Development of the method for the pharmaceutical availability testing of clotrimazole from multiphase semi-solid vaginal dosage forms

Introduction: The intravaginal drug administration enables treatment of the local and systemic diseases. The anatomy and physiology of a vagina provide several difficulties for drug technologists due to the small amount and continuous production of vaginal discharge, especially in the case of lipophilic drugs often characterized by insufficient solubility. The application of poorly soluble drug substances in the form of nanoemulsions improves their availability. However, in the case of nanoemulsion-based vaginal dosage forms, no standardized methods have been defined for testing the amount of a drug released from encapsulated form. Aim of the study: Comparison and development of a method for testing the availability of active pharmaceutical substances from vaginal nanoemulsion-based drug forms. Materials and methods: The nanoemulsion and reference products (cream and suspension) were placed in a dialysis bag separating them from the acceptor medium. The changes in the concentration of the free fraction of the model active substance – clotrimazole were assessed. The experiments were performed using 2 static methods of different mixing method (magnetic stirring and USP apparatus III) and 2 dynamic methods including the flow of the medium through the flow-through cell at 2 mL/min and 2 mL/h. The experiments were conducted for 5 h. Results: Incomplete release of the active pharmaceutical ingredient was observed for all tested formulations over the experiment. Despite the delivery of a fresh portion of the medium, low concentrations of the free clotrimazole fraction were observed for both flow-through methods i.e., a maximum of about 7.5% of the dose for the 2 mL/min flow rate and 5% for the 2 mL/h flow rate. In stationary methods, the maximum recorded concentrations of the free fraction of the drug corresponded to approx. 25% of the initial amount. For the pilot stationary method, high standard deviations (SD) were observed, which affected the low discriminatory properties of the method. The method based on the reciprocating cylinder dissolution apparatus provided results exhibiting smaller SD and more significant differences between the tested formulations. The highest concentrations among the evaluated formulations were observed for nanoemulsion or nanoemulsion and suspension, depending on the used test technique. Significantly lower doses of the drug were released from the cream in almost every test. Conclusions: The selection of the method used to assess the pharmaceutical availability of an active pharmaceutical ingredient has a crucial impact on the release profiles obtained. The stationary method using a reciprocating cylinder apparatus (USP apparatus III) had the highest measurement precision and provided the most discriminatory results

New Insight into Genotypic and Phenotypic Relatedness of Staphylococcus aureus Strains from Human Infections or Animal Reservoirs

Cilj ovog rada bio je ispitati učinkovitost ekstrakcije bioaktivnih spojeva iz listova koprive (Urtica dioica L.) primjenom ubrzane ekstrakcije otapalima pri povišenom tlaku (ASE). Uz etanol kao ekstrakcijsko otapalo, ispitivani su sljedeći parametri ekstrakcije: (i) statičko vrijeme ekstrakcije (5 i 10 min); (ii) broj ciklusa ekstrakcije (1, 2, 3 i 4 ciklusa); te (iii) temperatura (20 i 50 °C). U dobivenim ekstraktima provedeno je spektrofotometrijsko određivanje ukupnih fenola, karotenoida te klorofila a i b. Rezultati istraživanja su pokazali kako sva tri varirana parametra značano utječu na masene udjele ispitivanih spojeva (p ≤ 0,01). Maseni udjeli ukupnih fenola određeni su u rasponu 106,44 do 739,72 mg 100 g-1, klorofila a od 116,44 do 490,42 mg 100 g-1, klorofila b od 44,88 do 166,85 mg g-1 te karotenoida od 36,62 do 133,99 mg 100 g-1. Najveći prinosi dobiveni su pri sljedećim uvjetima ekstrakcije: ukupni fenoli, karotenoidi i klorofil a pri temperaturi 50 °C i 4 ekstrakcijska ciklusa od 10 min; klorofil b pri temperaturi ekstrakcije od 50 °C, 3 ekstrakcijska ciklusa od 10 min.The aim of this study was to investigate the extraction efficiency of the bioactive compounds from stinging nettle (Urtica dioica L.) leaves by using Accelerated Solvent Extraction (ASE). Ethanol was used as the extraction solvent and the following extraction parameters were investigated: (i) static extraction time (5 and 10 min); (ii) number of extraction cycles (1, 2, 3 and 4 cycles); and (iii) temperature (20 and 50 °C). All extracts were spectrophotometrically evaluated in terms of total phenols, carotenoids and chlorophylls a and b. The results of the research have shown that all extraction parameters significantly affected the concetrations of the investigated compounds (p≤0,01). Mass fractions of total phenols ranged from 106,44 to 739,72 mg GAE 100 g-1, chlorophyll a from 116,44 to 490,42 mg 100 g-1, chlorophyll b from 44,88 to 166,85 mg 100 g-1 and carotenoids from 36,62 to 133,99 mg 100 g-1. The highest yields were obtained under the following extraction conditions: extraction temperature of 50 °C and four 10 minute cycles for total phenols, carotenoids and chlorophyll a and extraction temperature of 50 °C and three 10 minutes cycles for chlorophyll b

Analiza występowania wybranych czynników patogenności koagulazododatnich gronkowców pochodzących ze zmian chorobowych i od nosicieli, z uwzględnieniem Staphylococcus aureus fagotypu 187 /

zawiera wykaz prac będących przedmiotem rozprawy

On the characterization of concrete surface roughness and its relation to adhesion in repair systems

peer reviewedThe aim of this work is the analysis of an effect of concrete surface geometry on adhesion of repair systems. Several types of surface preparation techniques are selected and analysed via different systems: laser profilometry, mechanical profilometry, microscopy and "sand" patch test method

Probiotics: Should All Patients Take Them?

