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M Medenica

Publications and source records attributed to M Medenica.

At least 19 recordsLinked to original sources
PubMed2005

Development of liquid chromatographic method for fosinoprilat determination in human plasma using microemulsion as eluent.

Fosinopril sodium presents a prodrug for the active angiotensin converting enzyme (ACE) inhibitor, fosinoprilat. The dual elimination of fosinoprilat by the liver and the kidney distinguishes fosinopril from other angiotensin converting enzyme inhibitors. Such ways of elimination are important for antihypertensive therapy of patients on haemodialysis. The paper presents development and evaluation of a new and sensitive liquid chromatographic (LC) method for the analysis of fosinoprilat in plasma obtained from patients on haemodialysis. A microemulsion system mixture as mobile phase has been used for the separation and analysis of fosinoprilat in plasma samples. The plasma samples were injected directly onto the HPLC system (Waters Breeze) after appropriate sample dilution with mobile phase. Separations were performed on the Bakerbond ENV 4.6 mm x 150 mm, 5 microm particle size column with UV detection at 220 nm. The flow rate was 1.00 mL min(-1). The mobile phase consisted of 1.0% (w/v) of diisopropyl ether, 2.0% (w/v) of sodium dodecyl sulphate (SDS), 6.0% (w/v) of n-propanol and 91% (w/v) of aqueous 25 mM di-sodium hydrogen phosphate, pH adjusted to 2.8 with 85% orthophosphoric acid. The developed method was then subjected to method validation according to the criteria stated in the FDA bioanalytical method validation guidance. The results for specificity, linearity, low limit of quantification (LLOQ), precision, accuracy and stability were within the accepted criteria. The unique approach applied in this paper makes possible the determination of fosinoprilat even in the presence of metabolites of other drugs, so the method can be used for obtaining the reliable results in a fast and simple way.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2005

Development and validation of RP-HPLC method for cetrimonium bromide and lidocaine determination.

The simple and rapid RP-HPLC method, for the simultaneous determination of lidocaine and cetrimonium bromide in the presence of pellet color corrigent, was developed. Separations were performed on a Beckman Ultrasphere ODS 4.6 mm x 15 cm, 5 microm particle column at 40 degrees C. The mobile phase consisted of water phase and acetonitrile (72:28 V/V), pH value of the mobile phase was adjusted to 2.0 with 85% ortophosphoric acid. Bisacodil was used as an internal standard. The flow rate was 1 ml/min and UV detection was performed at 208 nm. The proposed RP-HPLC method was validated and all the parameters for the validation of the method are given. According to the obtained results, the developed method was found to be suitable and accurate for the determination of these drugs in commercial formulations.

Acetonitriles↗
PubMed2004

Experimental design in reversed-phase high-performance liquid chromatographic analysis of imatinib mesylate and its impurity.

For the determination of the optimal RP-HPLC chromatographic conditions for the separation of imatinib mesylate and its impurity STI 509-00 experimental design 2(4) was applied. All the factors that affect imatinib mesylate/STI 509-00 separation, as well as their mutual interactions were investigated. Methanol and triethylamine content in the mobile phase, pH of the mobile phase and column temperature were independent variables or factors to be investigated in two levels: "low" and "high". Capacity factor was chosen as a dependent variable. From the experimentally determined capacity factor values, it was defined the factors that affect to chromatographic system the most. Applying response surface methodology the appropriate graphs were constructed from experimental points and optimal chromatographic conditions for the separation were defined. Optimal conditions for the separation of imatinib mesylate and STI 509-00 were obtained using X Terra 150 mm x 4.6 mm, particle size 5 microm column at 25 degrees C. Mobile phase consisted of 250 ml of methanol, 740 ml of water and 10 ml of triehylamine. pH of water phase was adjusted to 2.4 with 85% orthophosphoric acid and then methanol was added.

Antineoplastic Agents↗
PubMed2004

Reversed-phase liquid chromatography analysis of imatinib mesylate and impurity product in Glivec capsules.

The reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed and validated for the simultaneous determination of imatinib mesylate and of the impurity product in Glivec capsules (Novartis, Switzerland). Separations were performed on a X Terra 150 mm x 4.6 mm, 5 microm particle size column at 25 degrees C. The mobile phase was a mixture of methanol-water-triethylamine (25:74:1, v/v/v) with flow rate of 1.0 ml min(-1). pH value of water-triethylamine (TEA) was adjusted to 2.4 with orthophosphoric acid before adding of methanol. UV detection was performed at 267 nm. Acetaminophen was used as an internal standard. The method was validated statistically for its selectivity, linearity, precision, accuracy and robustness. Due to its speed and accuracy, the method may be used for quality control analyses.

Antineoplastic Agents↗
PubMed2003

Optimization of the RP-HPLC method for multicomponent analgetic drug determination.

