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Journal of Nanoscience and... Jan 2013This work was aimed to develop reusable magnetite chitosan composite containing carbon paste electrode for biosensor application. Glucose oxidase (GOx) enzyme was used...
This work was aimed to develop reusable magnetite chitosan composite containing carbon paste electrode for biosensor application. Glucose oxidase (GOx) enzyme was used to prepare GOx-magnetite-chitosan nanocomposite containing carbon paste electrode for sensitive detection of glucose. The immobilized enzyme retained its bioactivity, exhibited a surface confined reversible electron transfer reaction, and had good stability. The surface parameters like surface coverage (tau), Diffusion coefficient (D0), and rate constant (kS) were studied. The carbon paste modified electrode virtually eliminated the interference during the detection of glucose. The excellent performance of the biosensor is attributed to large surface-to-volume ratio, high conductivity and good biocompatibility of chitosan, which enhances the enzyme absorption and promotes electron transfer between redox enzymes and the surface of electrode. The shelf life of the developed electrode system is about 12 weeks under refrigerated conditions. We report for the first time in the fabrication of carbon paste bioelectrode containing magnetite-chitosan-GOx.
Topics: Biosensing Techniques; Carbon; Chitosan; Conductometry; Electrodes; Equipment Design; Equipment Failure Analysis; Glucose; Glucose Oxidase; Magnetite Nanoparticles; Ointments
PubMed: 23646703
DOI: 10.1166/jnn.2013.6720 -
Biosensors & Bioelectronics 1994Highly sensitive biosensors for phenolic compounds, based on the incorporation of the enzyme tyrosinase within metal-dispersed carbon paste matrices are described. In...
Highly sensitive biosensors for phenolic compounds, based on the incorporation of the enzyme tyrosinase within metal-dispersed carbon paste matrices are described. In particular, ruthenium-doped carbon pastes display excellent electrocatalytic activity for the reduction of the enzymatically generated quinone species. Hence, convenient quantitation of micromolar concentrations is feasible at 0.0 V (vs. Ag/AgCl reference), with a greatly enhanced response compared to conventional carbon-paste tyrosinase biosensors. The influence of various experimental variables is explored. Fast, sensitive and reproducible flow injection detection of phenolic compounds is illustrated. Analogous improvements are reported for tyrosinase-rich plant tissue electrodes.
Topics: Biosensing Techniques; Carbon; Catalysis; Monophenol Monooxygenase; Ointments; Phenols; Ruthenium
PubMed: 8166960
DOI: 10.1016/0956-5663(94)80009-x -
Natural Product Research Sep 2016Perna canaliculus is a nutritional supplement recently studied and highly recommended for its anti-inflammatory effects in both animals and humans. In this study, the...
Perna canaliculus is a nutritional supplement recently studied and highly recommended for its anti-inflammatory effects in both animals and humans. In this study, the physicochemical properties, the microbiological quality, the total lipid content and fatty acids composition of three commercial samples of Perna powder were determined. Subsequently, three simple formulations of extemporaneous oral pastes containing Perna were prepared and designed for veterinary use. Their microbiological stability was assessed after 1-month storage at either room temperature or 35 °C. The results demonstrated that commercial Perna samples lack homogeneity, in regard to some technological properties and fatty acid composition; therefore, a preliminary characterisation of commercial Perna samples is recommended to assure the quality of formulations containing this nutritional supplement. Oral paste formulations are easy and simple to prepare and show good physical and microbiological stability, suggesting their large-scale production.
Topics: Animals; Dietary Supplements; Drug Compounding; Drug Stability; Fatty Acids; Fatty Acids, Nonesterified; Gas Chromatography-Mass Spectrometry; Lipids; Ointments; Perna; Temperature; Veterinary Drugs
PubMed: 26592902
DOI: 10.1080/14786419.2015.1107557 -
International Journal of Pharmaceutical... 2014This article represents the third in a series of articles on tips and hints ofcompounding. In this issue, we will discuss some tips and hints for the compounding of... (Review)
Review
This article represents the third in a series of articles on tips and hints ofcompounding. In this issue, we will discuss some tips and hints for the compounding of ointments, creams, pastes, gels, and gel-creams. For clarification, a gel-cream is a cream in which the external aqueous phase has been thickened using a gelling agent; the advantage is a more stable cream.
Topics: Administration, Topical; Drug Carriers; Drug Compounding; Excipients; Gels; Humans; Ointments; Pharmaceutical Preparations
PubMed: 25306771
DOI: No ID Found -
Biosensors & Bioelectronics Apr 2009The electrocatalytic oxidation of acetylcholine (Ach) on two different copper-based transducers, copper microparticles-modified carbon paste electrode (m-CPE) and copper...
