Chloramphenicol Solution Research Articles

Amperometric aptasensing of chloramphenicol at a glassy carbon electrode modified with a nanocomposite consisting of graphene and silver nanoparticles

A nanocomposite prepared from reduced graphene oxide (rGO) and silver nanoparticles (AgNPs) is used in an electrochemical aptasensor for the sensitive and selective determination of the antibiotic chloramphenicol (CAP). The nanocomposite was obtained by electrostatic assembly of AgNPs on the surface of polyelectrolyte-functionalized rGO and then used to modify a glassy carbon electrode. The biosensor is then obtained by immobilizing the aptamer against CAP. When incubated with solutions of CAP, the sensor surface is loaded with CAP due to aptamer recognition. The captured CAP can be electrochemically reduced to yield a current that is strongly enhanced as a result of the excellent electrocatalysis property of the graphene/AgNP-nanocomposite. Under optimum conditions, the calibration plot is linear in the 0.01 to 35 μM concentration range, with a 2 nM detection limit (at 3σ). The sensor is reproducible, stable, selective over homologous interferents, and performs excellently when analyzing CAP in milk samples.

Contribution of persulfate in UV-254 nm activated systems for complete degradation of chloramphenicol antibiotic in water

In this work, we investigated the treatment of chloramphenicol (CAP) solution using a persulfate (PS)-based Advanced Oxidation Process (AOP) generating sulfate and hydroxyl radicals upon exposure to low intensity UV. Experiments were carried out at 20°C in photo-reactors equipped with 4.9 Watt Low Pressure Mercury Lamp (LPHgL). Several experimental parameters were varied and evaluated to optimize the degradation process reaching therefore better mineralization of CAP and its degradation products. Parameters included: UV power, PS concentration, pH, dissolved ions e.g. HCO3−, Cl−, SO42−, nutrients e.g. NO3−, NO2−, HPO42− and organic acids e.g. fumaric acid, humic acids. Results showed that: (i) CAP degradation followed pseudo-first order kinetics with an optimized t1/2 lesser than 5min under controlled conditions; (ii) CAP mineralization extent was proportional to the amount of PS used (0.25–5.0mM) with no mineralization noticed in the absence of PS; (iii) The calculated % reaction stoichiometric efficiency (RSE) reached values up to 52% comparable to that of RSE obtained in thermally activated PS systems, however, exceeding by far RSE values in chemically activated systems; (iv) PS can be sustained in solution at high % RSE upon sequential CAP addition; (v) CAP partially disappeared along with coliforms in CAP-spiked non-treated wastewater samples using UV/PS system under moderate conditions; (vi) The optimized AOP showed an experimental break-even point between mineralization and CAP degradation at [PS]=0.5mM and a fluence of 330J for 1h reaction. CAP transformation products were identified by HPLC/MS and a CAP primary degradation reaction pathway was proposed. This study demonstrated that UV/PS system is much stronger than UV-only system for rapid and complete mineralization of CAP in water.

The In Vitro Antimicrobial Effects of Lavandula angustifolia Essential Oil in Combination with Conventional Antimicrobial Agents.

The paper focuses on the in vitro antimicrobial activity of Lavandula angustifolia Mill. (lavender) essential oil in combination with four commercial antimicrobial agents. Stock solutions of chloramphenicol, ciprofloxacin, nystatin, and fusidic acid were tested in combination with L. angustifolia essential oil. The antimicrobial activities of the combinations were investigated against the Gram-positive bacterial strain Staphylococcus aureus (ATCC 6538) and Gram-negative Pseudomonas aeruginosa (ATCC 27858) and Candida albicans (ATCC 10231) was selected to represent the yeasts. The antimicrobial effect was performed using the minimum inhibitory concentration (MIC) microdilution assay. Isobolograms were constructed for varying ratios. The most prominent interaction was noted when L. angustifolia essential oil was combined with chloramphenicol and tested against the pathogen P. aeruginosa (ΣFIC of 0.29). Lavendula angustifolia essential oil was shown in most cases to interact synergistically with conventional antimicrobials when combined in ratios where higher volumes of L. angustifolia essential oil were incorporated into the combination.

