Emollient foam in topical drug delivery

Localized Delivery of Liquid Fertilizer in Coarse-Textured Soils Using Foam as Carrier

Agrochemicals and fertilizers are central to modern agriculture and are credited with the large increase of crop yield as a part of the Green Revolution of the 1960’s. Timely and targeted fertilizer application to crop root zones enhances effectiveness and reduces unintended release to the environment. This is particularly important for highly mobile liquid fertilizers (e.g., nitrate) that can be mobilized with infiltrating water to bypass root-bearing soil volumes. We report a novel liquid fertilizer delivery method using foam as carrier. The high degree of control and mechanical stability of liquid fertilizer foam (defined dispersed gas bubbles in a continuous liquid phase) injection into coarse soils (most susceptible to preferential flows) is proposed a novel delivery method to targeted root zone volumes at concentrations and geometry that promote uptake and reduces losses. This note and preliminary communication meant to serve a proof of concept report comparing foam and conventional liquid fertilizer applications. The results indicate that foam-delivery reduced fertilizer leaching thus improving its retention in soil for similar flow conditions of liquid delivery. Theoretical estimates suggest that the effects of fertilizer retention could be enhanced in more localized (3-D) injection of foam fertilizers and other agrochemicals thus enhancing agronomic efficiency and reducing environmental risk of contamination.

Drug Carriers: A Review on the Most Used Mathematical Models for Drug Release

Carriers are protective transporters of drugs to target cells, facilitating therapy under each points of view, such as fast healing, reducing infective phenomena, and curing illnesses while avoiding side effects. Over the last 60 years, several scientists have studied drug carrier properties, trying to adapt them to the release environment. Drug/Carrier interaction phenomena have been deeply studied, and the release kinetics have been modeled according to the occurring phenomena involved in the system. It is not easy to define models’ advantages and disadvantages, since each of them may fit in a specific situation, considering material interactions, diffusion and erosion phenomena, and, no less important, the behavior of receiving medium. This work represents a critical review on main mathematical models concerning their dependency on physical, chemical, empirical, or semi-empirical variables. A quantitative representation of release profiles has been shown for the most representative models. A final critical comment on the applicability of these models has been presented at the end. A mathematical approach to this topic may help students and researchers approach the wide panorama of models that exist in literature and have been optimized over time. This models list could be of practical inspiration for the development of researchers’ own new models or for the application of proper modifications, with the introduction of new variable dependency.

In Vitro Evaluation of a Foamable Microemulsion Towards an Improved Topical Delivery of Diclofenac Sodium

Topical microemulsion (ME) might provide a novel and advanced transdermal delivery system due to the enhances of drug solubility and permeability across the stratum corneum. Foams are topical delivery systems that have excellent patient compliance, acceptability, and preference. Therefore, this study aimed to investigate a foamable microemulsion as an alternative topical and transdermal dosage form for diclofenac sodium (DS). The physicochemical properties (optical clarity, percentage transmittance, homogeneity, consistency of formulation, particle size, zeta potential, conductivity, viscosity, and morphology, etc.) of the DS-loaded ME were investigated. The foam stability of both drug-free ME and DS-loaded ME was measured. The foam quality was evaluated, and the chemical stability over 90 days was determined. Franz diffusion cells were employed to assess the in vitro drug release of a foamed DS-loaded ME and compared with a commercial topical product. A foamable and stable DS-loaded ME that maintained small particle sizes and constant zeta potential and was transparent and translucent in appearance after 90 days was successfully produced. The foam of the DS-loaded ME was physically more stable compared to the drug-free foam. The foam had an increased drug release rate compared to the commercial product. The foamable DS-loaded ME has a great potential to enhance the transdermal delivery of DS after topical administration. Foamed DS-loaded ME is a promising alternative to the current topical formulation of DS.

