Residue Analysis of Oxytetracycline in Milk Sample by Two Different Chromatographic Methods and Determination of Ionization Constant Values

In thepresent study, two analytical methods for the residue analysis of oxytetracycline in milk sample have been generated. InHPLC method, the analysis was performed on an X Terra RP-18 column at 25 °C with the mobile phase as methanol: water (20 : 80 )(v/v) modified to pH 5. For the second method capillary electrophoresis system was used. The analysis of oxytetracycline in milk sample could be achieved without using organic modifier in a 58 cm length capillary at a working voltage of 12 kV with 20 mM NaH2PO4-H3PO4(pH 7) by capillary electrophoresis. Tetracycline was used as internal standard in both methods. The results calculatedfrom both methods were compared to each other. The calculated data for drugs was checked with the data predicted by the SPARC on-line pKa estimator

Synthesis, characterization, and in vitro release of oxytetracycline loaded in pH-responsive CaCO3 nanoparticles

Alternative drug delivery for the treatment of resistant bacterial infections is necessary to bypass existing antibioticresistance mechanism and ensure direct delivery of the drug to the targeted site using locally sourced materialsto minimize cost in the long term. In this study, cockle shell-derived calcium carbonate aragonite nanoparticles(CS-CaCO3NP) was synthesized, loaded with oxytetracycline (OTC), and characterized using Zeta analysis,Transmission electron microscopy (TEM), FESEM, X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) andBrunauer–Emmett–Teller analysis. The loaded OTC-CS-CaCO3NP was further characterized after which the in vitrorelease of OTC was studied. A homogenously spherical CS-CaCO3NP was observed on TEM with a mean diameter of29.90 nm and −19.9 zeta potential which increased to 62.40 nm and −23.5, respectively, after OTC loading. XRD andFTIR analysis of OTC-CS-CaCO3NP revealed that OTC maintained its functionality and crystallinity. The formulationof OTC:CS-CaCO3NP in ratio 1:4 with drug encapsulating efficiency (71%) was used for in vitro release studies.OTC was sustainably released from OTC-CS-CaCO3NP over a period of 96 hours. Our results suggest that OTC-CSCaCO3NP is a promising nanoparticle antibiotic delivery system with efficient physicochemical and pharmacologicalproperties whose antibiotic properties should be further investigated.

Detection of Oxytetracycline Residues in Table Eggs in Khartoum State, Sudan

Aims: This study was conducted to detect the presence of oxytetracycline residues in table eggs in Khartoum State and to compare its level with the international acceptable maximum residue limits (MRLs). Study Design: One hundred and eighty table egg samples were randomly collected from 18 sale points in the three localities of Khartoum State, Sudan, (60 eggs from Omdurman, 60 eggs from Khartoum and 60 eggs from Khartoum North). Place and Duration of Study: Samples collected from Khartoum State during August and September, 2015. Methodology: Microbiological inhibition assay was used to screen the presence of antibiotic residues using Bacillus subtilis seeded in nutrient agar. Ninety positive egg samples from the microbiological inhibition assay were analyzed to detect the presence and quantity of oxytetracycline residues using HPLC. Results: Microbiological inhibition assay showed that 50% of the tested samples were positive for antibiotic residues in Omdurman, Khartoum and Khartoum North with 34(18.9%), 28(15.6%), and 28(15.6%) of the antibiotics respectively. HPLC results showed that 63(70%) were positive for oxytetracycline residues 19(10.5%) from Omdurman, 21(11.6%) from Khartoum and 23(12.7%) from Khartoum North. Conclusion: It was concluded that high percentage of table eggs contained oxytetracycline residues above the MRLs (0.2 ppm) that indicated the widespread misuse of oxytetracycline in poultry farms that may cause health hazards to consumers in Khartoum State. Therefore the study recommends compliance of drug withdrawal periods in poultry farms could reduce the incidence of antibiotic residues in consumed eggs.