Degradation and reorganization of thylakoid protein complexes ofBryum argenteumin response to dehydration and rehydration

We analyzed the desert moss Bryum argenteum Hedw., a dominant moss in biological soil crusts in northwestern China, during dehydration and rehydration. There was almost no change in chlorophyll content between hydrated and almost completely desiccated B. argenteum samples. The amounts of thylakoid protein complexes, including the PSI monomer, PSII supercomplex, the PSII monomer, and LHCII, gradually decreased as the dehydration time of B. argenteum was extended. Analysis by two-dimensional sodium dodecylsulfate-urea- polyacrylamide gel electrophoresis showed that the amount of the PSII core subunits CP47 and CP43 and the PSI core subunits PsaA/B decreased during dehydration. The amount of thylakoid protein complexes increased rapidly during rehydration under light conditions, but increased slowly, and to lower levels, during rehydration in the dark. Rehydration of B. argenteum in chloramphenicol solution under light conditions resulted in a decrease in FV/FM within 10 min. An analysis of chloroplast ultrastructure showed that the number of grana decreased during dehydration. Taken together, our results suggest that the thylakoid protein complexes of B. argenteum degrade during dehydration and then reassemble during rehydration, and that this affects the full recovery of photosynthesis in this species.

The Effect of Commonly Used Surgical Solutions on the Tensile Strength of Sutures

To investigate the new practice of soaking sutures prior to use in strabismus surgery in an effort to avoid endophthalmitis. Specimens of 6-0 polyglactin suture were loaded in tension until failure occurred. Tests performed were without modification and after soaking in normal saline solution, 5% povidone-iodine solution, and 0.5% chloramphenicol solution for 30 minutes. There was no significant difference between the four groups with regard to mean force or type of solution used. Soaking polyglactin sutures in various solutions used in strabismus surgery for 30 minutes had no effect on the tensile strength.

Investigation on the Bacterial Haemorrhagic Septicemia Disease of Cyprinus carpio and Channa striatus

Bacterial Hemorrhagic Septicemia (BHS) was found affecting Cyprinus carpio and Channa striatus. Bacteriological examination and artificial infection trials were carried out on these fishes. Hematological examination showed substantial decline in the number of erythrocytes and lymphocytes, increase in the number of granulocytes and significant loss in the amount of hemoglobin. Histopathological examination suggested that the affected part of the skin had got completely destroyed. The peripheral area of the liver showed loosening of tissue and cell distension. There was complete shrinkage in all the components of kidney and glomeruli appeared smaller in size than healthy ones. Artificially infected specimens of C. carpio and C. striatus were treated with 20 ppm and 30 ppm chloramphenicol solution and oxytetracycline @ 50 and 60 mg/kg of feed for 20 and 30 days respectively. The results of this work indicated that Aeromonas hydrophila and Pseudomonas fluorescens were the etiological agents for this disease.

Mineralization of the antibiotic chloramphenicol by solar photoelectro-Fenton: From stirred tank reactor to solar pre-pilot plant

