In vitro antibacterial susceptibility of different brands of oral levofloxacin 250 mg tablet against Staphylococcus aureus and Escherichia coli

Antibiotics are not only used in morbidity but also help in prevention of infection. The irrational use of broad spectrum antibiotics is now increasing the resistance against pathogens. This present study has been carried out to evaluate the in-vitro antibacterial effect of levofloxacin against clinical isolates. According to Clinical and Laboratory Standards Institute [CLSI] guidelines, minimum inhibitory concentrations 90% [MIC90] of the levofloxacin tested were evaluated by an agar dilution method. Total 63 clinical isolates Staphylococcus aureus [n=34] and Escherichia coli [n=29] were collected from different hospitals at Karachi and were evaluated MIC90 of eleven different brands of levofloxacin tablet [250 mg]. Levofloxacin [Reference] was tested against E.coli standard [American Type Culture Collection] [ATCC=25922] with [MIC90; 0.03micro g/ml] and compared with different eleven brands of levofloxacin tablets 250mg [MIC90; 0.5micro g/ml -16.0micro g/ml]. Levofloxacin [Reference] sensitivity against S. aureus standard [ATCC=25923] is [MIC90; 0.12micro g/ml] and similarly when it was compared with same levofloxacin tablets [MIC90; 0.5-16.0micro g/ml]. It has been concluded by the present study, a large number of strains of bacteria have shown better bactericidal action of different brands of levofloxacin and nearly all commercialized drugs were appropriate for therapeutic use

Effect of stabilizers on the chemical and photodegradation of ascorbic acid in aqueous solution

Ascorbic acid [vitamin C] is susceptible to light and air and forms various degradation products. A number of stabilizers have been used to study their effect on the degradation of ascorbic acid [AH2] in dark and light at pH 4.0 and 6.0 alone and in combination with citric and tartaric acids. The assay of AH2 in degraded solutions was performed by a specific UV spectrometric method. The degradation product of AH2 at pH 4.0 and 6.0 was identified as dehydroascorbic acid. The degradation of AH2 has been found to follow first-order kinetics. The apparent first-order rate constants, t90 and percent inhibition in rate in the presence of stabilizers and the second-order rate constants for the interaction of stabilizers with AH2 have been determined. The highest stabilizing effect on AH2 was found by sodium metabisulfite, followed by sodium sulfite, sodium bisulfate, sodium thiosulfate and thiourea. The pH of the solutions has also been found to influence the degradation of AH2 as the rates are higher at pH 6.0 compared to those of pH 4.0, probably due to the ionization of AH2. A synergistic effect has been observed when citric or tartaric acid was added to the solutions containing stabilizers where citric acid showed comparatively better effect

Analysis of amino acids by high performance liquid chromatography

Amino acids are the building blocks of proteins and are considered as the key precursors for the formation of hormones and low molecular weight nitrogenous substances with biological importance. Since the analysis of amino acids has been carried out for both qualitative and quantitative purposes with an aim to study their levels in the plasma concentration, the quantitative determination, in particular, also helps in the diagnosis of different diseases associated with their deficiency. This review article deals with the determination of amino acids by chromatographic methods which include ion-exchange chromatography [IEC], high performance liquid chromatography [HPLC], reverse phase-high performance liquid chromatography [RP-HPLC] and ultra-performance liquid chromatography [UPLC]. The review will also give an idea for the preparation of samples, derivatization methods for the analysis of amino acids [direct and indirect methods] and separation of amino acids by high performance liquid chromatographic technique

Heavy metals accumulation in fruits and vegetables grown on sewage sludge and that of river water

In this study the crops cultivated on the application of sewage sludge were investigated. The crops grown included lady finger [okra], round gourd, smooth luffa, spinach, pumpkin, red pepper, green pepper and the fruits [pomegranate, mango, lemon, java plum, guava, banana, melon]. Results showed that sewage irrigation significantly increased total heavy metal contents in different organs [leaf, peel and pulp] of the crops in comparison to river water. The sewage water carried a very high load of Pb, Fe, Cu, Zn, Mg, Ca and other heavy elements. Maximum concentration in lady's fmger was for Mg followed by Zn, Cu, Ca, Fe, Pb and Co. There was significant increase in Mg concentration in leaf at 73.20 mg ke. Concentrations of Zn, Cu, Ca, Fe, Pb and Co were lower varying from 0.30 to 1.0 in leaf, 0.50 to 1.60 in peel and 0.70 to 1.70 in pulp. The accumulation of heavy metals by other vegetables was similar except spinach which showed high content of Fe at 39.0 mg kg-' in leaf. Plants fed on sewage water produced fruits showing heavy metals accumulation. It appeared that the metals accumulated and distributed between tissues in nearly the same proportion as in the vegetables. The river water fed vegetables and fruits, however, showed lesser accumulation of the heavy metals

Physicochemical, biochemical and antioxidant properties of ascorbic acid

Ascorbic acid [Vitamin C] is an important micronutrient that plays as a redox cofactor and catalyst in biological system. It is particularly useful in the cure and prevention of scurvy. It was originally isolated from lemon, cabbage and peprica. Ascorbic acid is essential for collagen formation and metabolism of phenyl alanine, tyrosine and hydroxyphenyl alanine [dopa]. The minimum daily requirement of vitamin C in adult is 40-60 mg. In this review chemical structure, physicochemical characteristics, chemical stability, biochemical functions and antioxidant activity of ascorbic acid have been mentioned

Clinical analysis, metabolism and bioavailability of thiamine

Thiamine is a component of vitamin B-complex and is used in the treatment of beriberi. The active form of the vitamin is thiamine pyrophosphate [TPP] which serves as a co-enzyme in various biochemical reactions. It is commercially available in the form of vitamin B-complex and multivitamin preparations. The clinical analysis of the vitamin and its esters is carried out by spectrophotometric, fluorimetric, high performance liquid chromatographic and flow-injection turbidimetric methods. The rates of catabolism and loss of thiamine indicate that in the absence of the vitamin, functional and clinical abnormalities occur in humans within a few weeks period. Thiamine absorption takes place in the intestine by two parallel mechanisms, i.e., saturable active transport and simple diffusion. The bioavailability of thiamine can be assessed by determining maximal thiamine concentration [Cmax] and its time [tmax] in plasma and hemolysates, the area under concentration time curve [AUC], and thiamine excretion in 24-hr urine