Successful therapy in unusual generalized Dermatophilus congolensis infection in a calf based on modified in vitro disk diffusion test / Sucesso no tratamento de infecção generalizada em bezerra por Dermatophilus congolensis baseado em teste in vitro modificado de difusão com discos

Bovine dermatophilosis is a dermatitis characterized by typical focal or localized lesions with "paintbrush" aspect and occasionally as disseminated cutaneous disease. We report the case of a one-year-old Nelore female with history of chronic cutaneous disseminated lesions that appeared immediately after a rainfall period. Serous to purulent exudates, hair with tufted appearance, hyperkeratotic, non-pruritic, hardened, yellowish to brown, and coalescent crusty lesions were observed distributed all over its body. Removal of the crusts revealed ulcerated or hemorrhagic areas, with irregular elevated crusts like "paintbrush". Microbiological diagnosis enabled the identification of a microorganism, the Dermatophilus congolensis. Despite disseminated and chronic lesions, we obtained a successful therapy with parenteral therapy using long-acting tetracycline based on modified in vitro disk diffusion test. The present report highlights success therapy in uncommon generalized bovine dermatophilosis with selection of first-choice drugs based on modified in vitro susceptibility test, and need of responsible use of antimicrobials in livestock.(AU)

A dermatofilose bovina é uma dermatite caracterizada por lesões focais ou localizadas com aspecto de "pincel" e, ocasionalmente, como lesão cutânea disseminada. Relata-se o caso de uma fêmea bovina de um ano de idade, que foi atendida apresentando história de lesões cutâneas crônicas imediatamente após um período de alta pluviosidade. Ao exame clínico, lesões serosas a purulentas, com hiperqueratose, coalescentes, não pruriginosas, ressecadas, de coloração amarelada à acinzentada foram observadas distribuídas de modo generalizado pelo animal. A remoção das crostas revelou áreas ulceradas ou hemorrágicas, com crostas irregulares e elevadas semelhantes a "pincel". O diagnóstico microbiológico possibilitou a identificação do micro-organismo Dermatophilus congolensis. Apesar das lesões disseminadas e crônicas, a cura do animal foi obtida com tratamento parenteral usando oxitetraciclina de longa duração, baseado em teste in vitro de sensibilidade microbiana modificado. O presente relato ressalta o sucesso no tratamento de caso incomum de lesões generalizadas de dermatofilose bovina com respaldo de teste in vitro de sensibilidade modificado, bem como a necessidade do uso responsável de antimicrobianos em animais de produção.(AU)

Residues determination of oxytetracycline, tetrarcycline and chlortetracycline in zaosheng cattle meat by SPE-HPLC / 国际药学研究杂志

Objective To establish a method for simultaneous determination of 3 tetracyline antibiotics (TCs) oxytetra-cycline (OTC), tetracycline (TC), chlorotetecycline (CTC)) residues in Zaosheng cattle meat using solid phase extraction-high performance liquid chromatography (SPE-HPLC). Methods The samples were extracted by Na2EDTA-Mcllvaine buffer solution (pH=4.0), and 15% trichloroacetic acid (TCA) as the protein precipitation solution, then the targets were cleaned up and enriched by C18 solid phase extraction column. HPLC Mobile phase consisted of oxalic acid (0.01mol/L), acetonitrile as well as methanol. The detection wavelength was 350 nm and external standard method was adopted for quantification. Results The calibration curves of 3 TCs had good linearity with correlation coefficients of 0.998. The limits of detection of OTC, TC and CTC were 18, 15, 30 μg/kg, respectively, while their average recoveries were 76.10%-95.22%, with relative standard deviations (RSD) lower than 10% after optimized pretreatment and analytical conditions. Conclusion The method has high sensitivity, precision, and good repeatability, and can meet the needs of residue determination of TCs in meat.

Development of Fed-Batch Cultivation Strategy for Efficient Oxytetracycline Production by Streptomyces rimosus at Semi-Industrial Scale