Chloramphenicol is a widely used broad-spectrum antibiotic, which has been detected as emerging pollutant in natural waters. The mineralization of this drug in a synthetic sulfate solution of pH 3.0 has been studied by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF), UVA photoelectro-Fenton (PEF) and solar photoelectro-Fenton (SPEF). Comparative electrolyses carried out with 100mL stirred tank reactors equipped with a boron-doped diamond (BDD) or Pt anode and an air-diffusion cathode at constant current density showed the superiority of the processes with BDD because of the higher oxidation ability of •OH formed from water oxidation at the BDD surface. Total mineralization was rapidly reached for the most potent treatment of SPEF with BDD due to the additional oxidation by •OH produced from Fenton's reaction between added Fe2+ (0.5mM) and H2O2 generated at the cathode, together the synergistic photolytic action of sunlight, much more intense than the 6W UVA lamp used in PEF. Chloramphenicol decay always followed a pseudo-first-order kinetics. The influence of current density and substrate concentration on SPEF with BDD was examined. Nine aromatic products, thirteen hydroxylated derivatives and seven carboxylic acids were identified by different chromatographic techniques. While the initial Cl of the drug was released as chloride ion, its initial N was lost as nitrate ion and, in smaller proportion, as ammonium ion. From the detected products, a general reaction pathway for chloramphenicol mineralization is proposed. The viability of SPEF was confirmed in a 10L pre-pilot plant with a Pt/air-diffusion filter-press reactor coupled to a solar CPCs photoreactor. After 180min of electrolysis at 100mAcm−2, a 245mgL−1 chloramphenicol solution in 0.05M Na2SO4 with 0.5mM Fe2+ at pH 3.0 underwent 89% mineralization with 36% current efficiency and 30.8kWhm−3 energy cost.

Occurrence of Chloramphenicol in Crops through Natural Production by Bacteria in Soil

Due to the unexpected findings of the banned antibiotic chloramphenicol in products of animal origin, feed, and straw, the hypothesis was studied that the drug is naturally present in soil, through production by soil bacteria, and subsequently can be transferred to crops. First, the stability of chloramphenicol in soil was studied. The fate of chloramphenicol highly depends on soil type and showed a half-life of approximately one day in nonsterile topsoil. It was found to be more stable in subsoil and sterile soils. Second, the production of chloramphenicol in soil was studied, and it was confirmed that Streptomyces venezuelae can produce chloramphenicol at appreciable amounts in nonsterile soil. Third, a transfer study was carried out using wheat and maize grown on three different soils that were weekly exposed to aqueous chloramphenicol solutions at different levels. Chloramphenicol was taken up by crops as determined by chiral liquid chromatography coupled to tandem mass spectrometric analysis, and the levels in crops were found to be bioavailability related. It was concluded that chloramphenicol residues can occur naturally in crops as a result of the production of chloramphenicol by soil bacteria in their natural environment and subsequent uptake by crops.

Combining molecular imprinted nanoparticles with surface plasmon resonance nanosensor for chloramphenicol detection in honey

AbstractThe focus of this article is to develop a surface plasmon resonance (SPR) nanosensor to determine chloramphenicol (CAP) using the molecularly imprinted nanoparticles. The CAP imprinted nanoparticles were prepared by miniemulsion polymerization method. Then, the nanoparticles were attached onto the SPR nanosensor surface via temperature‐controlled evaporation. Surface characterization studies were performed with atomic force microscopy and contact angle measurements. Kinetic studies were performed with CAP solutions in the concentration range of 0.155–6.192 nM. Florphenicol (FLP) and thiamphenicol (TAP) having similar chemical structures to the template (i.e., CAP) were chosen as competitors to determine selectivity of the nanoparticles. Selectivity constants were observed as 8.86 for CAP/TAP and 8.36 for CAP/FLP. The detection limit was calculated as 40 ng/kg honey sample. In the light of these results, it was emphasized that the SPR nanosensor is able to recognize CAP selectively and has a potential for real‐time CAP detection in honey sample. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Use of Surface-enhanced Raman Spectroscopy for the Test of Residuals of Prohibited and Restricted Drugs in Fish Muscle

