Method For Determination Of Theophylline Research Articles

A sensing platform based on zinc-porphyrin derinative in hexadecyl trimethyl ammonium bromide (CTAB) microemulsion for highly sensitive detection of theophylline

A new porphyrin-based sensing platform in hexadecyl trimethyl ammonium bromide (CTAB) microemulsion is developed for highly sensitive detection of theophylline. In this sensing system, the zinc-porphyrin-cinnamic acid conjugate (Zn-TPPCA) works as fluorescence probe while theophylline can decrease fluorescence intensity of the probe. Further studies indicate the linear relationship between the fluorescence quenching value and the concentration of theophylline within a given range. And the introduction of CTAB microemulsion can greatly enhance sensibility and stability of this detecting system and facilitate the detection of theophylline. On the basis above, a highly sensitive sensing platform for theophylline is created with a low limit of detection (LOD) of 0.0083 μg mL−1 under the optimal detection conditions. And further application of this method in determination of commercially available theophylline preparation shows excellent results. Subsequent studies on quenching mechanism indicate that static quenching appears between Zn-TPPCA and theophylline. Therefore, this work provides not only a highly sensitive method for determination of theophylline but also further evidence for creation of biosensors for drugs with porphyrin derivatives.

EDTA salt modified carbon paste electrode for square wave voltammetric determination of theophylline in pharmaceutical tablet formulation.

In this study, a square wave voltammetric method for determination of theophylline in tablet formulation based on EDTA salt modified carbon paste electrode is presented. CV, FT-IR, and EIS results confirmed modification of the carbon paste with EDTA salt. In contrast to the unmodified carbon paste electrode, the modified carbon paste electrode showed irreversible oxidation of theophylline with considerable current enhancement. Investigation of the effect of scan rate on the Ip and Ep response of the modified electrode for theophylline revealed predominantly diffusion controlled oxidation kinetics. Under the optimized conditions, square wave oxidative peak current of theophylline in pH 7.0 PBS showed linear dependence on concentration in the range 10–200 μM with determination coefficient (R2), limit of detection, and limit of quantification of 0.99782, 0.0257 μM, and 0.0857 μM, respectively. Detection of an amount of theophylline in the analyzed tablet formulation with 1.85% error from its nominal content (120 mg/tablet) confirmed the accuracy of the developed method. Spike and interference recovery results of 98.59%, and 95.7–100%, respectively validated the applicability of the developed method for determination of theophylline content in tablet samples.

Rapid Determination of Theophylline, Theobromine and Caffeine in Dietary Supplements Containing Guarana by Ultra-Performance Liquid Chromatography

A rapid and simple method for determination of theophylline, theobromine and caffeine in dietary supplements containing guarana by ultra-performance liquid chromatography (UPLC) has been developed. Theophylline, theobromine and caffeine were extracted from finely powdered samples with water in a boiling water bath for 20 min, then the extracts were filtered and the filtrates were subjected to UPLC. Liquid samples were diluted with water and filteres, and the filtrates were subjected to UPLC. UPLC separation was performed on an AQUITY UPLC BEH C18 column (2.1 mm i.d.x50 mm, 1.7 microm, Waters) with 10 mmol/L ammonium acetate buffer (pH 4.0)-acetonitrile gradient and eluates were monitored at 275 nm. The recoveries of theophylline (spiked at 200 microg/g [tablet] and 50 microg/mL [liquid]), theobromine (spiked at 200 microg/g [tablet] and 50 microg/mL [liquid]) and caffeine (spiked at 1,000 microg/g [tablet] and 250 microg/mL [liquid]) were 97.6-98.7%, 97.3-99.7%, 97.1-105.4%, respectively. The quantitation limits of theophylline, theobromine and caffeine were 10 microg/g (seed, seed powder, tablet and capsule) and 2.0 microg/mL (liquid) each. When this analytical method was applied to commercial dietary supplements, theophylline, theobromine and caffeine were found at concentrations of 4.45 mg/tablet, 5.48 mg/tablet, 139 mg/tablet, respectively. Taking 4 tablets of this product according to the directions on the package could be dangerous to consumers because of possible overdosing of these ingredients.

A liquid chromatographic method for determination of theophylline in serum and capillary blood — a comparison

A simple, fast and reliable liquid chromatographic method for the determination of theophylline in serum and capillary blood after a solid phase extraction is described for therapeutic drug monitoring. The employment of capillary blood permits the determination of an individual drug profile and other pharmacokinetic studies in neonates and infants. There were no differences in venous- and capillary-blood levels but these values compared poorly with those in serum. An adjustment of the results by correction of the different volumes of serum and blood by haematocrit was unsuccessful. Differences in the binding of theophylline to erythrocytes could be an explanation for the differences in serum at blood levels of theophylline.

4782016 Analytical element and method for determination of theophylline by enzyme inhibition: Gary Norton assigned to Eastman Kodak Company

4782016 Analytical element and method for determination of theophylline by enzyme inhibition: Gary Norton assigned to Eastman Kodak Company

Sulfonium salts as derivatizing agents : 2. Determination of theophylline in plasma by automated gas chromatography

An automated gas chromatographic method for determination of theophylline in plasma is described. A novel feature of this assay is the use of triethylsulfonium hydroxide as an on-column alkylating agent. A simple extraction procedure together with automated sample injection and data processing has facilitated processing of large numbers of samples generated in pharmacokinetic studies. The between-run coefficient of variation was 2.2% at 5 μg/ml ( n=5) and 3.9% at 15 μg/ml ( n=6). Within-run coefficient of variation was 2.4% at 5 μg/ml ( n=9) and 3.3% at 15 μg/ml ( n=6). Accuracy was 105% at a concentration of 5 μg/ml and 102% at 15 μg/ml.