ABSTRACTOxytetracycline (OTC) production byStreptomyces rimosus was studied in batch and fed-batch cultures in shake flask and bioreactor levels using semi-defined medium. First, the effect of glucose concentration on OTC production and growth kinetics was studied intensively. The optimal glucose concentration in the medium was 15 g/L. Higher glucose concentrations supported higher biomass production by less volumetric and specific antibiotic production. Based on these data, cultivations were carried out at semi-industrial scale 15 L bioreactor in batch culture. At bioreactor level, cell growth and OTC production were higher compared to the shake flask culture by about 18 and 38%, respectively. During the bioreactor cultivation, glucose was totally consumed after only 48 h. Thus, the fed-batch experiment was designed for mono-glucose feeding and complete medium feeding to increase the OTC production by overcoming carbon limitations. The results showed that the fed-batch culture using constant glucose feeding strategy with rate of 0.33 g/L/h produced 1072 mg/L. On the other hand, feeding with complete medium resulted in 45% higher biomass but less OTC production by about 26% compared to mono-glucose fed culture. A further improvement in this process was achieved in by keeping the dissolved oxygen (DO) value at 60% saturation by cascading the glucose feeding pump with the DO controller. The later feeding strategy resulted in higher antibiotic production, reaching 1414 mg/L after 108 h.

Effects of Tetracycline Son Soil Enzyme Activities in an Alluvial Soil.

Aims: To study the effect of various doses of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) on the enzymatic (DHA, acid phosphatase, alkaline phosphatase, urease and catalase) activity in sewage amended and un-amended alluvial soil. Methodology: A laboratory incubation study was conducted during 2012-2013 on an Aligarh farm alluvial soil. The enzymatic activity was studied in presence of various doses of three tetracycline antibiotics in soil; soil amended with sewage sludge; and mixture of sewage sludge and tetracyclines at different time intervals [(0 (4h), 7, 14, 21, 35, 56, 70,91d]. Results: Activity of all the studied enzymes was significantly inhibited for up to 14-21 days of incubation (14 d for DHA and acid phosphatase, 21 d for alkaline phosphatase, urease and catalase) and thereafter inhibition got weaker. The activity of all the studied enzymes decreased with increase in the doses of tetracyclines. Higher enzymatic activity was observed in sewage sludge amended soil than in the un-amended soil. Tetracyclines in presence of sewage sludge were found to have no appreciable effect on enzymatic activities. Conclusions: Dehydrogenase, acid and alkaline phosphatase, urease and catalase activity in tetracycline free soil was superior to soil containing antibiotics in the period of 2-3 weeks of incubation. The inhibition of soil enzyme activity was directly proportional to tetracycline concentration. In presence of sewage sludge, the studied enzymes activity initially increased up to 3 weeks and decreased thereafter. In presence of sewage sludge and antibiotics, the activity of enzymes remains almost unchanged. The activity of studied enzymes in soil was positively correlated to soil organic content.

Comparison between Source-induced Dissociation and Collision-induced Dissociation of Ampicillin, Chloramphenicol, Ciprofloxacin, and Oxytetracycline via Mass Spectrometry

Mass spectrometry (MS) is a very powerful instrument that can be used to analyze a wide range of materials such as proteins, peptides, DNA, drugs, and polymers. The process typically involves either chemical or electron (impact) ionization of the analyte. The resulting charged species or fragment is subsequently identified by the detector. Usually, single mass uses source-induced dissociation (SID), whereas mass/mass uses collision-induced dissociation (CID) to analyze the chemical fragmentations Each technique has its own advantages and disadvantages. While CID is most effective for the analysis of pure substances, multiple-step MS is a powerful technique to get structural data. Analysis of veterinary drugs ampicillin, chloramphenicol, ciprofloxacin, and oxytetracycline serves to highlight the slight differences between SID and CID. For example, minor differences were observed between ciprofloxacin and oxytetracycline via SID or CID. However, distinct fragmentation patterns were observed for ampicllin depending on the analysis method. Both SID and CID showed similar fragmentation spectra but different signal intensities for chloramphenicol. There are several factors that can influence the fragmentation spectra, such as the collision energy, major precursor ion, electrospray mode (positive or negative), and sample homogeneity. Therefore, one must select a fragmentation method on an empirical and case-by-case basis.

