Influence of the Sodium Salt of 3α,7α-Dihydroxy-12-Oxo-5β-Cholanate on Antimicrobial Activity of Ampicillin In Vitro

Background: Multiple resistances to antibiotics are an emergent problem worldwide. Scientists intensively search for new substances with the antimicrobial potential or the mode to restore the activity of old-generation antibiotics. Ampicillin is the antibiotic with the expanded range of antimicrobial activity, but its use has decreased due to the poor absorption and highly developed resistance. In vivo studies showed that ampicillin has better absorption and bioavailability if combined with bile acid salts. The aim of this study was to examine antimicrobial effects of ampicillin alone and its combination with semisynthetic monoketocholic acid salt (MKH) in vitro.Materials, Methods & Results: In this study, commercial preparation of ampicillin and sodium salt of 3α,7α-dihydroxy-12oxo-5β-cholanate were used. Their effects were evaluated on Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium), obtained from urine specimens of dogs with clinically manifested cystitis. The first two investigated strains were ampicillin-sensitive, while E. faecium was resistant to ampicillin. Modified macrodilution method according to Clinical and Laboratory Standards Institute Guidelines (M7-A8) was performed. Bacterial suspension equivalent to 0.5 McFarland was prepared in saline, compared to the standard (Biomerieux) ad oculi. The density was checked spectrophotometrically at a wavelength of 625 nm and adjusted if necessary to the desired absorbance from 0.08 to 0.1. The resultant suspension was diluted 1:100 and inoculated in test tubes. Number of bacteria was counted on Petri plates using dilutions from 10-3 to 10-7 in order to obtain valid and countable plates. One hundred microliters of appropriate dilutions were aseptically plated in triplicate onto nutrient agar. Plates were incubated on 37°C for 72 h, under aerobic conditions. The number of colony forming units (CFU) was determined by direct counting. As a valid for enumeration, we took plates with 30 to 300 CFU. Percentage of killed bacteria for ampicillin was from 69.33-95.19% for E. coli, 87.1296.92% for E. faecalis and 7.20-33.30% for E. faecium. Ampicillin applied in the combination with MKH killed 99.99% to 100% of E. coli, 94.59% to 99.91% of E. faecalis and 31.73% to 64.76% of E. faecium. Mean percentage of killed bacteria for ampicillin was 81.93% for E. coli, 91.64% for E. faecalis, and 18.13% for E. faecium, while in combination with MKH percentage was 99.96% for E. coli, 98.23% for E. faecalis and 47.54% for E. faecium.Discussion: Results are presented as pharmacological minimal inhibitory concentration (MIC) values. Ampicillin was applied at the concentration higher than the therapeutic one, which could explain high MIC values for E. coli and E. faecalis. The combination of ampicillin with MKH showed the best improvement of antimicrobial effect on E. faecium (Δ = 29.41%), isolate that was resistant to ampicillin when applied alone. In all the investigated isolates, the combinations with MKH were more effective than ampicillin administered alone. It seems that MKH demonstrates a synergistic antimicrobial activity with ampicillin in vitro, which considerably decreases MIC values for all investigated isolates. These results implicate that MKH could restore the previous activity of ampicillin against some bacteria, which could be a significant benefit for clinical practice

Influence of immediate release tablet formulation on dissolution profile of paracetamol

Introduction: Paracetamol is analgesic and antipyretic, which is usually in the form of an immediate release tablet formulations. Therapeutic effects in terms of the speed and intensity of the analgesic effect is dependent on speed of liberation from formulation. Aim: The aim of this work was to determine and compare dissolution profiles of 4 paracetamol immediate release tablet formulations and to determine influence of excipients on kinetic of paracetamol dissolution. Materials and Methods: Dissolution profiles of paracetamol tablets were determined using method with paddles and phosphate buffer pH 6.8 as a medium. Release of paracetamol was followed 60 minutes (using 6 time points). Concentration of paracetamol was measured using UV/Vis spectrophotometric method (243 nm). Dissolution profiles were compared using model-independent method (difference factor and similarity factor), statistic method (ANOVA-based method and pair Student's T-test, p<0.05) and model dependent methods (to determinate the release kinetics of paracetamol). Results: All formulations in the first 45 minutes liberated more than 85 % of the labled content. Formulation D, which contained superdesintegrator, released 90% of the content in the first 5 minutes. Though based on values of difference and similarity factors formulations are, not significantly different, ANOVA-based method showed that formulation A and B, B and C, as well as formulation B and D do statistically differ in all 6 time points, meaning they have parallel profiles. The release of paracetamol from formulations A and D is best described by the first order kinetic model, while the release of formulations B and C by the logistic model. Conclusions: The release kinetic of paracetamol is mostly influenced by the type of superdisintegrants and lubricants. Formulation with superdisintegrant technology OptiZorb® demonstrated fastes release rate and thus it is expected to produce the fastest pharmacodynamic effect.

