surfactant-polymer solutions

Foams cannot be generated without the use of special foaming agents, as pure liquids do not foam. The most common foaming agents are surfactants, however often for foam stability one active agent is not enough, it is necessary to add other component to increase foam lifetime. Foams on everyday use are mostly made from mixture of different components. Properly chosen combinations of two active ingredients lead to a faster foam formation and increased foam stability. During the last decade polymers (mainly polyelectrolytes and proteins) have become frequently used additives to foaming solutions. Mixtures of surfactants and polymers often demonstrate different foaming properties in comparison to surfactant only or polymer only solutions. The nature of surfactant-polymer interactions is complicated and prediction of resulting foaming properties of such formulations is not straightforward. Properties and foaming of surfactant-polymer mixtures are discussed as well as current applications of foams and foaming agents as foams are widely used in cosmetics, pharmaceutics, medicine and the food industry.

A Novel Aerosol Foam Formulation of Calcipotriol and Betamethasone Has No Impact on HPA Axis and Calcium Homeostasis in Patients With Extensive Psoriasis Vulgaris

Background:

Fixed combination calcipotriol 50 µg/g (Cal; as hydrate) plus betamethasone 0.5 mg/g (as dipropionate; BD) has been formulated in an innovative aerosol foam.

Objective:

To assess systemic safety of Cal/BD aerosol foam.

Methods:

In a multicentre, single-arm, open-label, maximal-use systemic-exposure trial, adult patients with moderate to severe, extensive psoriasis (15%-30% of body surface area, including ≥30% of scalp) applied Cal/BD foam once daily. Endpoints were week 4 abnormal adrenocorticotropic hormone (ACTH) challenge test and change in albumin-corrected serum calcium, 24-hour urinary calcium excretion, and urinary calcium-creatinine ratio.

Results:

35 patients reaching week 4 exhibited normal ACTH responses. At week 4, changes in calcium homeostasis were minor and not clinically relevant; no patients experienced elevations above normal. Disease severity generally improved, and 49% of patients achieved treatment success according to the Physician’s Global Assessment of Disease Severity.

Conclusion:

No clinically relevant HPA axis or calcium homeostasis impact was observed with 4 weeks of once-daily Cal/BD foam in patients with extensive psoriasis vulgaris.

Responsive foams for nanoparticle delivery

We have developed responsive foam systems for nanoparticle delivery. The foams are easy to make, stable at room temperature, and can be engineered to break in response to temperature or moisture. Temperature-responsive foams are based on the phase transition of long chain alcohols and could be produced using medical grade nitrous oxide as a propellant. These temperature-sensitive foams could be used for polyacrylic acid (PAA)-based nanoparticle delivery. We also discuss moisture-responsive foams made with soap pump dispensers. Polyethylene glycol (PEG)-based nanoparticles or PMMA latex nanoparticles were loaded into Tween 20 foams and the particle size was not affected by the foam formulation or foam break. Using biocompatible detergents, we anticipate this will be a versatile and simple approach to producing foams for nanoparticle delivery with many potential pharmaceutical and personal care applications.

Foam drainage placed on a porous substrate

A model for drainage/imbibition of a foam placed on the top of a porous substrate is presented. The equation of liquid imbibition into the porous substrate is coupled with a foam drainage equation at the foam/porous substrate interface. The deduced dimensionless equations are solved using a finite element method. It was found that the kinetics of foam drainage/imbibition depends on three dimensionless numbers and the initial liquid volume fraction. The result shows that there are three different regimes of the process. Each regime starts after initial rapid decrease of a liquid volume fraction at the foam/porous substrate interface: (i) rapid imbibition: the liquid volume fraction inside the foam at the foam/porous substrate interface remains constant close to a final liquid volume fraction; (ii) intermediate imbibition: the liquid volume fraction at the interface with the porous substrate experiences a peak point and imbibition into the porous substrate is slower as compared with the drainage; (iii) slow imbibition: the liquid volume fraction at the foam/porous substrate interface increases to a maximum limiting value and a free liquid layer is formed between the foam and the porous substrate. However, the free liquid layer disappears after some time. The transition points between these three different drainage/imbibition regimes were delineated by introducing two dimensionless numbers.

Comparison of reservoir effect of topical corticosteroids in an experimental animal model by histamine-induced wheal suppression test

Introduction:

Topical corticosteroids used in various dermatological diseases are available in different potencies and different formulations. The reservoir effect of different potency corticosteroids in the stratum corneum will help the clinicians to choose an appropriate topical steroid to maximize their efficacy and safety as therapeutic agents.

Aims:

This study was designed to compare the duration of reservoir of different potency topical corticosteroids experimentally in rabbits using histamine-induced wheal suppression test.

Materials and Methods:

The study was carried out in albino rabbits (as their skin is similar to humans) using four different concentrations of topical steroids, namely mometasone furoate ointment (0.1%), fluticasone propionate ointment (0.005%), betamethasone valerate cream (0.1%), and hydrocortisone butyrate cream (0.1%). These were applied on the back of rabbit on one side and the vehicle was applied on the other. One hour later, histamine-induced wheal suppression test was performed on both sides and wheal area was measured at 10 min for 7 days. Statistical analysis was done by ANOVA followed by post hoc test.