The usefulness of probiotics in the treatment as well as prevention of many infections and disorders has been confirmed by previous clinical studies. They can protect not only against gastrointestinal diseases such as diarrhea or enteritis but they have proven efficacy against pneumonia, urogenital infection, depression/anxiety, cancer metastasis, obesity, and others. However, it should be mentioned that not all clinical trials have shown improvement of health in patients undergoing probiotic treatment, and very rarely have even reported that probiotic strains may be the causative agents of opportunistic infections. Studies have documented cases of sepsis/bacteremia, endocarditis, liver abscess, pneumonia, and fungemia caused by probiotic strains, mainly in high-risk groups. This review summarizes the cases of infections caused by probiotic strains and the potential hazard associated with the supplementation of probiotics in seriously ill and hospitalized patients

Distribution and antibiotic-resistance of different Staphylococcus species identified by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) isolated from the oral cavity

Background: The use of antibiotics in dentistry is associated with the emergence and spread of antibiotic-resistant microorganisms, including commensal staphylococci. Methods: A total of 367 oral samples were collected, from which staphylococci were isolated and identified by using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF). The antibiotic susceptibility of the isolates was determined and molecular characteristics for methicillin-resistant staphylococci was performed. Results: A total of 103 coagulase-negative staphylococci (CoNS), among them S. warneri, S. haemolyticus, S. saprophyticus, S. pasteuri, S. epidermidis, S. hominis, S. xylosus, S. equorum, S. kloosii, S. succinus, S. cohnii, and S. simulans, were confirmed by MALDI-TOF. Resistance to most tested antibiotics was statistically higher in CoNS than in S. aureus isolates (P-value < 0.05). CoNS isolates showed high resistance to penicillin (S. saprophyticus 88.9%), erythromycin (S. haemolyticus 84.6%), fusidic acid (S. saprophyticus 77.8%), co-trimoxazole (S. epidermidis 71.4%), gentamicin (S. warneri 63.8%), and tetracycline (S. saprophyticus 55.6%). Multidrug resistance was largely observed, especially among S. haemolyticus and S. saprophyticus species. Methicillin-resistance in S. haemolyticus (38.5%), S. saprophyticus (22.2%) and S. aureus (13.5%) was associated with the presence of the mecA gene and SCCmec type IV or V. Conclusion: Coagulase-negative staphylococci, especially S. haemolyticus and S. saprophyticus, seem to be a reservoir of methicillin resistance and multidrug resistance in the oral cavity

Protein Hydrolysates Derived from Animals and Plants&mdash;A Review of Production Methods and Antioxidant Activity

There is currently considerable interest on the use of animal, plant, and fungal sources in the production of bioactive peptides, as evidenced by the substantial body of research on the topic. Such sources provide cheap and environmentally friendly material as it often includes waste and by-products. Enzymatic hydrolysis is considered an efficient method of obtaining peptides capable of antioxidant activity. Those properties have been proven in terms of radical-scavenging capacity using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2-azinobis-(3-ethyl-benzothiazoline-6-sulphonic acid)), hydroxyl and superoxide radical methods. Additionally, the reducing power, ferrous ion-chelating (FIC), ferric reducing antioxidant power (FRAP), and the ability of the protein hydrolysates to inhibit lipid peroxidation have also been explored. The results collected in this review clearly indicate that the substrate properties, as well as the conditions under which the hydrolysis reaction is carried out, affect the final antioxidant potential of the obtained peptides. This is mainly due to the structural properties of the obtained compounds such as size or amino acid sequences

Do the oral Staphylococcus aureus strains from denture wearers have a greater pathogenicity potential?

We used flow cytometry to compare the phagocytic activity of monocytes against Staphylococcus aureus strains (both biofilm and planktonic cells) isolated from denture wearers and non-wearers. Staphylococcal strains were cultured in Brain Heart Infusion broth in both planktonic and biofilm form and were stained with a fluorescent reporter (propidium iodide) and incubated with monocytes. The fluorescence of the monocytes containing phagocytized bacteria was determined by flow cytometry and normalized to that of the bacterial strains used in the experiment. Staphylococcal strains from denture wearers caused greater activation of monocytes but were less prone to phagocytosis. The percentage of monocytes containing bacterial cells after exposition to staphylococcal strains varied from 2.7% to 81.4% for planktonic cells. For biofilm-released cells, this value ranged from 0.6% to 36.2%. The effectiveness of phagocytosis, estimated based on an increase in monocyte fluorescence, amounted to 32.4 and 71 FL2 units for the biofilm and planktonic cells, respectively. The lesser efficiency of phagocytosis against biofilm S. aureus in denture wearers suggests that they might have been colonized with the strains which were less prone to eradication than those from non-wearers