The electrocatalytic oxidation of acetylcholine (Ach) on two different copper-based transducers, copper microparticles-modified carbon paste electrode (m-CPE) and copper nanoparticles-modified carbon paste electrode (n-CPE), was investigated. In the voltammograms recorded using m-CPE, a single anodic oxidation peak related to the oxidation of ACh was appeared which was related to the electrocatalytic oxidation of ACh via the electrogenerated Cu(III) species in an EC' mechanism. Using n-CPE, however, two overlapped anodic peaks appeared which were related to two fine tunable steps of oxidation. ACh oxidized on n-CPE with higher rates at low potentials with respect to m-CPE. The kinetic of the reaction was formulated and the charge-transfer resistance of the system was obtained both theoretically and experimentally. The catalytic rate constant, the transfer coefficient for the electrocatalytic oxidation and the diffusion coefficients for ACh were reported using chronoamperometry, pseudo-steady-state polarization measurement and electrochemical impedance spectroscopy. Sensitive and time-saving sensing procedures in both batch and flow systems were developed for the analysis of ACh, and the corresponding analytical parameters were reported.
Topics: Acetylcholine; Biosensing Techniques; Copper; Electrochemistry; Electrodes; Equipment Design; Equipment Failure Analysis; Nanoparticles; Ointments; Reproducibility of Results; Sensitivity and Specificity; Transducers
PubMed: 19237275
DOI: 10.1016/j.bios.2008.10.036 -
Journal of Veterinary Medicine. A,... Dec 2004In this study, the efficacy of the non-antibiotic paste Protexin Hoof-Care containing metallic salts and organic acids, was tested for local treatment of 26 acute... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
In this study, the efficacy of the non-antibiotic paste Protexin Hoof-Care containing metallic salts and organic acids, was tested for local treatment of 26 acute digital dermatitis lesions. The control group (26 cases) was treated with local application of oxytetracycline spray. These 52 affected limbs with digital dermatitis were diagnosed in 47 dairy cows from eight different farms with slatted floors. The therapeutic effect was evaluated using a scoring system for weightbearing at stance, lameness at walk and pain of the digital dermatitis lesions. The pre-treatment and control examination scores were documented on days 0, 4, 10 and 28. Both treatment regimens were effective, no statistical differences regarding the examined parameters was found between the group treated with the non-antibiotic Protexin Hoof-Care paste and the group treated with oxytetracycline spray. Twenty-seven digital dermatitis lesions required only one treatment with one of these products. A second topical treatment was carried out on day 4 in 13 lesions of the study group and in 12 lesions of the control group. The data of this pilot study indicate that the non-antibiotic paste Protexin Hoof-Care could be a valuable alternative to topical antibiotic treatment for digital dermatitis in dairy cattle.
Topics: Administration, Topical; Animals; Anti-Infective Agents, Local; Cattle; Cattle Diseases; Dermatitis; Foot Dermatoses; Hoof and Claw; Ointments; Pilot Projects; Severity of Illness Index; Treatment Outcome
PubMed: 15610490
DOI: 10.1111/j.1439-0442.2004.00671.x -
Journal of Pharmaceutical and... Aug 1998A stability-indicating high-performance liquid-chromatographic (HPLC) assay has been developed for amphotericin B (AmB) in a paste, containing AmB, tobramycin (or...
A stability-indicating high-performance liquid-chromatographic (HPLC) assay has been developed for amphotericin B (AmB) in a paste, containing AmB, tobramycin (or gentamicin) sulphate, colistin sulphate, liquid paraffin and Orabase. Extraction of AmB was performed by partitioning the antibiotic between N,N-dimethylformamide (DMF) and cyclohexane, which led to precipitation of the polymeric materials and extraction of the liquid paraffin into the cyclohexane and AmB into the DMF. Analysis by HPLC of the latter layer gave a linear relationship between concentration and peak area response for the AmB over the range 5.0 x 10(-4) to 7.5 x 10(-3)% (w/v) (r = 0.9995) with a relative standard deviation of +/- 1.46% (n = 8). The efficiency of extraction was 1006 +/- 2.4% (n = 5).
Topics: Amphotericin B; Antifungal Agents; Chromatography, High Pressure Liquid; Colloids; Ointments
PubMed: 9682159
DOI: 10.1016/s0731-7085(97)00250-1 -
Yakugaku Zasshi : Journal of the... 2019To clarify the volume of water required to paste pediatric powders, we herein established a standard for the powder paste state by measuring yield values when water was...