Hypoglycemic Effect of Herbicide 2,4-Dichlorophenoxyacetic Acid (2,4-D)

Herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), a synthetic auxin which promotes uncontrolled plant growth is widely used. The aim of our study was to investigate, using an experimental model, the effect of herbicide 2,4-D on liver function tests, enzyme a amylaseand glucose blood level. BALB/C mice were treated i.p. with the herbicide (30 mg/kg 2,4-D) for four consecutive days. Twenty-four hours after the last injection, the treated and the control animals were weighed and sacrificed for biochemical analysis: haematocrit,glucose blood level, serum activities of enzymes alanine minotransferase, aspartate aminotransferase, gamma glutamyl transferase, and a amylase, as well as liver reduced glutathione.Herbicide 2,4-D significantly decreased glucose blood level in mice. There were no changes in liver function tests or activity of enzyme a amylase. In this study on mice we confirmed the results obtained in the previous study, which showed a hypoglycemic effect of herbicide 2,4-D on agricultural workers. To elucidate the mechanism of this effect, a further research is needed

The influence of probiotics on the cervical malignancy diagnostics quality

Background/Aim. Probiotics help to provide an optimum balance in the intestines. Probiotics species competitive block toxic substances and growth of unwanted bacteria and yeast species while they compete for the space and food. Lactogyn® is the first oral probiotics on Serbian market dedicated to maintaining a normal vaginal flora. Lactogyn® contains two well studied probiotics strains - Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14. Both of them are considered as probiotic agents with therapeutic properties increase the population of beneficial lactobacillus organisms within the vagina. The aim of this study was to exam an influence of Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 on results of cervical smear cytological testing including detection of atypical cells, detection of false positive and false negative findings as well as on vaginal microflora content in patients with vaginal infection signs and symptoms. Methods. Totally 250 women with signs of vaginal infection were selected to participate in the study. The study group comprised 125 patients taking studied probiotic strains along with specific anti-infective therapy. The control group comprised, also, 125 patients taking anti-infective agents, only. Probiotic preparation (Lactogyn ® capsules) was administered orally (one capsule daily) during 4 weeks. Before and six weeks after beginning of the therapy a cervical smear cytological test (the Papanicolaou test), as well as microbiological examination of the vaginal smear were performed. Results. Number of cases of inflammation and atypical squamous cells of undeterminated significance (ASCUS) in the study group were significantly higher before administration of the probiotic preparation. The number of lactobacilli was significantly higher, and the number of pathogenic microorganisms lower in the group treated with this preparation. Conclusion. The application of probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 concomitantly with specific antiinfective agents provides more reliable cytological diagnostics, reduces the number of false positive and false negative findings on cervical malignancy and normalizes vaginal microflora in higher percentage of patients with vaginal infections comapred with therapy including anti-infective agents only

Influence of Bile Acids in Hydrogel Pharmaceutical Formulations on Dissolution Rate and Permeation of Clindamycin Hydrochloride

Clindamycin hydrochloride is a widely used antibiotic for topical use, but its main disadvantage is poor skin penetration. Therefore, new approaches in the development of clindamycin topical formulations are of great importance. We aimed to investigate the effects of the type of gelling agent (carbomer and sodium carmellose), and the type and concentration of bile acids as penetration enhancers (0.1% and 0.5% of cholic and deoxycholic acid), on clindamycin release rate and permeation in a cellulose membrane in vitro model. Eight clindamycin hydrogel formulations were prepared using a 23 full factorial design, and they were evaluated for physical appearance, pH, drug content, drug release, and permeability parameters. Although formulations with carbomer as the gelling agent exerted optimal sensory properties, carmellose sodium hydrogels had significantly higher release rates and permeation of clindamycin hydrochloride. The bile acid enhancement factors were higher in carbomer gels, and cholic acid exerted more pronounced permeation-enhancing effects. Since the differences in the permeation parameters of hydrogels containing cholic acid in different concentrations were insignificant, its addition in a lower concentration is more favorable. The hydrogel containing carmellose sodium as a gelling agent and 0.1% cholic acid as a penetration enhancer can be considered as the formulation of choice

Interaction Between Different Extracts of Hypericum perforatum L. from Serbia and Pentobarbital, Diazepam and Paracetamol

