Studies on nonionic surfactant bilayer vesicles of ciclopirox olamine

Assessment of Physical, Mechanical, Biopharmaceutical Properties of Emulgels and Bigel Containing Ciclopirox Olamine

Emulsions are thermodynamically unstable systems and it is difficult to produce biphasic formulations with large amounts of oil. The aim of our study was to prepare biphasic formulations containing 1% ciclopirox olamine and to determine the influence of the method of oil incorporation (without and with emulsifier and gelifier) on the physical (pH, particle size, rheological properties), mechanical, and biopharmaceutical properties of the formulations. It was found that the use of a poloxamer 407 gel as the hydrophase could result in a stable formulation when an oil with (EPG) or without an emulsifier (APG) or oleogel (OPG) was used as the oily phase. The results of the studies showed that the addition of an emulsifier (polysorbate 80) led to a decrease in the sol-gel temperature, a slower release of ciclopirox olamine, and a higher stability in the freeze–thaw test. However, regardless of the way the oil is incorporated, the particles are distributed in the same range and the antifungal activity against T. rubrum is the same. It is possible to create a biphasic formulation with a large amount of oil and poloxamer gel, but for greater stability, it is recommended to include an emulsifier in the composition.

Microsponge Based Gel of Tea Tree Oil for Dermatological Microbial Infections

Objective:

Tea Tree Oil (TTO), derived from Melaleuca alternifolia possesses broad spectrum antimicrobial potential. However, its therapeutic utility is impaired due to its high volatility, poor aqueous solubility and low stability in the presence of light, oxygen and temperature. The present study was attempted to investigate Ethyl Cellulose (EC) microsponges (MSs) as topical carriers for TTO to circumvent above mentioned limitations.

Methods:

TTO MSs were prepared using quasi emulsion solvent diffusion technique. The effect of formulation variables on the production yield, entrapment efficiency, particle size and drug release of MSs was investigated. The optimized MSs were dispersed into Carbopol 934 gel and evaluated for drug release, skin irritation, antibacterial activity and photostability.

Results:

Scanning electron microscopy revealed spherical and porous nature of TTO microsponges. The optimized MSs possessed particle size of 36.98 μm, percent entrapment efficiency of 93.12% and percent cumulative drug release of 79.18%, respectively. MS-loaded gels were found nonirritant. In addition, TTO loaded MS gels exhibited good stability. Antimicrobial effect of TTO MS gel showed broader zones of inhibition in comparison to TTO gel.

Conclusion:

The findings of our study suggest that MS loaded gel could prove alternative to conventional antibacterial formulations for dermatological microbial infections.

Nanoparticles for topical drug delivery: Potential for skin cancer treatment

Nanoparticles offer new opportunities for the treatment of skin diseases. The barrier function of the skin poses a significant challenge for nanoparticles to permeate into the tissue, although the barrier is partially compromised in case of injury or inflammation, as in the case of skin cancer. This may facilitate the penetration of nanoparticles. Extensive research has gone into developing nanoparticles for topical delivery; however, relatively little progress has been made in translating them to the clinic for treating skin cancers. We summarize the types of skin cancers and practices in current clinical management. The review provides a comprehensive outlook of the various nanoparticle technologies tested for topical therapy of skin cancers and summarizes the obstacles that impede its progress from the bench-to-bedside. The review also aims to provide an understanding of the pathways that govern nanoparticle penetration into the skin and a critical analysis of the approaches used to study nanoparticle interactions within the tissue.

In vitro skin models as a tool in optimization of drug formulation

(Trans)dermal drug therapy is gaining increasing importance in the modern drug development. To fully utilize the potential of this route, it is important to optimize the delivery of active ingredient/drug into/through the skin. The optimal carrier/vehicle can enhance the desired outcome of the therapy therefore the optimization of skin formulations is often included in the early stages of the product development. A rational approach in designing and optimizing skin formulations requires well-defined skin models, able to identify and evaluate the intrinsic properties of the formulation. Most of the current optimization relies on the use of suitable ex vivo animal/human models. However, increasing restrictions in use and handling of animals and human skin stimulated the search for suitable artificial skin models. This review attempts to provide an unbiased overview of the most commonly used models, with emphasis on their limitations and advantages. The choice of the most applicable in vitro model for the particular purpose should be based on the interplay between the availability, easiness of the use, cost and the respective limitations.