To clarify the volume of water required to paste pediatric powders, we herein established a standard for the powder paste state by measuring yield values when water was added to powders. The powders used in the present study were selected from 8 types including original and generic drugs. Tipepidine hibenzate is prescribed in the pediatric field in combination with ambroxol hydrochloride and l-carbocysteine. The volumes of water needed to achieve the paste state of ambroxol hydrochloride between the original and generic drugs were similar. However, the volumes of water needed for l-carbocysteine markedly differed between the original and generic drugs due to differences in their additives. The spreadability of the mixture when water was added to the powders was evaluated using a spread meter. Among the powders tested in the present study, the yield value to achieve a paste state with the addition of water was approximately 1000 dyne/cm. The optimum volume of water estimated from this yield value using the linear proportional relationship for the amount of powder may be applied to the mixture of each pediatric power for dosage/body weight.
Topics: Adjuvants, Pharmaceutic; Ambroxol; Carbocysteine; Drug Compounding; Drugs, Generic; Ointments; Piperidines; Powders; Water
PubMed: 30713242
DOI: 10.1248/yakushi.18-00182 -
Archives of Oral Biology Oct 2016We investigated the residual antibiofilm effects of different concentrations of double antibiotic paste (DAP) applied on radicular dentin for 1 or 4 weeks.
OBJECTIVE
We investigated the residual antibiofilm effects of different concentrations of double antibiotic paste (DAP) applied on radicular dentin for 1 or 4 weeks.
DESIGN
Dentin samples were prepared (n=120), sterilized and pretreated for 1 or 4 weeks with the clinically used concentration of DAP (500mg/mL), low concentrations of DAP (1, 5 or 50mg/mL) loaded into a methylcellulose system, calcium hydroxide (Ca(OH)), or placebo paste. After the assigned treatment time, treatment pastes were rinsed off and the samples were kept independently in phosphate buffered saline for 3 weeks. Pretreated dentin samples were then inoculated with Enterococcus faecalis and bacterial biofilms were allowed to grow for an additional 3 weeks. Biofilms were then retrieved from dentin using biofilm disruption assays, diluted, spiral plated, and quantified. Fisher's Exact and Wilcoxon rank sum tests were used for statistical comparisons (α=0.05).
RESULTS
Dentin pretreatment for 4 weeks with 5, 50 or 500mg/mL of DAP demonstrated significantly higher residual antibiofilm effects and complete eradication of E. faecalis biofilms in comparison to a 1 week pretreatment with similar concentrations. However, dentin pretreated with 1mg/mL of DAP or Ca(OH) did not provide a substantial residual antibiofilm effect regardless of the application time.
CONCLUSIONS
Dentin pretreatment with 5mg/mL of DAP or higher for 4 weeks induced significantly higher residual antibiofilm effects in comparison to a 1 week pretreatment with the same concentrations.
Topics: Anti-Bacterial Agents; Bacterial Load; Biofilms; Dentin; Endodontics; Enterococcus faecalis; Humans; Microbial Sensitivity Tests; Ointments; Random Allocation; Regeneration; Root Canal Irrigants; Tooth Root
PubMed: 27341460
DOI: 10.1016/j.archoralbio.2016.06.006 -
Journal of Materials Science. Materials... Feb 2015The use of hydraulic calcium phosphate cements (CPCs) as bone substitute is impaired by their relatively poor handling due to the need to mix a powder and a liquid...
The use of hydraulic calcium phosphate cements (CPCs) as bone substitute is impaired by their relatively poor handling due to the need to mix a powder and a liquid during surgery. The aim of the present study was to assess the possibility to design CPCs as inorganic dual-paste cements, where both pastes would be stable for years, but would react as soon as they are mixed together. Results showed that aqueous pastes of α-tricalcium phosphate (α-TCP) powder could be stabilized for up to a year at room temperature by the use of 0.1 M Mg chloride solution. Adding a calcium chloride solution in a 1:4 volume ratio activated α-TCP pastes provided the Ca/Mg ratio was larger than one. Mechanistic investigations suggest that Ca ions can displace Mg cations adsorbed at the surface of α-TCP particles to initiate α-TCP transformation to calcium-deficient hydroxyapatite and concomitant paste hardening. The compressive strength (29 MPa) was similar to that of commercial formulations (5-80 MPa). Other divalent cations (Ba, Ni, Sr) had a similar effect although with a different degree of efficacy.
Topics: Adhesiveness; Bone Cements; Calcium Phosphates; Cations; Compressive Strength; Drug Design; Drug Stability; Hardness; Inorganic Chemicals; Materials Testing; Ointments; Powders
PubMed: 25631266
DOI: 10.1007/s10856-015-5400-z