Results:

Maximum wheal suppression was seen on day 1 (P<0.001) in all four groups, both at test and at control sites. Interday comparison of mean wheal size by topical steroids showed that the reservoir of mometasone furoate ointment (0.1%) persisted till day 4 in the stratum corneum of the skin. In case of fluticasone propionate ointment (0.005%) and betamethasone valerate cream (0.1%), the reservoir persisted till day 2 and for hydrocortisone butyrate cream (0.1%), the reservoir was present only on day 1.

Conclusions:

It is concluded that the duration of reservoir depends on the potency of topical steroids. Higher the potency more is the duration of reservoir in stratum corneum and vice versa.

Investigation of solute permeation across hydrogels composed of poly(methyl vinyl ether-co-maleic acid) and poly(ethylene glycol)

OBJECTIVES

Swelling kinetics and solute permeation (theophylline, vitamin B(12) and fluorescein sodium) of hydrogels composed of poly(methyl vinyl ether-co-maleic acid) (PMVE/MA) and poly(ethylene glycol) (PEG) are presented.

METHODS

The effects of PMVE/MA and PEG 10 000 content on swelling behaviour (percentage swelling, the type of diffusion and swelling rate constant) were investigated in 0.1 m phosphate buffer. Network parameters, such as average molecular weight between crosslinks (M(c)) and crosslink density, were evaluated.

KEY FINDINGS

The percentage swelling and M(c) of hydrogels increased with decrease in PMVE/MA content, where the water diffusion mechanism into the hydrogels was Class-II type. In contrast, increase in PMVE/MA content caused an increase in the crosslink density. Permeation of theophylline, vitamin B(12) and fluorescein sodium, with increasing hydrodynamic radii, was studied through the equilibrium swollen hydrogels composed of PMVE/MA and PEG. In general, the permeability and diffusion coefficients of all three solutes decreased with increase in the PMVE/MA content. In addition, permeability and diffusion coefficient values increased with decreases in the hydrodynamic radii of the solute molecules.

CONCLUSIONS

The hydrogels have shown a change in swelling behaviour, crosslink density, M(c) and solute permeation with change in PMVE/MA content, thus suggesting a potential application in controlled drug-delivery systems.

Topical delivery for the treatment of psoriasis

IMPORTANCE OF THE FIELD

Psoriasis is one of the most common human skin diseases. Topical therapy forms the cornerstone in the management of mild-to-moderate psoriasis. Topical therapies are also used as adjunctive to systemic therapy in moderate and severe forms of the disease.

AREAS COVERED IN THIS REVIEW

In this review, an overview of psoriasis pathogenesis, new topical medications for psoriasis, new targets and molecules, combination topical therapies and combination of topical and phototherapy is provided. Over the past decade several efficacious and acceptable treatment options have emerged from the age-old therapies. The development of sophisticated formulation options has led to an enhancement in the rate and extent of drug delivery across the skin, increasing therapeutic value and improving patient compliance.

WHAT THE READER WILL GAIN

Readers will learn about monotherapy and combination topical products as well as new topical drug delivery technology to achieve optimal clinical outcomes. This review will highlight the need to generate more dermal pharmacokinetic data for better understanding of the impact of formulation change on skin pharmacokinetics to help design improved topical drug delivery systems.

TAKE HOME MESSAGE

New topical formulations have the potential to achieve better efficacy with improved safety profile.

Topical clobetasol propionate in the treatment of psoriasis: a review of newer formulations

Ultrapotent topical corticosteroids are the mainstay of psoriasis treatment, used either alone or in combination with a topical vitamin D analog. Traditionally used in an ointment vehicle for psoriasis, clobetasol propionate 0.05% is also available in spray, foam, lotion, and shampoo formulations, which may provide for improved convenience and acceptance in many patients with similar efficacy, safety, and tolerability as the traditional ointment and cream formulations. To compare newer formulations with traditional ointment and cream formulations, we performed a systematic review of the literature. Search terms included 'clobetasol propionate,' in combination with 'psoriasis,' 'vasoconstriction,' 'vasoconstrictor,' or 'absorption' for each of the four vehicles ('spray,' 'foam,' 'lotion,' and 'shampoo'). While there are very few direct comparison studies between clobetasol propionate in different vehicles, the efficacy rates (with success defined as clear or almost clear of psoriasis) for more recent formulations are high, with most patients achieving success after 2-4 weeks of treatment in well controlled clinical trials, with response rates that are similar to those with the traditional clobetasol propionate ointment. Small differences in vasoconstrictor potency or cutaneous absorption have been noted among the formulations, but the clinical significance of these observations is difficult to discern. Recent research has emphasized the importance of treatment adherence in the management of psoriasis. Adherence to treatment is likely to be a far more important determinant of success than are small differences in drug delivery, especially in actual clinical use as opposed to the well controlled environment of clinical trials. For patients who prefer a less messy vehicle, adherence and outcomes are likely to be better with the more recent formulations compared with the traditionally recommended ointment.