4782017 Analytical element and method for determination of theophylline by enzyme inhibition: Paul H Frickey, Gary E Norton assigned to Eastman Kodak Company

4782017 Analytical element and method for determination of theophylline by enzyme inhibition: Paul H Frickey, Gary E Norton assigned to Eastman Kodak Company

Highly sensitive immunoliposome assay of theophylline.

A highly sensitive and reproducible immunoassy method for determination of theophylline was developed by using large unilamellar liposomes. Vesicles incorporating theophylline-phosphatidylethanolamine conjugate on the membrane surface as a sensitizer and including a fluorescent marker, calcein, were prepared by the reverse-phase evaporation method from mixtures of phosphatidylcholines containing various fatty acids and cholesterol. Competitive binding of specific antibody to the analyte drug and the sensitizer on the liposomal membrane resulted in lysis of liposomes, and consequently the amount of entrapped calcein that leaked out was inversely proportional to the concentration of the analyte. From studies of various parameters influencing liposome lysis, it was concluded that the chain length of fatty acid most strongly affected the calcein release. The proposed system is simple, rapid, precise, and sensitive to nanomolar concentrations of theophylline. Furthermore, the sensitized liposomes were stable and gave reproducible results. The principle of this assay should be applicable to routine analysis of a wide variety of drugs in biological samples for the purpose of clinical diagnosis or monitoring.

The liquid chromatographic determination of theophylline in untreated plasma by simple direct injection

A liquid chromatographic method for determination of theophylline by direct injection of untreated plasma samples is described. Theophylline is detected without interference from related compounds such as paraxanthine. A precolumn venting technique is used which considerably increases column life. The lifetimes of the separation columns are unaffected by plasma injections whereas the precolumn has to be changed after 140 injections (10 μl of plasma). The peak purity of theophylline is examined spectrophotometrically. Determinations are performed by external standardization with recoveries close to 100% with a precision better than 2.3% (RSD).

Interference in the proposed selected method for determination of theophylline by liquid chromatography.

Journal Article Interference in the proposed selected method for determination of theophylline by liquid chromatography. Get access J H Jonkman, J H Jonkman Search for other works by this author on: Oxford Academic Google Scholar R A de Zeeuw, R A de Zeeuw Search for other works by this author on: Oxford Academic Google Scholar R Schoenmaker R Schoenmaker Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 28, Issue 9, 1 September 1982, Pages 1987–1988, https://doi.org/10.1093/clinchem/28.9.1987 Published: 01 September 1982

A Direct Injection HPLC Procedure for the Quantitation of Theophylline in Blood and Saliva*†

A rapid and sensitive method for determination of theophylline In serum or saliva specimens utilizing high-pressure liquid chromatography (HPLC) is described. The analysis is performed on 2 /~L of specimen which does not require chemical manipulation prior to analysis. Studies comparing spiked aqueous samples of theophylline to spiked serum samples Indicate that total theophylllne Is determined by this procedure. The method was used to compare capillary and venous blood and saliva theophylllne concentration In healthy adult volunteers after administration of 200 mg theophylllne every six hours for two days. The small sample size required makea the determination Ideal for neonatal and pediatric use.

Simultaneous determination of theophylline and its metabolites in urine

SummaryA quantitative method for the simultaneous determination of theophylline (THP) and its metabolites, 1,3-dimethyluric acid (1,3-DMU), 1-methyluric acid (1-MU) and 3-methylxanthine (3-MX), in urine is described, using a preliminary extraction step with ‘Extreluf column and high pressure liquid chromatographic separation. Urinary excretion data of theophylline and its metabolites from 2 healthy male volunteers on a regular diet demonstrated high background values of 1-MU, to a lesser degree for 3-MXandTHP, and virtually none for 1,3-DMU, when the subjects were not receiving theophylline. Observed increments {above background values) following single-dose (375 mg) administrations of theophylline, orally and rectally, demonstrated 1,3-DMU as the predominant urinary excretory product together with 3-MX as an additional urinary metabolite, while the virtual absence of any increments in the 1-MU metabolite would indicate that biotransformation of theophylline to the 1-MU pathway is minimal or insignificant...

Gas-chromatographic/mass-spectrometric determination of theophylline in whole blood.

We describe a combined gas-chromatographic mass-spectrometric method for determination of theophylline in whole blood. With use of a probability-based matching approach, the extensive gas-chromatographic interference did not affect mass-spectrometric quantitation of theophylline. Concentrations expected and found were linearly related from 1 to 60 mg/liter; the run-to-run coefficient of variation was less than 8%, within-run less than 6%. Some other xan-thines and drugs frequently co-administered with theophylline did not affect results. Only 0.2 ml of blood is required, which makes the procedure useful for monitoring theophylline in newborns and pediatric populations.

Specific thin-layer chromatographic method for the determination of theophylline in plasma in the presence of some other drugs

A simple spectrodensitometric method for the direct determination of theophylline was developed from measurement of the absorbance of the compound on silica gel thin layers irradiated at 275 nm. Quantities as low as 0.010 μg can be detected and a linear relationship was obtained between peak area and the amount of the drug in the spots from 0.025–0.200 μg. The recovery over the usual range of plasma concentration (2.5–20 μg/ml) was 95–107%. The method is sufficiently sensitive and specific for clinical purposes and the time for the assay is about 2 h. Caffeine, frequently present in human plasma, was well separated from theophylline at all concentration levels as were several other drugs commonly used in respiratory problems.