Formulation and evaluation of optimized oxybenzone microsponge gel for topical delivery

Background. Oxybenzone, a broad spectrum sunscreen agent widely used in the form of lotion and cream, has been reported to cause skin irritation, dermatitis, and systemic absorption. Aim. The objective of the present study was to formulate oxybenzone loaded microsponge gel for enhanced sun protection factor with reduced toxicity. Material and Method. Microsponge for topical delivery of oxybenzone was successfully prepared by quasiemulsion solvent diffusion method. The effects of ethyl cellulose and dichloromethane were optimized by the 3² factorial design. The optimized microsponges were dispersed into the hydrogel and further evaluated. Results. The microsponges were spherical with pore size in the range of 0.10–0.22 µm. The optimized formulation possesses the particle size and entrapment efficiency of 72 ± 0.77 µm and 96.9 ± 0.52%, respectively. The microsponge gel showed the controlled release and was nonirritant to the rat skin. In creep recovery test it had shown highest recovery indicating elasticity. The controlled release of oxybenzone from microsponge and barrier effect of gel result in prolonged retention of oxybenzone with reduced permeation activity. Conclusion. Evaluation study revealed remarkable and enhanced topical retention of oxybenzone for prolonged period of time. It also showed the enhanced sun protection factor compared to the marketed preparation with reduced irritation and toxicity.

Potentiating antimicrobial efficacy of propolis through niosomal-based system for administration

Background

Propolis is a multicomponent active, complex resinous substance collected by honeybees (Apis mellifera) from a variety of plant sources. This study was designed to improve the antimicrobial efficacy of propolis by engineering a niosomal-based system for topical application.

Methods

Propolis was extracted in ethanol and screened for total polyphenol content. Propolis-loaded niosomes (PLNs) were prepared with varying concentrations of Span 60 and cholesterol. The PLNs were evaluated for physicochemical parameters, namely, vesicle size, entrapment efficiency, zeta potential, surface topography and shape, and stability, followed by screening for in vitro antimicrobial activity. The PLNs were formulated into propolis niosomal gel (PNG) using Carbopol P934 base and subjected to ex vivo skin deposition study.

Results

The ethanolic extract of propolis had high polyphenolic content (270 ± 9.2 mg GAE/g). The prepared PLNs showed vesicle size between 294 nm and 427 nm, and the percent entrapment in the range of 50.62–71.29% with a significant enhancement in antimicrobial activity against Staphylococcus aureus and Candida albicans. Enhanced antimicrobial activity of PLNs was attributed to the ability of niosomes to directly interact with the bacterial cell envelop thereby facilitating the diffusion of propolis constituents across the cell wall. The formulated PNG exhibited a twofold better skin deposition due to improved retention of niosomes in the skin.

Conclusion

The findings indicate that the engineering of a niosomal-based system for propolis enhanced its antimicrobial potential through topical application.

Vancomycin-eluting niosomes: a new approach to the inhibition of staphylococcal biofilm on abiotic surfaces

A new vancomycin (VCM)-eluting mixed bilayer niosome formulation was evaluated for the control of staphylococcal colonization and biofilm formation on abiotic surfaces, a niosome application not explored to date. Cosurfactant niosomes were prepared using a Span 60/Tween 40/cholesterol blend (1: 1: 2). Tween 40, a polyethoxylated amphiphile, was included to enhance VCM entrapment and confer niosomal surface properties precluding bacterial adhesion. VCM-eluting niosomes showed good quality attributes including relatively high entrapment efficiency (∼50%), association of Tween 40 with vesicles in a constant proportion (∼87%), biphasic release profile suitable for inhibiting early bacterial colonization, and long-term stability at 4°C for a 12-month study period. Niosomes significantly enhanced VCM activity against planktonic bacteria of nine staphylococcal strains. Using microtiter plates as abiotic surface, VCM-eluting niosomes proved superior to VCM in inhibiting biofilm formation, eradicating surface-borne biofilms, inhibiting biofilm growth, and interfering with biofilm induction by VCM subminimal inhibitory concentrations. Data suggest dual functionality of cosurfactant VCM-eluting niosomes as passive colonization inhibiting barrier and active antimicrobial-controlled delivery system, two functions recognized in infection control of abiotic surfaces and medical devices.

Investigation of ethyl cellulose microsponge gel for topical delivery of eberconazole nitrate for fungal therapy

Background: The aim of the study was to investigate ethyl cellulose microsponges as topical carriers for the controlled release and cutaneous drug deposition of eberconazole nitrate (EB). Materials & method: EB microsponges were prepared using the quasiemulsion solvent diffusion method. The effect of formulation variables (drug:polymer ratio, internal phase volume and amount of emulsifier) and process variables (stirring time and stirring speed) on the physical characteristics of microsponges were investigated. The optimized microsponges were dispersed into a hydrogel and evaluated. Results & discussion: Spherical and porous EB microsponge particles were obtained. The optimized microsponges possessed particle size, drug content and entrapment efficiency of 24.5 µm, 43.31% and 91.44%, respectively. Microsponge-loaded gels demonstrated controlled release, nonirritancy to rat skin and antifungal activity. An in vivo skin deposition study demonstrated fourfold higher retention in the stratum corneum layer as compared with commercial cream. Conclusion: Developed ethyl cellulose microsponges could be potential pharmaceutical topical carriers of EB in antifungal therapy.