Complying with the Guideline for Quality and Equivalence for Topical Semisolid Products: The Case of Clotrimazole Cream

Semisolids constitute a significant proportion of topical pharmaceutical dosage forms available on the market, with creams being considered profitable systems for releasing active substances into the skin. This work aimed at the development of a generic Clotrimazole topical cream, based on the assumptions that assist the development of such formulations. First, the critical parameters to obtain a final formulation as similar as possible to the reference product were defined. Then, the percentages of cetyl palmitate and octyldodecanol were identified as critical variables and chosen for optimization in further studies. A "quality by design" approach was then used to identify the effect of process variability on the structural and functional similarity (Q3) of the generic product qualitatively (Q1) and quantitatively (Q2). A two-factor central composite orthogonal design was applied and eleven different formulations were developed and subjected to physicochemical characterization and product performance studies. The results were used to estimate the influence of the two variables in the variation of the responses, and to determine the optimum point of the tested factors, using a design space approach. Finally, an optimized formulation was obtained and analysed in parallel with the reference. The obtained results agreed with the prediction of the chemometric analysis, validating the reliability of the developed multivariate models. The in vitro release and permeation results were similar for the reference and the generic formulations, supporting the importance of interplaying microstructure properties with product performance and stability. Lastly, based on quality targets and response constraints, optimal working conditions were successfully achieved.

General practice recommendations for the topical treatment of psoriasis: a modified-Delphi approach

BACKGROUND

Although GPs are usually the first port of call for patients with psoriasis, there is a lack of consistent and up-to-date clinical recommendations for interventions for patients with mild-to-moderate disease.

AIM

To provide practical recommendations for GPs to optimise psoriasis treatment with topical therapies in four key areas: patient identification; treatment decision making with topical theory; topical treatment outcomes; and optimising patient adherence.

DESIGN & SETTING

A consensus-seeking programme (modified-Delphi approach) was undertaken to assess the literature and develop recommendations for GPs, based on evidence and expert opinion.

METHOD

Three dermatologists compiled 47 questions that were subsequently ranked and refined according to clinical relevance or importance using an online survey. Thereafter, 19 dermatologists from different European countries developed statements and clinical recommendations for the top seven ranked topical treatment and GP-relevant questions based on literature research and clinical experience. The final recommendations were based on 100% agreement among a final panel of seven experts.

RESULTS

The clinical effectiveness, fast onset of action, tolerability, cosmetic acceptability, and practicability of topical therapy, in addition to good physician-patient communication, are important for optimising patient adherence and maximising efficacy. Topical treatments combining corticosteroids and vitamin D analogues (administered as fixed combination) are well-established first-line treatments in mild-to-moderate psoriasis.

CONCLUSION

Simple but detailed practical guidance is provided, which is formed from evidence and expert clinical recommendations, to assist GPs with the optimal use of topical agents based on efficacy, tolerability, disease severity, site of psoriasis, patient lifestyle and preferences, and intended duration of treatment.

Evaluating FMX-101 as a promising therapeutic for the treatment of acne

INTRODUCTION

Oral minocycline is a mainstay of therapy for moderate-to-severe acne; however, systemic side effects which include hepatotoxicity, lupus-like syndrome, drug hypersensitivity syndrome, autoimmune hepatitis, polyarteritis nodosa, gastrointestinal side effects and skin hyperpigmentation are of concern. Topical antibiotics commonly used in acne, such as erythromycin and clindamycin, present high P. acnes resistance rates which has opened the market for new topical antibiotics. FMX-101 is a novel topical minocycline foam that has shown promising results in phase I, II and III trials for the treatment of moderate-to-severe acne with a better safety profile than oral minocycline.

AREAS COVERED

The author provides an overview FMX-101 including its clinical efficacy and safety. The author then provides their expert opinion on this treatment and its potential for the treatment option for acne.

EXPERT OPINION

The topical foam formulation of FMX-101 has been shown to reduce both inflammatory and non-inflammatory lesions and to improve IGA scores in patients with moderate-to-severe acne without significant systemic absorption thus limiting associated side effects. Overall, the proven efficacy and safety profile of FMX-101, together with the low systemic absorption, high skin tolerability and cosmetically acceptable foam formulations render this novel therapy an important addition to the acne treatment armamentarium.