The optimization of RP-HPLC method defined the simultaneous influence of some important conditions, such as the mobile phase composition, pH of the mobile phase and temperature, on the separation and determination. The RP-HPLC method was done for the determination of paracetamol, caffeine and propyphenazone in a multicomponent pharmaceutical dosage form. The separation factor values define the optimal conditions, which were confirmed by analysing the appropriate mathematical models. The chromatographic system Hewlett Packard 1100 consisted of a HP 1100 pump, HP 1100 UV-VIS detector and HP integrator. Separations were performed on a Beckman Ultrasphere ODS 4.6 x 150 mm, 5 microns particle size column. Samples were introduced through a Rheodyne injector valve with a 20 microL sample loop. UV detection was performed at 265 nm and phenobarottons was used as an internal standard. The optimization was performed within the pH range from 2.5 to 6.0; temperature range from 20 degrees C to 55 degrees C and composition of the mobile phase methanol-water from (30:70 V/V) to (65:35 V/V). The three-D graphs, constructed with sixty-four experimental points, confirmed the optimal conditions for the determination of the investigated analgetic drugs.

Acetaminophen↗
PubMed2000

The derivative spectrophotometric and IP-RP-HPLC determination of the Lometazid tablets.

In this paper the second-derivative spectrophotometric and ion-pair reversed-phase high performance liquid chromatographic methods for the simultaneous determination of some diuretic ingredients are described. Optimal conditions of both techniques for the quantitative analysis of the two-component diuretic mixture of the Lometazid tablets were settled. The second-derivative order of the spectra in sodium hydroxide with the wavelength modulation was used. For the determination of amiloride hydrochloride the 'zero-crossing' technique was applied, but for methyclothiazide the peak amplitude had to be corrected. In the ion-pair RP-HPLC technique tetrabutylammonium hydroxide was applied as an ion-pairing agent using acetonitrile-phosphate buffer (45:55 v/v) as a mobile phase. The validation was done of both proposed methods.

Amiloride↗
PubMed2000

Second-derivative spectrophotometric assay of pseudoephedrine, ibuprofen and loratadine in pharmaceuticals.

In this paper the second-derivative spectrophotometric method for the simultaneous determination of pseudoephedrine (CAS 90-82-4) in the combinations with ibuprofen (CAS 15687-27-1) and loratadine (CAS 79794-75-5) is described. Optimal conditions for the quantitative analysis of coated tablets (Test I) and tablets (Test II) were settled. The second-derivative order of the spectra in ethanol with the wavelength modulation was used. For the quantitative assay for all of the investigated substances in the laboratory mixture or in respective pharmaceutical dosage forms the "zero-crossing" technique was applied. The authors propose this second-derivative spectrophotometry for a rapid, simple, precise and accurate determination of the mentioned tests or a corresponding multicomponent mixture.

Anti-Allergic Agents↗
PubMed1999

Reversed-phase ion-pair HPLC determination of some water-soluble vitamins in pharmaceuticals.

A reversed-phase ion-pair high-performance liquid chromatografic method (RP-IPC) was developed to assay some water-soluble vitamins in solution dosage forms. Vitamins of the B-group B1, B2, B3, and B6, including vitamin C were determined in Oligovit coated tablets. In Beviplex coated tablets the vitamins B1, B2, B3, B6 and p-aminobenzoic acid were analysed. Hexanesulphonic acid sodium salt and triethanolamine in water methanol were used as mobile phase with adjusting pH to 2.8 with orthophosphoric acid. Phenol was used as an internal standard. For quantitative simultaneous analysis of vitamins in pharmaceutical formulations, the method of internal standard was used. All parameters for the validation of the method are given.

Ascorbic Acid↗
PubMed1998

Electrochemical determination of ibuprofen.

Two simple and accurate electrochemical methods for the determination of ibuprofen (CAS 15687-27-1) as a bulk drug and as an active compound in pharmaceutical formulations are presented. For the potentiometric determination of ibuprofen sodium hydroxide and triethanolamine were used as titrants. The influence of different solvents, such as water, methanol, acetonitrile, dimethyl sulfoxide and N,N-dimethylformamide, on the conductometric titrations was investigated. The same titrants as in the potentiometric titrations were used. The methods are accurate and results are reproducible in quantities ranging from 1 to 10 mg of ibuprofen in analysed pharmaceutical dosage forms. The relative standard deviation (n = 10) varies over the range 0.38-1.63%.

Electrochemistry↗
PubMed1996

Interleukin-2 associated linear IgA bullous dermatosis.

Linear IgA bullous dermatosis (LABD) in adults is characterized by subepidermal bullae associated with a linear deposition of IgA at the basement membrane zone. Its cause is unclear, although it appears to have an immune-mediated basis. The development of LABD in a cancer patient undergoing immunotherapy has been described in the French literature. We describe a similar case of LABD arising in a patient while undergoing interleukin-2 immunotherapy for renal cell carcinoma.

Aged↗