Extracción de Cxitetraciclina en carne de pollo: estudios de rendimiento con aumento de la fase polar del solvente de extracción / Oxytetracycline Extraction in Chicken Meat: Studies on Yield increasing Polar Phase in Extraction Solvent

El consumo de alimentos con residuos de oxitetraciclina (OTC) puede causar diversos efectos tóxicos en el humano. Con la finalidad de extraer y cuantificar dichos residuos en matrices biológicas, como carne de pollo, se han desarrollado diversos métodos. Dentro de los métodos propuestos el más empleado es la extracción líquido-líquido por ser sencillo, rápido y económico. Este tipo de extracción fue aplicada por Furusawa para OTC en pollo, empleando acetonitrilo/hexano en una proporción 5:4 obteniendo una recuperación del 88%. Este trabajo tuvo como objetivo estudiar la recuperación de OTC en carne de pollo ensayada por Furusawa, aumentando la proporción del solvente polar con respecto al hexano (2:1), para su posterior cuantificación mediante cromatografía líquida de alta resolución (HPLC). Para ello se utilizaron 24 porciones de 1 g de tejido muscular perteneciente al muslo de 3 pollos libres de antibióticos, las cuales se fortificaron con soluciones estándares de OTC de 0,1; 0,2; 0,5 y 1 µg/g, obteniendo 6 muestras fortificadas con cada concentración, las cuales fueron almacenadas por 12 horas a 4°C. La extracción del antibiótico se llevó a cabo con acetonitrilo/hexano en proporciones 5:4 y 2:1. En cada caso se evaluó la recuperación, precisión y sensibilidad. Tanto para la proporción 5:4 como 2:1, la concentración de 0,2 µg/g presentó la mayor recuperación, siendo 91,5 y 92,5%, respectivamente; sin embargo, al aumentar la concentración de OTC disminuyó la recuperación. La precisión se incrementó a la concentración de 0,5 µg/g, sin embargo, al duplicar la concentración a 1 µg/g disminuyó dicho parámetro. El límite de detección obtenido para la extracción de OTC con acetonitrilo/hexano en proporción 2:1 fue de 0,09 µg/g. Se recomienda realizar una desproteinización de la muestra previo al proceso de extracción.

Consumption of food that contains oxytetracycline (OTC) residues may produce several toxic effects in human beings. In order to extract and quantify such residues in biological matrices, like chicken meat, several methods have been developed. Among these methods, liquid-liquid extraction is the mostly used, because is quick, simple and inexpensive. This extraction method was applied by Furusawa for OTC in chicken, using acetonitrile/hexanes in a 5:4 proportion, obtaining an 88% recovery. The objective of this research was to study extraction of OTC in chicken meat assayed by Furusawa, raising polar solvent proportion in relation to hexanes (2:1), and further quantifying by means of high performance liquid chromatography (HPLC). Twenty four portions of 1 g from 3 OTC free chickens were fortified with OTC standard solutions: 0.1, 0.2, 0.5 and 1 µg/g, obtaining 6 fortified samples for each concentration, stored for 12 hours at 4°C. Antibiotic extraction was performed using acetonitrile/hexanes in 5:4 and 2:1 proportions. Recovery, precision and sensitivity were analyzed in all samples. Either 5:4 or 2:1 proportions, 0.2 µg/g concentration obtained the higher recovery, 91.5 and 92.5%, respectively; however when OTC concentrations raised, recovery became lower. Precision increased at 0.5 µg/g concentration, but, fell down when concentration duplicated: 1 µg/mL. Detection limit obtained for OTC extraction using acetonitrile/hexanes in 2:1 proportion were 0.09 µg/g. Deproteinization is recommended previously to extraction process.

Comparação entre as administrações tópica e sistêmica de oxitetraciclina no tratamento de vacas com dermatite digital papilomatosa / Efficacy of topical and systemic treatments with oxytetracycline for papillomatous digital dermatitis in cows

Comparou-se a eficiência dos tratamentos tópico e sistêmico com oxitetraciclina em vacas com dermatite digital papilomatosa (DDP) e determinaram-se a presença de resíduos desse antimicrobiano no leite e sua concentração no líquido sinovial e no plasma. Utilizaram-se o tratamento tópico com oxitetraciclina em pó (grupo 1) e o sistêmico de longa ação (grupo 2) em 16 vacas holandesas em lactação, acometidas por DDP. Obtiveram-se amostras de plasma, líquido sinovial e leite nos momentos: M0, antes dos tratamentos; M1, seis horas após o tratamento e em intervalos de 12 horas até M23 (264 horas pós-tratamentos). Avaliaram-se o grau de claudicação, a extensão da lesão e a concentração da oxitetraciclina pela cromatografia líquida de alta eficiência. Nas vacas do grupo 1, ocorreu redução das lesões e da claudicação, quando comparadas com as do grupo 2. Nenhuma das amostras de leite, de líquido sinovial e de plasma nos animais do grupo 1 foi positiva para oxitetraciclina. As amostras de leite dos animais do grupo 2, entre M1 e M23, apresentaram valores acima do limite máximo residual permitido para esse antimicrobiano. O tratamento tópico foi eficiente no tratamento de DDP, sem produzir resíduos no leite ou concentrações no plasma e no líquido sinovial. O tratamento sistêmico foi ineficiente para DDP, resultando em resíduos no leite, durante a avaliação.

