Sci. Pharm., Volume 68, Issue 3 (September 2000) – 10 articles , Pages 229-328

The seasonal depending variations of the essential oils of the needles with twigs of Bulgarian Douglas fir (Pseudotsuga menziesii, Pinaceae) were analyzed by GC-FID, GC-MS and olfactoric evaluation. In totally 8 investigated essential P. menziesii oils about 60 compounds could be identified with monoterpenes (especially sabinene and β-pinene) as main constituents. The antimicrobial effects against bacteria, fungi and worms of these volatiles as well as their olfactoric properties will be discussed. Full article

The essential oil of the aerial parts of Aristolochia indica Linn. (Anstolochiaceae) from South-India was analyzed by gas chromatographic-spectroscopic (GC-FID and GC-MS) and olfactoric methods to identify those compounds responsible for the characteristic odor as well as partly for the folk medicinal use of this plant. Especially sesqui- and monoterpenes were found to be dominating constituents of this essential oil, such as: β-caryophyllene, α-humulene, ishwarone, caryophyllene oxide I, ishwarol, ishwarane and aristolochene as well as linalool and α-terpinolene.The odor impression of the sample is described and the possible biological activity of some single volatiles shortly discussed. Full article

A derivative UV-spectrophotometric method was developed for the analysis of two halogenated 8-hydroxyquinoline derivatives; iodochlorohyroxyquin (I) (Clioquinol) and diiodohydroxyquin (II) (iodoquinol). The proposed method depends on the formation of Pd II-ligand complexes in methanol-acetonitrile mixture, which exhibits an UV-spectra with an appreciable value of ε. Zero order (⁰D), first order (¹D) and fourth order (⁴D) derivative measurements were applied for the quantitative analysis of the drugs. A linear correlation was established between absorbance and concentration for the ⁰D mode in the range 2-14µg ml^-1 and 2-18 µg ml^-1 for (I) and (II) with average % recoveries of 99.83 ± 1.04 and 99.9 ± 0.64 respectively. Also a linear correlation was obtained between the trough of the peak and concentration for ¹D mode in the range of 0.16-0.8 µgml^-1 for both dmgs with average % recoveries of 100.23 ± 1.04 and 100.18 ± 1.14 for (I) and (II) respectively. Besides, the ¹D mode was successfully applied for the analysis of binary mixture containing both (II) and metronidazole (III) in tablet formulations. The average % recoveries were 99.42 ± 0.358 and 98.81 ± 0.973 for (II) and (III) respectively. In the ⁴D mode, a linear correlation was attained between the amplitude of the peak and concentration in the range 0.1-0.8 µgml^-1 for (I) and (II), with average % recoveries of 99.6 ± 0.84 and 100.06 ± 0.98. The limit of detection (LOD) was 2.1 µg ml^-1 and 2.3 µg ml^-1 for (I) and (II) respectively. The suggested method was successfully applied for accurate, sensitive and selective analysis of the studied drugs in bulk and single or combined dosage forms with average % recoveries of 99.74 ± 0.480–99.84 ± 0.515 and 99.44 ± 0.71–100.58 ± 1.06 for (¹D) and (⁴D) respectively. The results obtained were favorably compared to those given by a reference method. Full article

The secondary metabolites in Lobaria pulmonaria and L. scrobiculata collected in northeast Anatolia are studied using HPLC. Constictic, nortictic and stictic acids are the major components in L. pulmonaria; in addition connorstictic, cryptostictic, and menegazziaic acids are present as minor constituents. In L. scrobiculata constictic, stictic, and usnic acids and m- scrobiculin are the major compounds; while cryptostictic and norstictic acids, and p- scrobiculin are present as minors. Full article

An accurate kinetic method for the determination of cisapride is described. The method is based on the reaction of cisapride with potassium dichromate in 2.5 M sulphuric acid at room temperature for a fixed-time of 10 min, afterwards the absorbance of the reaction product is measured at 527 nm. The concentration of cisapride is computed using the corresponding calibration equation for the fixed-time method. The method is applied successfully to commercial tablets and oral suspension dosage forms. The results obtained are compared statistically with the British Pharmacopoeia method. The determination of cisapride by other kinetic methods is feasible with calibration equation obtained but the fixed-time method proves to be more applicable. Full article

Two colorimetric and titrimetric procedures are developed for determination of some cephalosporins, namely, cefotaxime sodium (CFT), cehroxime sodium (CFU) and ceftazidime pentahydrate (CFZ). The first method, a colorimetric method, was based on the reaction of these cited drugs with 4-chloro-7-nitrobenzofurazan (NBD-Cl), in the presence of 5x10^-3 M borax, with the formation of stable colored chromogens with maximum absorbance in the range of 409 - 414 nm. All variables affecting the development of the colour have been investigated and the conditions were optimized. The method obeys Beer's law over concentration ranges of 19.09 - 95.49, 17.85 - 124.98 and 63.66 - 254.66 µg ml^-1 of CFT, CFU and CFZ, respectively. Obedience to Beer's law permitted the successful application of the proposed method for the assay of cefuran, cefumax and fortum vials. The results obtained reveal good percentage recoveries, which are in good agreement with those obtained by the official methods. In the second method, the titrimetric method, the conditions for the oxidimetric titration of cephalosporins have been studied. The titration takes place because of catalytic quantities of KBr, which give rise to an intermediate that can be hydrolyzed to the sulfoxide. The operating conditions are described and a hypothesis is put forward concerning the mechanism of the reaction. Full article

A simple and sensitive analytical method has been developed for the spectrophotometric assay of amlodipine besylate (ADB) in pure forms and tablets have been described. The method is based on the formation of a charge-transfer complex between the drug and tetrachloquinone (TCQ). This complex exhibit intense absorption bands in the electronic spectrum. The molecular ratio of the reactant in the complex was established and the experimental conditions leading to maximum charge-transfer band was also studied. The reaction proceeds quantitatively at pH 9 and 55°C for 10 min, the absorbance was measured at 346 nm. The method was applied to commercially available tablets and the results were statistically compared wrth those obtained by UV spectrophotometric method, using Newman-Keuls tests. In our method, Beer's Law limits to 5-25 µg/ml. The optimum experimental parameters for colour production with reagent were studied and incorporated into procedure. Full article

The construction of plasticised PVC matrix-type scopolamine ion- selective membrane electrode and its use in the potentiometric determination of scopolamine in pharmaceutical preparations are described. It is based on the use of tlie ion-associate species, fonned by scopolainine cation and 5-nitrobarbitoric counter ion. The basic electrode peifonnance characteristics are evaluated according to IUPAC I-ecoininendatioiis. It exhibited a linear response for 1x10^-2–1x10^-5 M of scopolamine solutions with a cationic Nernstian slope over the pH range of 4-7. Common organic and inorganic cations showed negligible interference. Direct potentiometric determination of 1x10^-2–1x10^-5 M aqueous tubocurarine chloride using this membrane electrode system showed an average recovery of 99.05 with a mean standard deviation of 0.12. This electrode system was successfully applied to the potentiometric determination of scopolamine in some pharmaceutical preparations. Full article