Biocompatibility investigation of different pharmaceutical excipients used in liquid dosage forms.

Aqueous pharmaceutical solutions provide prosperous living conditions for microbiological agents. In order to eliminate these microbes, we use preservatives which can harm human cells as well. Their cytotoxicity is concentration-dependent and the aim of our study was to find how other pharmaceutical excipients modify the cytotoxic attributes of preservatives. We tested the following compounds: methylparaben, benzalkonium chloride, polysorbate 20, Labrasol® and hydroxyethyl cellulose. The MTT tests indicated that surfactants increase the cytotoxicity while polymers may decrease it in some cases.

Hepatoprotective effects of a self-micro emulsifying drug delivery system containing Silybum marianum native seed oil against experimentally induced liver injury.

The main purpose of this study was to certify the effect of native silymarin oil (SM-oil) formulated in a self-microemulsifying drug delivery system (SMEDDS). The optimal formulation was 25% of SM-oil, 33.3 % of Cremophor RH40, 20% of Transcutol HP, 16.6% of Labrasol and 5% of Capryol 90. In this novel formulation the SM-oil was the active substance and the lipid part. The in vivo study examined the preventive effects of SMEDDS containing SM native seeds oil against carbon tetrachloride (CC14) induced hepatotoxicity in mice. Determination of alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels and also liver histology investigations have been done. The liver antioxidant status was determined with the concentrations of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione (GSH) hepatic lipid peroxidation was examined and expressed in terms of malondialdehyde (MDA) content. The plasma levels of AST and ALT significantly diminished by pre-treatment with 500 mg/kg and 1000 mg/kg SMEDDS. The pre-treatment with 500 mg/kg and 1000 mg/kg SMEDDS increased GSH level by about 6% respectively 24% compared to the CC14 group. Due to preventive administration of 500 mg/kg and 1000 mg/kg of SMEDDS in the intoxicated animals, MDA levels were reduced by 22% respectively 58%. Also, an insignificant rise by almost 17% and 19% in the animals treated with the both doses of SMEDDS could be noticed. It can be concluded that hepatotoxicity may be avoided by the oral application of our formulation.

A comparative study on dyslipidaemia inducing diets in various rat strains.

In our experiments we compared the serum lipoprotein lipid composition of Fischer 344 (F344) and Long-Evans (LE) inbred rats as well as of their hybrid FLF(1) from both sexes after feeding them for 2, 4 and 8 weeks with different diets. The following diets were used: 1) standard diet marked as CRLT/N; 2) diet reach in butter marked as BR; 3) diet containing cholesterol, sodium cholate and methylthiouracil marked as CR; 4) diet marked as BRC, which is the Hartroft-Sós diet modified by our research group consisting of the diets BR and CR. The latter diet was the most effective, because within two weeks the level of serum total cholesterol, LDL-cholesterol, HDL-cholesterol and triglyceride in the F344 female rats increased 8, 30, 4 and 8 times, respectively. The male rats of the Long-Evans strain showed moderately increased values while the FLF(1) female hybrids derived from the hybridization of LE males and F344 females had values closer to those of the mother strain. Despite the fact that during this time the LDL/HDL ratio increased from 0.06 to 2.97 and the PON-1 activity decreased to one-third, a significant lipid deposition could not be shown in the wall of the abdominal aorta even two months later. Our experimental model is suitable for the chemoprevention of dyslipidaemia or rapid testing of molecules chosen for its treatment.

Assessment of the hemolytic activity and cytotoxicity of different PEG-based solubilizing agents.

The hemolytic activity and the cytotoxicity of PEG-based solubilizing agents on Caco-2 monolayer were investigated. In vitro tests can predict the irritancy potential and the delayed toxicity of the surfactants. There were significant concentration dependent differences between the result of the MTT (3-(4,5-dimethylthiazol-2-yl))-2,5-diphenyltetrazolium bromide) test and the data of the hemolytic activity test. Our investigations show that safer and more applicable tensides can be selected in order to form a more biocompatible medicament.

Cytotoxicity testing of carrier-based microcomposites for DPI application.

Inhalation is an attractive delivery route for systemic and local therapy. High local drug concentrations may permit non-invasive delivery, lower therapeutic doses, reduced systemic side-effects, and reduced metabolic degradation of the drug in the liver. In our earlier study, carrier-based microcomposites were prepared and investigated. The present study introduces studies of the cytotoxicity of meloxicam-containing microcomposites on monolayers of Calu-3 cells, in order to acquire information on its availability in pulmonary formulations. By relating cytotoxicity and drug dissolution, the appropriate amount of meloxicam for dry powder inhalation could be determined.

Evaluation of the cytotoxicity of beta-cyclodextrin derivatives: evidence for the role of cholesterol extraction.

Several beta-cyclodextrin (beta-CD) derivatives have been synthesized recently to improve the physicochemical properties and inclusion capacities of the parent molecule, however, there is limited information available about their cytotoxic effects. In this study we investigated the cytotoxic and hemolytic properties of various beta-CDs in correlation with their cholesterol-solubilizing capacities to expose the mechanism of toxicity. MTT cell viability test, performed on Caco-2 cells showed significant differences between the cytotoxicity of beta-CD derivatives. Cell toxicity of methylated-beta-CDs was the highest, while ionic derivatives proved to be less toxic than methylated ones. Most of the second generation beta-CD derivatives, having both ionic and methyl substituents showed less cytotoxicity than the parent compounds both on Caco-2 cells and human erythrocytes. Inclusion of cholesterol into the ring of randomly methylated-beta-CD and heptakis(2,6-di-O-methyl)-beta-CD abolished the cell toxicity indicating the role of cholesterol extraction in cytotoxicity. These data demonstrate the correlation between the cytotoxic effect, hemolytic activity and the cholesterol complexation attributes of beta-CD derivatives and we propose that cholesterol-solubilizing properties can be a predictive factor for beta-CD cell toxicity.

Cytotoxicity of different types of methylated beta-cyclodextrins and ionic derivatives.

Cyclodextrins (CDs) are widely used materials and still in the focus of drug development. In spite of the extensive studies, there is limited information about the cytotoxic effect of different derivatives. This study compares the cytotoxic effect of methylated beta-CDs and some ionic derivatives. The methylated CDs involved in this study differ in the number and position of the methyl substituents. Heptakis(2,6-di-O-methyl)-beta-CD (DIMEB) with a degree of substitution (DS) of 14 has two methyl groups in all of the seven glucose subunits mostly at O-2 and O-6 position, each OH group is methylated in heptakis(2,3,6-tri-O-methyl)-beta-CD (TRIMEB) (DS = 21), and an unsystematic substitution is realized in randomly methylated beta-CD (RAMEB). DS is defined as the number of substituents per cyclodextrin ring. Using the above definition, the DS for RAMEB is 12.6. To see the effect of the ionic groups an anionic and a cationic CD derivative were also investigated: (2-hydroxy-3-N,N,N-trimethylamino)propyl beta-CD (QABCD) (DS = 2) and carboxymethylated beta-CD (CMBCD) (DS = 3,5). The in vitro cell toxicity decreases in the order of DIMEB > TRIMEB > or = RAMEB > QABCD > CMBCD. Ionic beta-CDs were less toxic than the methylated derivatives.