Herb-drug interactions are an important safety concern and this study was conducted regarding the interaction between the natural top-selling antidepressant remedy Hypericum perforatum (Hypericaceae) and conventional drugs. This study examined the influence of acute pretreatment with different extracts of Hypericum perforatum from Serbia on pentobarbital-induced sleeping time, impairment of motor coordination caused by diazepam and paracetamol pharmacokinetics in mice. Ethanolic extract, aqueous extract, infusion, tablet and capsule of Hypericum perforatum were used in this experiment. The profile of Hypericum perforatum extracts as well as paracetamol plasma concentration was determined using RP-HPLC analysis. By quantitative HPLC analysis of active principles, it has been proven that Hypericum perforatum ethanolic extract has the largest content of naphtodianthrones: hypericin (57.77 µg/mL) and pseudohypericin (155.38 µg/mL). Pretreatment with ethanolic extract of Hypericum perforatum potentiated the hypnotic effect of pentobarbital and impairment of motor coordination caused by diazepam to the greatest extent and also increased paracetamol plasma concentration in comparison to the control group. These results were in correlation with naphtodianthrone concentrations. The obtained results have shown a considerable influence of Hypericum perforatum on pentobarbital and diazepam pharmacodynamics and paracetamol pharmacokinetics

Influence of the Sodium Salt of 3α,7α-Dihydroxy-12-Oxo-5β-Cholanate on Antimicrobial Activity of Ampicillin In Vitro

Background: Multiple resistances to antibiotics are an emergent problem worldwide. Scientists intensively search for new substances with the antimicrobial potential or the mode to restore the activity of old-generation antibiotics. Ampicillin is the antibiotic with the expanded range of antimicrobial activity, but its use has decreased due to the poor absorption and highly developed resistance. In vivo studies showed that ampicillin has better absorption and bioavailability if combined with bile acid salts. The aim of this study was to examine antimicrobial effects of ampicillin alone and its combination with semisynthetic monoketocholic acid salt (MKH) in vitro.Materials, Methods & Results: In this study, commercial preparation of ampicillin and sodium salt of 3α,7α-dihydroxy-12oxo-5β-cholanate were used. Their effects were evaluated on Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium), obtained from urine specimens of dogs with clinically manifested cystitis. The first two investigated strains were ampicillin-sensitive, while E. faecium was resistant to ampicillin. Modified macrodilution method according to Clinical and Laboratory Standards Institute Guidelines (M7-A8) was performed. Bacterial suspension equivalent to 0.5 McFarland was prepared in saline, compared to the standard (Biomerieux) ad oculi. The density was checked spectrophotometrically at a wavelength of 625 nm and adjusted if necessary to the desired absorbance from 0.08 to 0.1. The resultant suspension was diluted 1:100 and inoculated in test tubes. Number of bacteria was counted on Petri plates using dilutions from 10-3 to 10-7 in order to obtain valid and countable plates. One hundred microliters of appropriate dilutions were aseptically plated in triplicate onto nutrient agar. Plates were incubated on 37°C for 72 h, under aerobic conditions. The number of colony forming units (CFU) was determined by direct counting. As a valid for enumeration, we took plates with 30 to 300 CFU. Percentage of killed bacteria for ampicillin was from 69.33-95.19% for E. coli, 87.1296.92% for E. faecalis and 7.20-33.30% for E. faecium. Ampicillin applied in the combination with MKH killed 99.99% to 100% of E. coli, 94.59% to 99.91% of E. faecalis and 31.73% to 64.76% of E. faecium. Mean percentage of killed bacteria for ampicillin was 81.93% for E. coli, 91.64% for E. faecalis, and 18.13% for E. faecium, while in combination with MKH percentage was 99.96% for E. coli, 98.23% for E. faecalis and 47.54% for E. faecium.Discussion: Results are presented as pharmacological minimal inhibitory concentration (MIC) values. Ampicillin was applied at the concentration higher than the therapeutic one, which could explain high MIC values for E. coli and E. faecalis. The combination of ampicillin with MKH showed the best improvement of antimicrobial effect on E. faecium (Δ = 29.41%), isolate that was resistant to ampicillin when applied alone. In all the investigated isolates, the combinations with MKH were more effective than ampicillin administered alone. It seems that MKH demonstrates a synergistic antimicrobial activity with ampicillin in vitro, which considerably decreases MIC values for all investigated isolates. These results implicate that MKH could restore the previous activity of ampicillin against some bacteria, which could be a significant benefit for clinical practice