The objective of this study was to investigate the feasibility of applying surface-enhanced Raman spectroscopy (SERS) coupled with partial least squares regression (PLSR) to detect and determine prohibited or restricted residual fish drugs including malachite green, crystal violet, chloramphenicol and sulfamerazine. Standard solutions of malachite green (0.5~50 µg/L), crystal violet (5~100 µg/L), chloramphenicol (50~5.0×10 3 µg/L) and sulfamerazine (500~5.0×10 3 µg/L) were used to determine the sensibility of the SERS method as well as the accuracy of the PLSR models for quantitative analyses of the fish drugs. In addition, fish muscles artificially contaminated with malachite green (0.5~50 µg/kg) or crystal violet (10~100 µg/kg) were used for the study. Two different types of commercial gold-coated SERS substrates were used to acquire SERS spectra (400~2000 cm -1 ) of standard solutions or fish extracts. Then, laser source (633 and 780 nm) and laser power (5 and 10 mW) were varied for optimum results to collect spectra of different drugs. PLSR was applied for quantitative analysis of the tested fish drugs. The results indicated that SERS technology is a sensitive method for analyzing industrial dyes, which could detect malachite green and crystal violet at concentration levels as low as 0.8 and 10 µg/L, respectively. For chloramphenicol and sulfamerazine, the lowest concentrations could be detected were 50 and 500 µg/L, respectively. The PLSR models for four standard solutions yielded R 2 of 0.865 to 0.954. For malachite green and crystal violet extracts from fish, the lowest concentrations detected were 1.0 and 20 µg/kg, respectively, which indicated great potential of applying SERS in determination of residual prohibited or restricted fish drugs in food system. Keywords malachite green; crystal violet; chloramphenicol; sulfamerazine; surface-enhanced Raman spectroscopy; fish muscle

Antibacterial effects of Iranian native sour and sweet pomegranate (Punica granatum) peel extracts against various pathogenic bacteria

Summary Nowadays, uncontrolled and frequent use of antibiotics may cause emergence of microbial resistance among pathogenic agents. Therefore, the use of new synthetic and natural antimicrobial compounds is inevitable. One source of natural compounds in this respect comes from plants. The purpose of this study was to examine the antibacterial effects of peel extracts from sour and sweet pomegranate. Methanolic extracts of sour and sweet pomegranate peels and aqueous solutions of tetracycline and chloramphenicol were prepared. Antibiogram tests using disk diffusion technique and serial dilution method were performed against ten pathogenic bacteria isolated from animals, and relative minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were also determined for the above compounds. The greatest zone of inhibition induced by the action of pomegranate peel extracts was obtained for Staphylococcus aureus (about 25 mm) and the smallest zone of inhibition was obtained for Pasteurella multocida (about 9 mm). In addition, the lowest MIC and MBC values of pomegranate peel extract were obtained for Staphylococcus aureus (7.8 and 62.5 mg/ml, respectively). Results of serial dilution tests indicate that bactericidal effect of sour pomegranate peel extract was more than that for sweet pomegranate peel extract; and sweet pomegranate peel extract exerts a bacteriostatic action against bacteria. The antibacterial effect was greater against Gram-positive bacteria compared to that for the Gram-negative bacteria. Effects of these extracts were considerably lower than those for tetracycline and chloramphenicol. In conclusion, methanolic extracts of pomegranate peels exhibit relatively good bacteriostatic and bactericidal effects.

CHLORAMPHENICOL WITH FLUID AND ELECTROLYTE THERAPY CURES TERMINALLY ILL GREEN TREE FROGS (LITORIA CAERULEA) WITH CHYTRIDIOMYCOSIS

Terminal changes in frogs infected with the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd) include epidermal degeneration leading to inhibited epidermal electrolyte transport, systemic electrolyte disturbances, and asystolic cardiac arrest. There are few reports of successful treatment of chytridiomycosis and none that include curing amphibians with severe disease. Three terminally ill green tree frogs (Litoria caerulea) with heavy Bd infections were cured using a combination of continuous shallow immersion in 20 mg/L chloramphenicol solution for 14 days, parenteral isotonic electrolyte fluid therapy for 6 days, and increased ambient temperature to 28 degrees C for 14 days. All terminally ill frogs recovered rapidly to normal activity levels and appetite within 5 days of commencing treatment. In contrast, five untreated terminally ill L. caerulea with heavy Bd infections died within 24-48 hr of becoming moribund. Subclinical infections in 15 experimentally infected L. caerulea were cured within 28 days by continuous shallow immersion in 20 mg/L chloramphenicol solution without adverse effects. This is the first known report of a clinical treatment protocol for curing terminally ill Bd-infected frogs.

