Simultaneous formulation of terbinafine and salvia monoterpenes into chitosan hydrogel with testing biological activity of corresponding dialysates against C. albicans yeast.

This work was aimed at a progressive formulation of drugs into chitosan hydrogels. It was taken into consideration that a therapeutic effect of the drugs could be enhanced by a combination of natural compounds with chemical (synthetic) drugs. In this work, sage essential oil (SEO) bicyclic monoterpenes with antiflogistic, antiseptic, and antimycotic properties were combined with terbinafine (TB) having a strong antimycotic activity. Detail optimization of the hydrogel-drugs composition (SEO monoterpenes, TB, chitosan, and polysorbate 80 concentrations), based on permeation experiment and UV absorption/GC-MS analysis of permeated species (eucalyptol, camphor, borneol, thujone, TB) in dialysates, was made. Concerning the active drugs formulation, an optimum concentration of TB was set at the level providing maximum release of the SEO monoterpenes. In vitro activity of the dialysates from the optimized hydrogel was tested against Candida albicans showing that a minimum inhibition concentration was significantly exceeded. The experimental results revealed that the chitosan hydrogel was suitable for the simultaneous formulation of the natural drugs (SEO) with chemical drug (TB) resulting in the preparation with acceptable stability, required gel properties, and significant biological activity. Such preparation should be effective in an antimycotic dermal use.

Formulation of sage essential oil (Salvia officinalis, L.) monoterpenes into chitosan hydrogels and permeation study with GC-MS analysis.

This study deals with the formulation of natural drugs into hydrogels. For the first time, compounds from the sage essential oil were formulated into chitosan hydrogels. A sample preparation procedure for hydrophobic volatile analytes present in a hydrophilic water matrix along with an analytical method based on the gas chromatography coupled with the mass spectrometry (GC-MS) was developed and applied for the evaluation of the identity and quantity of essential oil components in the hydrogels and saline samples. The experimental results revealed that the chitosan hydrogels are suitable for the formulation of sage essential oil. The monoterpene release can be effectively controlled by both chitosan and caffeine concentration in the hydrogels. Permeation experiment, based on a hydrogel with the optimized composition [3.5% (w/w) sage essential oil, 2.0% (w/w) caffeine, 2.5% (w/w) chitosan and 0.1% (w/w) Tween-80] in donor compartment, saline solution in acceptor compartment, and semi-permeable cellophane membrane, demonstrated the useful permeation selectivity. Here, (according to lipophilicity) an enhanced permeation of the bicyclic monoterpenes with antiflogistic and antiseptic properties (eucalyptol, camphor and borneol) and, at the same time, suppressed permeation of toxic thujone (not exceeding its permitted applicable concentration) was observed. These properties highlight the pharmaceutical importance of the developed chitosan hydrogel formulating sage essential oil in the dermal applications.

[Formulation of benzethonium chloride into gels]. / Formulácia benzetóniumchloridu do gélov.

This study is focused on the preparation of gels with antimicrobial effects. A quaternary ammonium salt, benzethonium chloride, in a concentration of 0.01-0.5% (w/w) was employed as the drug. The humectant employed was propylene glycol in concentrations of 5% and 10% (w/w). Two types of polymers, chitosan and hydroxyethyl cellulose, in the same concentrations of 2.5% (w/w), were used for gel preparation. Finally the flow properties, rheological parameters and pH values of the gels were evaluated. Based on the obtained results, the samples of the gels prepared on the basis of chitosan and hydroxyethyl cellulose, which have the following optimum composition shown below, were found: 2,5% (w/w) CHIT + 0,5% (w/w) BZCl + 10% (w/w) PG; 2,5% (w/w) HEC + 0,5% (w/w) BZCl + 5% (w/w) PG.

[Influence of excipients on caffeine permeation from gels]. / Vplyv pomocných látok na permeáciu kofeínu z gélov.

UNLABELLED: The subject of this paper is a study of the influence of excipients on caffeine permeation from dermal semisolids drugs. Due to its advantageous properties, caffeine can be successfully used in dermal hydrogels. The choice of excipients from the group of humectants and cationic surfactants also plays an important role. The excipients should ensure long-term stability of hydrogels and the best permeation of the drug from gels. In particular, the influence of various excipients on caffeine permeation from gels and at the same time their influence on rheological properties of hydrogels were investigated. Based on the obtained results, the following optimal composition of caffeine gel was determined: 2.5 % chitosan + 0.1 % caffeine + 10 % propylenglycol + 0.1 % benzyldimethylhexadecylammonium chloride. KEYWORDS: caffeine hydrogels permeation rheological parameters.

[Influence of temperature and concentration of a surfactant on pharmaceutical availability]. / Vplyv teploty a koncentrácie tenzidu na farmaceutickú dostupnost lieciva.

This study aimed to analyze the influence of surfactant concentration and temperature on drug liberation from hydrogels and their flow properties. The surfactant benzethonium chloride (BZCl) was used in concentrations of 0.01, 0.1 and 0.5 % (w/w), while the drug chlorhexidine dihydrochloride (CHX) was used in a concentration of 0.1 % (w/w). Chitosan (CHIT) in 2.5 % (w/w) concentration was used as a gel-creating substance. The drug and surfactant liberation were evaluated within the temperature range of 25-40 °C. The largest amounts of both of them were liberated at the temperature of 40 °C. Through the concentration changes it was possible to obtain statistically significant differences (P < 0.05) between the liberation of CHX and BZCl. An analysis of the flow properties revealed that the character of the plastic system was not influenced by the changing concentration of the surfactant. The experimental results led to the conclusion that the optimum composition of the gel was as follows: 2.5 % (w/w) CHIT + 0.1 % (w/w) CHX + 0.01 % (w/w) BZCl.

[Evaluation of liberation of caffeine from dermal semisolids drugs]. / Hodnotenie liberácie kofeínu z dermálnych polotuhých liekov.

The paper deals with formulation of caffeine into dermal semisolid dosage forms - hydrogels. Caffeine was chosen as a model drug because its properties can be successfully used just in hydrogels. Protective and tranquilization effects can be used in the preparations for sunbathing, and its lipolytic and regenerative effect can be used for the treatment of androgenic alopecia or cellular bioprotection. The aim of the study was to investigate the influence of different concentrations of chitosan and caffeine on the liberation of gels. Besides, stability of the prepared samples was evaluated by means of the evaluation of their rheological parameters. Based on the obtained results, there was determined the optimal drug concentration - caffeine 0.2% (w/w) and also the gel forming substance - chitosan 2.3% (w/w).

[Formulation of salvia-containing gels]. / Formulácia gélov s obsahom salvie lekárskej.

The trend during the past years is to prefer natural drugs to synthetically prepared medicines. Due to its important antiphlogistic, antiseptic and antihidrotic effects, Salvia officinalis L. has a wide use in medicine, pharmacy and cosmetics in various dosage forms. The aim of this research was the formulation of Salvia officinalis L. in the form of a tincture to hydrogels. Gels were parallelly prepared on the basis of the natural polymer chitosan and the synthetic polymer Carbopol 940. The evaluation was focused on the influence of the anionic polymer and the cationic polymer in different concentrations on hydrogel flow properties. Glycerol functioning as a humectant was used in various percentage ratios. On the basis of the determination of rheological parameters and flow curves lapses the most suitable hydrogel from the application point of view was selected.