The efficacy of topical versus systemic treatment with oxytetracycline for papillomatous digital dermatitis (PDD) in dairy cows was compared. Antimicrobial residues in milk and their concentrations in synovial fluid and plasma were analysed. Sixteen lactating Holstein cows with PDD lesions were topically treated with oxytetracycline powder (group 1) or long-acting oxytetracycline (group 2). Plasma, synovial fluid, and milk samples were collected in the following moments: M0 (before treatments); at six hours after treatments (M1), and at 12-hour intervals until 264 hours after treatments (M23). Lameness score and lesion size were evaluated. Analysis of oxytetracycline concentration was performed by high-performance liquid chromatography (HPLC). Cows in group 1 showed reduced lesion size and lameness score when compared to cows in group 2. None of the plasma, synovial fluid, or milk samples collected from cows in group 1 were positive to oxytetracycline. However, violative antimicrobial residues were detected in milk samples collected from cows in group 2, from M1 until M23. Topical application of oxytetracycline powder was an efficient treatment for PDD with no risk of violative antimicrobial residues in milk or increases its concentration in plasma or synovial fluid. The systemic administration of oxytetracycline was inefficient to treat PDD and caused violative residues in milk.

Determinación de residuos de oxitetraciclina en muestras De tejido bovino destinadas al consumo humano / Determination of oxytetracycline residues in samples of bovine tissues Used for human consumption

Las oxitetraciclinas (OTC) son antimicrobianos de amplio espectro que se han utilizado de manera indiscriminada en Medicina Veterinaria. Estos fármacos  pueden permanecer como residuos químicos en alimentos, lo que pudiera provocar graves problemas de Salud Pública. Entre estos problemas podemos mencionar: desarrollo de resistencia bacteriana a antimicrobianos, alergias, trastornos en la  osificación, dentición y efectos carcinógenos. En Venezuela no existe control en cuanto a la dosificación, frecuencia de aplicación y cumplimiento del tiempo de retiro de los fármacos; menos aún existen servicios de inspección oficial que vigilen la presencia de residuos y establezcan los límites máximos de residuos sugeridos (LMRS) en productos alimenticios de origen animal. Para evaluar la presencia de residuos de OTC, fueron utilizadas  muestras de músculo, hígado y riñón, de  bovinos procedentes de la Beneficiadora Industrial Maracay. En el presente ensayo se utilizó el LMRS de 250 ng/g, establecido por la Organización Mundial de la Salud (OMS). En un 89,3% de las muestras se detectaron residuos de OTC con unnivel promedio de 781,54 ng/g ±1033,29, lo cual resultó ser superior a lo establecido como LMRS. El promedio de residuos  para cada tejido resultó ser de 533,84 ng/g ±527,92 para músculo, 917,16 ng/g ± 1295,41, para hígado y 819,14 ng/g ±859,18 para riñón. Estos hallazgos confirman el incumplimiento de los tiempos de retiro en la práctica pecuaria en nuestro país.

Oxytetracyclines (OTC) are wide spectrum antimicrobials that have been used indiscriminately in Veterinary Medicine. These drugs can remain as chemical residues in foodstuff, which could lead to serious health problems, such as development of bacterial resistance, allergies, ossification and dentition disturbances, and carcinogenic effects. In Venezuela, there are no government regulations regarding dosage regimens, frequency of application and withdrawal times for OTCs. Neither there are official inspection agencies that scrutinize the presence of residues and establish the suggested maximum limits of residues (MLSRs) for food products of animal origin. This research evaluated the presence of OTC residues in organ samples of bovine used for human consumption, from Beneficiadora Industrial Maracay. Samples of muscle, liver and kidney were used. In order to compare de values obtained in this investigation, we used the MLRs values established by the World Health Organization (WHO), such values correspond to 250ng/g. Results of this investigation, show that OTC were detected in 89.3% of all tissuesamples evaluated, with a mean OTC residue of 781,54 ng/g ±1033,29. These values are higher than the already established MLSRs. The mean OTC value for each tissue sample was: 533,84 ng/g ±527,92 for muscle; 917,16 ng/g ± 1295,41 for liver and; 819,14 ng/g ±859,18 for kidney respectively. These results suggest that there is not an adequate monitoring for withdrawal times in terms of OTC in veterinary practice.