Radiation induced degradation of pharmaceutical residues in water: Chloramphenicol

The γ-radiolytic degradation of chloramphenicol (CPL) was investigated in 0.1–1mmoldm−3 aqueous solutions at various radiation conditions. The destruction of CPL was monitored by UV–vis spectrophotometric method through the decrease in the intensity of the absorbance band at 276nm. LC-MS/MS was used to identify the degradation products. Results indicate that •OH can add onto the CPL aromatic ring or can abstract H-atom from the side chain. The reductive dechlorination of CPL was also studied based on the reaction of eaq− with CPL. In 0.1mmoldm−3 solution above 2.5kGy dose complete CPL degradation was achieved. In the presence of dissolved oxygen at relatively low dose, various oxidation products were observed. In the presence of tertiary butanol radical scavenger tertiary butanol group containing products were also detected. The toxicity increased as a function of dose to 1.0kGy. At doses higher than 1.0kGy the toxicity decreased continuously due to further degradation. It was also demonstrated that the O2−•/HO2• pair has low reactivity in CPL solution.

Pre-Electrospray Ionisation Manifold Methylation and Post-Electrospray Ionisation Manifold Cleavage/Ion Cluster Formation Observed during Electrospray Ionisation of Chloramphenicol in Solutions of Methanol and Acetonitrile for Liquid Chromatography-Mass Spectrometry Employing a Commercial Quadrupole Ion Trap Mass Analyser

We have observed unusual mass spectra of chloramphenicol (CAP) in solutions of methanol or acetonitrile showing intense ions at m/z 297, m/z 311, m/z 325 and m/z 339. The observed ions were different from those which are traditionally observed in the full scan ESI mass spectra of CAP with ions of m/z 321, m/z 323 and m/z 325. We have evidence to show that this process starts with offline methylation of CAP in solutions of methanol or acetonitrile to give m/z 339. Investigations using nuclear magnetic resonance (NMR) spectroscopy showed that there is a methylene group somewhere within the CAP molecule but not attached to any of the carbon atoms when the CAP is dissolved in methanol or acetonitrile before infusion into the mass spectrometer. The possible locations of attachment were speculated to be the electronegative atoms apart from the chlorine atoms due to valence considerations. The methylene group is attached to the nitrogen atom and forms a bond as observed in the MS/MS spectra of m/z 297, m/z 311, m/z 325 and m/z 339 which give m/z 183 as the base peak in all cases. Further experiments showed that there is cleavage of the methylated CAP molecule followed by cluster ion formation involving addition of methylene groups to the CAP fragment with m/z 183 to produce ions of m/z including m/z 297, m/z 311, m/z 325 and m/z 339. This process occurs in the mass spectrometer in the region housing the tube lens and is triggered when the ions are accelerated through this region by application of a negative tube lens offset voltage. This region affords collision of the charged droplets with a collision gas in this case nitrogen to strip the droplets of their solvent molecules. Experiments to follow the intensities of m/z 183, m/z 311, m/z 321, m/z 323, m/z 325 and m/z 339 as the tube lens offset voltage was varied were done in which the intensities of m/z 311, m/z 325 and m/z 339 were observed to be at their peak when the tube lens offset voltage was set at -40 V. When the tube lens offset voltage is swung to +40 V, thus decelerating the ions through the capillary skimmer region via the tube lens, the traditionally observed spectra with m/z 321, m/z 323 and m/z 325 were observed.

