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.

The Influence of pH Values on the Rheological, Textural and Release Properties of Carbomer Polacril® 40P-Based Dental Gel Formulation with Plant-Derived and Synthetic Active Components.

The physicochemical properties, especially pH value of dental medicines, have significant influence on the health of oral cavity tissues. The pH of formulations should correspond to the value of saliva pH (5.5-8.0). For carbomer-based gels, the required pH value is obtained by neutralizing them with alkaline components, which leads to their structuring (thickening). This affects the physical properties of the gel, its residence time at the application site and the rate of release of active pharmaceutical ingredient. Therefore, the main purpose of this study is to evaluate the rheological, textural, and biopharmaceutical properties of Carbomer Polacril® 40P-based dental gel depending on the pH value. Evaluation of the rheological properties of gel preparations were performed by measuring the structural viscosity of the samples as a function of pH and temperature. The textural properties of the gel were evaluated by performing tests regarding back extrusion and spreadability. Carbomer Polacril® 40P-based gels haven't shown noticeable thixotropic behavior, and were characterized by plastic flow in the whole studied pH range. The structural viscosity at the selected average pH value hasn't differed at storage (25 °C) and application (37 °C) temperature. Texture studies of dental gels have shown a strong correlation with rheoparameters. Their rheological behavior and textural properties haven't changed significantly between the pH range of 5.5-6.6. The relatively narrow range of working pH values does not affect the change in the viscosity of the preparation significantly and, consequently, does not affect the release of APIs from the developed Carbomer Polacril® 40P-based dental gel.

Topical antifungal bigels: Formulation, characterization and evaluation.

Bigels with antifungal substances, ciclopirox olamine and terbinafine hydrochloride, were made of hydrogel (poloxamer 407 gel) and oleogel (polyethylene and liquid paraffin mixture). Prepared bigels were found physically stable at room temperature for six months and at least four months at 40 °C. Released amount of drug decreased when oleogel concentration in the formulation increased. Release test results depended on the insertion place of active substances. The amount of released substance was highest when ciclopirox olamine was incorporated in both phases in an equal quantity, and terbinafine hydrochloride in oleogel or in hydrogel. All formulations showed great inhibition of Microsporum canis. Thus, bigels with ciclopirox olamine and terbinafine hydrochloride are a promising dosage form for topical use.

MODELLING AND BIOPHARMACEUTICAL EVALUATION OF CICLOPIROX OLAMINE GELS.

The ciclopirox olamine (CPO) has a broad antimicrobial profile including dermatophytes, yeasts and is used in various pharmaceutical forms. The aim of this study is to evaluate the quality of the CPO gels according to biopharmaceutial tests in vitro and antifungal activity assay. Hydroxypropyl cellulose, chitosan and poloxamer 407 were selected as agents gelificants. The effects of gelling agent properties and concentration on the consistency and flow characteristics have been studied by rheometer. CPO release rates from gel were measured with Franz type diffusion cells. The antifungal activity of gels was tested using agar well diffusion technique. The results of the experimental study have shown that the rheological properties of the medications depend on the selected gelling agent and the amount of it. The higher amounts of CPO were released from the poloxamer 407 gels. Though all tested CPO gels showed great inhibition of Microsporn canis.