Foam drainage placed on a thin porous layer

Drainage of foams placed on porous substrates has only recently been theoretically investigated (O. Arjmandi-Tash, N. Kovalchuk, A. Trybala, V. Starov, Foam Drainage Placed on a Porous Substrate, Soft Matter, 2015, 11(18), 3643-3652), where an equation describing foam drainage (with non-slip boundary conditions on the liquid-air interfaces) was combined with that of imbibition of liquid into the thick porous substrate. Foam-based applications have been used as a method of drug delivery, which is a recent and promising area of research related to application of medicinal products onto the skin or hair, which are both thin porous layers. A theory of foam drainage (taking into account surface viscosity) placed on a completely wettable thin porous layer is developed: the rate of foam drainage and imbibition inside the porous layer and other characteristics of the process are predicted. The "effective slip" caused by the surface viscosity increased a movement of the top boundary of the foam. The theoretical predictions are compared with experimental observations of foam drainage placed on thin porous layers. The comparison showed a reasonable agreement between the theoretical predictions and experimental observations. One of the phenomena during foam application is the possibility of a build-up of a free liquid layer on the foam/porous layer interface, which can be very useful for applications. Three different regimes of spreading/imbibition process have been predicted. Conditions and durations of free liquid layer formation have been theoretically predicted and compared with experimental observations.

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 novel topical minocycline foam for the treatment of moderate-to-severe acne vulgaris: Results of 2 randomized, double-blind, phase 3 studies

BACKGROUND

FMX101 4% is a topical minocycline foam for the treatment of moderate-to-severe acne.

OBJECTIVE

Evaluate the efficacy and safety of FMX101 4% in treating moderate-to-severe acne vulgaris.

METHODS

Two identical phase 3 studies were conducted. Subjects were randomized 2:1 to once-daily FMX101 4% or foam vehicle for 12 weeks. The coprimary end points were the change in inflammatory lesion count from baseline and the rate of treatment success according to the Investigator's Global Assessment (a score of 0 or 1 for clear or almost clear, with a ≥2-grade improvement) at week 12.

RESULTS

A total of 961 subjects were enrolled (study 04, N = 466; study 05, N = 495). Compared with vehicle, FMX101 4% demonstrated a significantly greater reduction in inflammatory lesions in both studies (P < .05) and a greater rate of treatment success in study 05 according to the Investigator's Global Assessment (P < .05). Pooled analyses of the 2 studies demonstrated statistical significance for both coprimary end points (all P < .05). Noninflammatory lesion count was also significantly reduced with FMX101 4% versus with vehicle in both studies. FMX101 4% was generally safe and well tolerated. Skin-related adverse events were reported in less than 1% of subjects treated with FMX101 4%.

LIMITATIONS

Longer-term efficacy and safety outcomes are needed (ongoing).

CONCLUSION

FMX101 4% topical minocycline foam significantly reduced both inflammatory and noninflammatory lesions and improved Investigator's Global Assessment scores in patients with moderate-to-severe acne.

A Phase II, Randomized, Double-Blind Clinical Study Evaluating the Safety, Tolerability, and Efficacy of a Topical Minocycline Foam, FMX103, for the Treatment of Facial Papulopustular Rosacea

OBJECTIVE

Our objective was to demonstrate the safety, tolerability, and efficacy of a minocycline foam, FMX103, in the treatment of moderate-to-severe facial papulopustular rosacea.

METHODS

This was a phase II, randomized, double-blind, multicenter study. Healthy subjects aged ≥ 18 years with moderate-to-severe rosacea that had been diagnosed ≥ 6 months previously and with ≥ 12 inflammatory facial lesions were randomized (1:1:1) to receive once-daily 1.5% FMX103, 3% FMX103, or vehicle for 12 weeks. The primary endpoint was the absolute change in inflammatory lesion count at week 12. Other assessments included grade 2 or higher Investigator's Global Assessment (IGA) improvement, IGA "clear" or "almost clear" (IGA 0/1), clinical erythema, and safety/tolerability. Safety and efficacy were evaluated at weeks 2, 4, 8, and 12, with a safety follow-up at week 16.