Flow‐injection chemiluminescence method for the determination of chloramphenicol based on luminol–sodium periodate order‐transform second‐chemiluminescence reaction

A new chemiluminescence (CL) reaction was observed when chloramphenicol solution was injected into the mixture after the end of the reaction of alkaline luminol and sodium periodate or sodium periodate was injected into the reaction mixture of chloramphenicol and alkaline luminol. This reaction is described as an order-transform second-chemiluminescence (OTSCL) reaction. The OTSCL method combined with a flow-injection technique was applied to the determination of chloramphenicol. The optimum conditions for the order-transform second-chemiluminescence emission were investigated. A mechanism for OTSCL has been proposed on the basis of the chemiluminescence kinetic characteristics, the UV-visible spectra and the chemiluminescent spectra. Under optimal experimental conditions, the CL response is proportional to the concentration of chloramphenicol over the range 5.0 × 10(-7)-5.0 × 10(-5) mol/L with a correlation coefficient of 0.9969 and a detection limit of 6.0 × 10(-8) mol/L (3σ). The relative standard deviation (RSD) for 11 repeated determinations of 5.0 × 10(-6) mol/L chloramphenicol is 1.7%. The method has been applied to the determination of chloramphenicol in pharmaceutical samples with satisfactory results.

Effector-Repressor Interactions, Binding of a Single Effector Molecule to the Operator-bound TtgR Homodimer Mediates Derepression

The RND family transporter TtgABC and its cognate repressor TtgR from Pseudomonas putida DOT-T1E were both shown to possess multidrug recognition properties. Structurally unrelated molecules such as chloramphenicol, butyl paraben, 1,3-dihydroxynaphthalene, and several flavonoids are substrates of TtgABC and activate pump expression by binding to the TtgR-operator complex. Isothermal titration calorimetry was employed to determine the thermodynamic parameters for the binding of these molecules to TtgR. Dissociation constants were in the range from 1 to 150 microm, the binding stoichiometry was one effector molecule per dimer of TtgR, and the process was driven by favorable enthalpy changes. Although TtgR exhibits a large multidrug binding profile, the plant-derived compounds phloretin and quercetin were shown to bind with the highest affinity (K(D) of around 1 microm), in contrast to other effectors (chloramphenicol and aromatic solvents) for which exhibited a more reduced affinity. Structure-function studies of effectors indicate that the presence of aromatic rings as well as hydroxyl groups are determinants for TtgR binding. The binding of TtgR to its operator DNA does not alter the protein effector profile nor the effector binding stoichiometry. Moreover, we demonstrate here for the first time that the binding of a single effector molecule to the DNA-bound TtgR homodimer induces the dissociation of the repressor-operator complex. This provides important insight into the molecular mechanism of effector-mediated derepression.

Development and Validation of a Thin-Layer Chromatographic Method for Determination of Chloramphenicol Residues on Pharmaceutical Equipment Surfaces

A thin-layer chromatographic (TLC) method with densitometric quantitation using the absorption reflectance mode at 280 nm was developed and validated for the determination of chloramphenicol residues in controlling pharmaceutical equipment cleanliness. Simulated samples at residue levels 0.5, 1, and 1.2 mg/m2 were prepared by spreading the calculated amount of chloramphenicol solution on a 10 dm2 stainless steel surface. After evaporation of the solvent, the residue was removed by 2 methanol-wetted cotton swabs, which were then extracted with methanol. The extract was applied on a high-performance TLC (HPTLC) silica gel F254 plate together with standards ranging from 10 to 60 ng. Plates were developed in a horizontal developing chamber from both sides (36 applications per plate) by using n-hexane-ethyl acetate (35 + 65, v/v) as developing solvent. The mean recovery (n=6) at 1 mg/m2 was 95.8%, and the coefficient of variation was 5.8%. The absolute detection limit was 3 ng, and the quantitation limit 10 ng. The method detection limit was 0.3 mg/m2 by swabbing 2.5 dm2 and 0.075 mg/m2 by swabbing 10 dm2. Chloramphenicol was stable on the plate 2 h before and 24 h after development. Additionally, it was stable during 7 days storage on the cotton swabs in the solvent at room temperature and in diluted standard solution stored in darkness at 4 degrees C. The method can be applied to routine control of pharmaceutical equipment cleanliness by sampling from the stainless steel surface areas of 2.5 to 10 dm2, and an acceptable residue limit of 1 mg/m2.