Clobetasol propionate emollient formulation foam in the treatment of corticosteroid-responsive dermatoses

BACKGROUND

Topical corticosteroids are the most common treatment modality for patients with psoriasis and atopic dermatitis; however, the efficacy of topical corticosteroids is often hampered by barriers to patient adherence, such as lack of efficacy, side effects and inconvenience. Recently published studies have investigated the safety and efficacy of a novel emollient foam (EF) formulation of clobetasol propionate (CP), a class I topical corticosteroid in psoriasis and atopic dermatitis.

OBJECTIVES

To summarize recent literature on CP EF foam, and to evaluate recent Phase II and III clinical trials of CP EF foam in psoriasis and atopic dermatitis.

METHODS

The MEDLINE (1950 - January 2008) database was searched using the following terms: 'clobetasol propionate foam', 'topical corticosteroids', 'topical glucocorticoids', 'psoriasis' and 'atopic dermatitis'. Results were evaluated for relevance and quality, and additional references were obtained from bibliographies of selected articles.

CONCLUSION

CP EF foam appears to be safe and effective for corticosteroid-responsive dermatoses in adults and children > or = 12 years of age. As compared to its hydroethanolic foam predecessor, CP EF presents a potential advance for patients who are less likely to tolerate alcohol-based foam. As alcohol-based foams can be irritating and cause stinging in non-hair-bearing areas, this new emollient formulation has the potential to widen the use of CP foam to more patients with atopic dermatitis and to more non-scalp body sites in patients with psoriasis.

Manipulation of corticosteroid release from a transiently supersaturated topical metered dose aerosol using a residual miscible co-solvent

PURPOSE

The creation of supersaturation transiently after application overcomes the issue of drug instability. However, if the solvents used to drive supersaturation evaporate too quickly, drug recrystallisation or rapid film drying can occur which will inhibit drug release. As such the effects of a residual solvent, poly(ethylene glycol) 400 (PEG), on the release, mobility and supersaturation kinetics of a transiently supersaturated formulation were studied.

MATERIALS AND METHODS

Metered dose aerosol (MDA) formulations consisting of hydrofluoroalkane 134a, ethanol, poly(vinyl pyrrolidone) K90, beclomethasone dipropionate (BDP), and 0%, 5% or 10% w/w PEG were prepared in canisters sealed with metered dose valves and tested for release and adhesion over time.

RESULTS

The addition of 10% PEG to the MDA formulation resulted in a significant reduction (p < 0.05) in steady state drug release rate (230.4 +/- 17.3 microg/cm(2)/h for 0% PEG MDA, 83.6 +/- 4.9 microg/cm(2)/h for 10% PEG MDA). The presence of PEG caused a delay in dose depletion (2 h for 0% PEG MDA versus 4 h for 10% PEG), retarded supersaturation kinetics and increased film drying time.

CONCLUSION

Whilst equivalent amounts of BDP were released, the residual solvent altered the drug release profile to achieve more constant delivery.

Control of transdermal permeation of hydrocortisone acetate from hydrophilic and lipophilic formulations

The purpose of this research was the preparation of four formulations containing hydrocortisone acetate (HCA) for topical application, including two aqueous systems (hydrophilic microemulsion and aqueous gel) and two systems with dominant hydrophobicity (hydrophobic microemulsion and ointment). The formulations were tested for the release and permeation of HCA across an animal membrane. The release of HCA was found comparable for the four systems. The two microemulsions promote permeation across an ex-vivo membrane, examined by means of a Franz cell. Hydrophobic microemulsion guarantees the highest solubility (2,370 microg/ml) and flux (133 microg/cm(2).h) of the drug, since it contains almost 40% Transcutol, a permeation enhancer. Gel and ointment provide lower solubility and flux, being the values, related to the ointment, the lowest ones (562 microg/ml and 0.4 microg/cm(2).h). Experimental results allow the conclusion that gel and ointment can be suitable when it is desirable to minimize absorption of topically applied HCA as to keep the drug restricted to the diseased area and prevent side effects of the systemic presence of HCA.

Emollient foam in topical drug delivery

Foams offer an innovative and more convenient means of topical drug delivery. The successful introduction of hydroalcoholic foams paved the way for the development of a new generation of foam products that provide skin barrier build-up and hydration. Such foams, designated as emollient foams consist of oil-in-water or water-in-oil emulsions with necessary excipients, such as non-ionic surfactants, gelling agents and foam adjuvants. Emollient foams can carry a broad variety of topical drugs, including water-soluble, oil-soluble and suspended active agents. This paper reviews emollient foam compositions and their physicochemical properties. It further accounts for the usability and functional advantages of emollient foam as a vehicle of topical drugs, including: i) improved usability, which affects treatment, compliance and, consequently, improves therapeutic results; ii) safety; iii) controllable drug delivery; iv) skin barrier build-up and hydration; and v) enhanced clinical efficacy.