RESULTS

A total of 232 subjects were randomized; 213 completed the study. At week 12, inflammatory lesion count reduction was significantly greater for the 1.5 and 3% FMX103 doses than for vehicle (21.1 and 19.1 vs. 7.8, respectively; both p < 0.001). Both doses were significantly better than vehicle for achieving grade 2 or higher IGA improvement and assessment of "clear" or "almost clear." Both doses appeared generally safe and well tolerated. In total, 11 (4.7%) subjects reported treatment-related treatment-emergent adverse events (TEAEs); all but one (eye discharge) were dermal related, and all resolved by study end. No treatment-related systemic TEAEs were reported. Four subjects discontinued the study because of TEAEs (3% FMX103, n = 3; vehicle, n = 1).

CONCLUSION

Topical minocycline foam, FMX103, appeared to be an effective, safe, and well tolerated treatment for moderate-to-severe papulopustular rosacea. These results support further investigation in larger clinical trials. CLINICALTRIALS.

GOV IDENTIFIER

NCT02601963.

Expansible thermal gelling foam aerosol for vaginal drug delivery

Vaginal delivery of antimicrobial drugs is the most effective method for the local treatment of the vaginal infections. However, current vaginal drug delivery systems (VDDS), including gel, lotion, aerosol and cream, are suffering from low penetration in the deep vaginal rugae and easy elimination by self-cleaning of vaginal canal. To address these issues, a foam aerosol based on the thermal transformation was designed to improve penetration efficiency and achieve the extended retention. The expansible thermal gelling foam aerosol (ETGFA) consisting of thermal sensitive matrix, silver nanoparticle, adhesive agent and propellant, was optimized by evaluations of precursor viscosity, foam expansion, thermal gelation, gel adhesiveness, antimicrobial effects and tissue irritation. The ETGFA would penetrate to the deep vaginal rugae to cover the infectious sites by foam expansion. Drug leakage was intended to be avoided by the thermal gelation at physiological temperature before foam collapse. The gel could be retained in the vaginal canal for extended time due to its superior adhesiveness when compared to the commercial gel Asimi®. The ETGFA provided extended drug release for over 4 h and maintained effective drug concentrations at the infectious sites. The ETGFA containing silver nanoparticles showed dose-dependent antimicrobial effects on the vaginal floras and irritation reduction to the vaginal tissues. The results demonstrated that the ETGFA could overcome the limitations of conventional dosage forms, including poor drug penetration, carrier retention and patient compliance and satisfied the requirements for vaginal drug delivery.

Importance of Vehicles in Topical Treatment of Fungal Infections

Topical drug therapies are commonly used to manage dermatologic diseases and their manifestations in the skin, hair, nails, and mucous membranes. Compared with systemic treatment, topical drug delivery provides 2 notable benefits in the management of skin diseases. In addition to delivering the active drug, a well-designed vehicle can have supportive effects on the skin, whereas a poorly designed vehicle can have detrimental effects. In many cases, the same active drug is available in several dosage forms, offering the prescriber the ability to tailor treatment to the patient's unique presentation and needs.

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.

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.

Comparison of safety and efficacy of foam-based versus solution-based ciprofloxacin for acute otitis externa

OBJECTIVE

To compare and evaluate the efficacy and safety of a foam-based antibiotic formulation in the treatment of acute otitis externa (AOE) with the more conventional solution-based formulation.

STUDY DESIGN

Phase 2, open-label, randomized controlled trial.

SETTING

Multicenter.

SUBJECTS AND METHODS

Sixty-three eligible adult patients with unilateral AOE were randomly assigned to one of two treatment groups: an experimental 0.3 percent foam-based ciprofloxacin, (FoamOtic Cipro) or 0.3 percent solution-based ciprofloxacin (Ciloxan). All patients received the same dose regime (twice daily for 7 days). The primary efficacy variable was response to therapy (cure) in the test-of-cure visit. Secondary variables included improvement of the disease symptoms otalgia, tenderness, edema, and otorrhea.

RESULTS

Sixty-four patients were enrolled in the study. Seven patients were excluded from the per-protocol analysis due to major deviations from the protocol. Per-protocol analysis (n = 57) showed that cure was achieved in all the patients (P = 1.000). No significant differences were found between groups for symptomatic relief, resolution of otic discharge, or onset of pain reduction. Both treatments were found to be highly efficacious and safe, demonstrating the noninferiority of the experimental drug.

CONCLUSION

Foam-based ciprofloxacin is a safe and an effective new treatment for AOE.