Determination of chloramphenicol in tablets by electrogenerated chemiluminescence

Chloramphenicol was determinate by electrogenerated chemiluminescence coupled to FIA using Ru(bpy)32+ luminescent complex. Chloramphenicol cause a decrease in luminescence intensity from the ruthenium complex that is proportional to its concentration between 5 x 10-5 and 1 x 10-3 mol L-1. The relative standard deviation was estimated as £ 1.5 % for 1 x 10-4 mol L-1 chloramphenicol solution of 12 successive injections. The chloramphenicol was determined in tablets with success and the soluble components of the matrix did not interfere in the luminescent emission. Results obtained with the luminescent procedure were not statistically different from those obtained by UV-spectrophotometry at the 95 % confidence level.

Development of a direct-binding chloramphenicol sensor based on thiol or sulfide mediated self-assembled antibody monolayers

A batch-type antibody-immobilized quartz crystal microbalance (QCM) system for detecting chloramphenicol (CAP) was developed. To bind an anti-CAP antibody onto the gold electrode surface of piezoelectric crystals, self-assembled monolayers (SAMs) of different thiols or sulfides were formed by a chemisorption procedure. Then, the anti-CAP antibody was covalently linked to the pre-formed monolayers by an activation procedure using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysulfosuccinimide. The antibody-immobilized QCM chip thus prepared was installed in a well holder and was measured for sensor response. Compared with the bare QCM chip and the QCM chip only coated with 3-mercaptopropionic acid (MPA), the antibody-immobilized sensor showed greatly enhanced frequency shifts by 10–50-fold after CAP injection. In this case, CAP detection which was indicated by steady-state resonant frequency shift was accomplished within 10 min. When CAP solution was injected into the reaction cell in 50 mM concentration, the frequency shifts obtained were, respectively, 530 and 505 Hz in case of thiosalicylic acid and MPA immobilization. Repeated use of the sensor chips up to eight times was possible after 1 min regeneration with 0.1 M NaOH. This system demonstrated a potential application of thiol or sulfide mediated SAMs as the pre-coatings of a real-time detection on CAP in solution.

Intracameral Levels of Intravenously Injected Fluorescein, Cefmenoxime, and Chloramphenicol in the Prostaglandin E2-Administered Eyes of Albino Rabbits

We evaluated the effects of inflammation and physicochemical nature of selected agents on the intracameral levels of intravenously injected drugs in albino rabbits. Transcorneal diffusion of prostaglandin E₂ (10, 50 or 250 µg/ml) using a glass cylinder was used to produce inflammation of the anterior segment in the right eyes. As a control, a vehicle was applied to the left cornea. Immediately, 2, 5, or 11 h after prostaglandin E₂ administration, a mixed solution of fluorescein, cefmenoxime, and chloramphenicol (50 mg each/kg body weight) was injected intravenously. One hour after injection of the drugs, the primary aqueous humor was withdrawn. The intracameral levels of protein and these drugs after prostaglandin E₂ administration increased at 1 h in a dose-dependent manner. These levels then gradually decreased. One hour after prostaglandin E₂ administration, the intracameral levels of protein and these drugs in the prostaglandin E₂-administered eyes were significantly higher than those in the vehicle-administered eyes, except chloramphenicol after administration of 10 µg/ml prostaglandin E₂. Our findings indicate that the intracameral levels of intravenously administered drugs are altered not only by the severity of inflammation but also by the properties of drugs.