DETERMINATION OF TETRACYCLINE AND OXYTETRACYCLINE BY FLOW-INJECTION CHEMILUMINESCENCE METHOD / 药物分析学报

Objective To establish a rapid and precise continuous flow-injection chemiluminescence method for the determination of tetracycline and oxytetracycline. Methods In NaOH solution, tetracycline and oxytetracycline can sensitize obviously the chemiluminesence (CL) intensity of the reaction of luminol with KIO4, the sensitized CL intensity is proportional to the concentration of tetracycline and oxytetracycline. So, a new flow-injection CL method has been developed. The optimum chemical conditions for the CL reaction were investigated. Results Under the optimized conditions (KIO4 concentration: 1.0×10-5 mol/L; NaOH concentration: 0.1mol/L; luminol concentration: 1.0×10-4mol/L), tetracycline and oxytetracycline were determined. The linear range of the working curves was 1.0×10-7 -1.0×10-4g/mL, the detection limits was 1.0×10-8g/mL and 1.1×10-8g/mL, and the relative standard deviation was 2.6% (CS=1.0×10-6g/mL; n=11) and 2.0% (CS=1.0×10-6g/mL; n=11) respectively. Conclusion The method is simple, rapid, and sensitive, and it has been successfully applied to the the determination of tetracycline and oxytetracycline tablets, the mean recoveries being 99.7% and 98.8% respectively.

Disinfection effect of root canal with non-filling medication in root canal therap / 中国基层医药

Objective To observe the clinical disinfection effect of root canal with non-filling medication.Methods 50 patients who required root canal therapy for apical period(acute or chronic) or pulp necrosis were involved in the study.Non-filling medication on the root canals were taken bacteria from the root canals were collected and cultured before and after the treatment.Results Bacteria were detected in every specimen,which were mixture of aerobes and anaerobes.One week later,only two strain were detected in two specimen.Conclusion Non-filling medication can be used as an effective disinfection to sterilize root canal.

Study on Determination Methods for Dissolution of Oxytetracycline Tablets / 中国药房

OBJECTIVE:To establish a determination method for dissolution of oxytetracycline tablets. METHODS:The content of oxytetracycline was determined by UV spectrophotometry at detection wavelength of 271 nm. Dissolution of oxytetracycline tablets was detected by slurry process using 0.01 mol?L-1 hydrochloric solution as solvent. RESULTS:The linear range of oxytetracycline was 4～32 IU?mL-(1r=0.999 9)with an average recovery of 100.1%(RSD=0.65%). The dissolution in 45 min were all above 75%. CONCLUSION:Established method in this study can be used to determine dissolution of oxytetracycline tablets.

Determination of the Potencies of Oxytetracycline Crude Drug and Its Tablets by Turbidimetric Method / 中国药房

OBJECTIVE:To establish a turbidimetric method for the determination of the potency of the crude drugs and tablets of oxytetracycline. METHODS: By turbidimetric method in which Staphylococcus aureus was used as the test organism with biomass concentration of 1.0%～1.5% (V/V). The culture temperature was 37 ℃ and the culture time was about 4 h. The method was compared with the cup-plate method in potency. RESULTS: The linear range of oxytetracycline was 0.05～0.4 IU?mL-1. The average recovery of the crude drug of oxytetracycline was 99.59% (RSD=2.0%) and that of oxytetracycline tablets was 99.51% (RSD=1.91%), showing no significant difference as compared with the cup-plate method in contents. CONCLUSIONS: The method was sensitive and rapid yet with few influencing factors thus applicable for the determination of the potencies of oxytetracycline and its tablets.