Bitterness evaluation of medicines for pediatric use by a taste sensor.
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The purpose of this study was to evaluate the bitterness of 18 different antibiotic and antiviral drug formulations, widely used to treat infectious diseases in children and infants, in human gustatory sensation tests and using an artificial taste sensor. Seven of the formulations were found to have a bitterness intensity exceeding 1.0 in gustatory sensation tests (evaluated against quinine as a standard) and were therefore assumed to have an unpleasant taste to children. The bitterness intensity scores of the medicines were examined using suspensions in water or an acidic sports drink. In the case of three macrolide antibiotic formulations containing erythromycin (ERYTHROCIN dry syrup), clarithromycin (CLARITH dry syrup for pediatric), and azithromycin (ZITHROMAC fine granules for pediatric use), the bitterness intensities of suspensions in acidic sports drinks were dramatically enhanced compared with the corresponding scores of suspensions in water. This enhancement could be predicted using the taste sensor. On the other hand, a reduction of bitterness intensity was observed for an acidic sports drink suspension of an amantadine product (SYMMETREL fine granules) compared with an aqueous suspension. This reduction in bitterness could also be predicted using the taste sensor output value. Thus, the taste sensor could predict whether or not suspension in an acidic sports drink would enhance or reduce the bitterness intensity of pediatric drug formulations, compared with suspensions in water. (+info)
Quality assessment of morphine hydrochloride solutions.
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The therapeutic substances in solution prepared in pharmaceutical laboratories (prescribed drugs) must preserve their activity. Therefore, they must be stable throughout the period of storage in home conditions. The maintenance of stability is particularly difficult for morphine hydrochloride solutions administered orally to cancer patients at the last stage of the disease being at home. This study, aiming at the assessment of stability of morphine hydrochloride solutions, was performed on samples of 0.5% water solutions of the drug alone, 0.25% and 0.5% solutions of the drug in water with chloroform as well as injection solutions (Morphinum hydrochloricum, 20 mg, Polfa Warsaw). All the samples were kept at 20 degrees C for six months. Throughout this time observations were made to detect changes in their appearence and pH values. Their qualitative composition was determined by TLC and the content of morphine was checked by UV spectrophotometry in an environment of 0.1 mol/l of hydrochloric acid at 285 nm. Results of the kinetic study permitted drawing conclusions as to the mechanism of the decomposition of morphine hydrochloride in the solutions studied - according to a simple first order reaction and determination of the rate constants (k, s(-1)) of the process. Results of the chromatographic and spectrophotometric study did not show differences in the stability of water and chloroform/water solutions of morphine hydrochloride studied after 4 weeks and 6 months. After that time the decrease of morphine content was 10 and 25%, respectively. (+info)
Analysis of phthalate contamination in infusion solutions by automated on-line in-tube solid-phase microextraction coupled with high-performance liquid chromatography.
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Contamination of infusion solutions with phthalates was analyzed, and its origin was determined. Phthalates were determined by on-line in-tube solid-phase microextraction coupled with high-performance liquid chromatography (in-tube SPME-HPLC) with UV detection. In-tube SPME is an extraction technique for organic compounds in aqueous samples, in which analytes are extracted from the sample directly into an open tubular capillary by repeated draw/eject cycles of sample solution. The infusion solutions were used without any pretreatment, and the phthalates in these solutions were automatically analyzed by the on-line in-tube SPME-HPLC system. The limits of detection of phthalates in the infusion solutions were 1-10 ng/mL. With a few exceptions, the recoveries of phthalates added to the infusion solutions were above 80%. Di-n-butyl phthalate (DBP) was detected at a concentration of 7-60 ng/mL in most infusion solutions in plastic containers but was not detected in those in glass bottles. On the other hand, no other phthalates were detected in infusion solutions in either plastic or glass containers. Large amounts of DBP were detected in the adhesive used to affix the paper labels to the plastic bottles and bags, but not in the plastic containers themselves. Furthermore, DBP was shown to be readily eluted from the adhesive into water and alcohol and easily pass through the plastic. These results indicated that the source of the DBP was the adhesive used to affix the paper labels, and DBP contaminated the infusion solutions by passing through the plastic. The in-tube SPME-HPLC method is simple and rapid and provides a useful tool for the screening and determination of phthalate contamination in infusion solutions. (+info)
Rifampicin inhibits alpha-synuclein fibrillation and disaggregates fibrils.
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The aggregation of alpha-synuclein in dopaminergic neurons of the substantia nigra is a critical step in the pathogenesis of Parkinson's disease. We show that the antibiotic rifampicin inhibited alpha-synuclein fibrillation and disaggregated existing fibrils in a concentration-dependent manner. Size-exclusion chromatography data indicated that rifampicin stabilized alpha-synuclein as both a monomer and soluble oligomers comprised of partially folded alpha-synuclein. Experiments using aged samples of rifampicin indicated that the most active species in inhibiting fibrillation and disaggregating fibrils is an oxidation product of rifampicin, which was confirmed in experiments under anaerobic conditions. These results indicate that rifampicin-mediated inhibition of alpha-synuclein fibrillation and disaggregation of fibrils involves preferential stabilization of monomeric and soluble oligomeric forms, and that rifampicin potentially may have therapeutic application for Parkinson's disease. (+info)
Validation of electrochemical determination of zinc in selected pharmaceutical preparations.
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A procedure of voltammetric (DP) determination of zinc in two selected pharmaceutical preparations was validated. The source of zinc in the first of them (Bio-Cynk) was the organic salt-gluconate, while the second (Zincteral) contained zinc sulfate. In order to transform zinc into solution, the samples of powdered tablets of each preparation underwent the extraction or mineralisation procedure. The concentration of zinc in solution was determined by differential pulse voltammetry (DP). In the validation process, the selectivity, accuracy, precision and linearity of DP determination of zinc in both preparations were examined. Zinc was determined within the concentration range of 1-20 ppm: the mean recoveries approached 98% in the case of Bio-Cynk and 100% for Zincteral; the errors of determination (RDS) were 2.98-11.5% for Bio-Cynk and 3.06-5.32% for Zincteral, respectively. (+info)
The chromatographic data in QSAR assay of TIQs derivatives with beta2-adrenergic activity.
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We performed QSAR analysis of beta2-adrenergic activity and chromatographic data of 4,6,8-trihydroxy-, 6,7-dihydroxy- and 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives. TLC plates (silica gel NP 60F(254) and silica gel RP2 60F(254) silanised precoated), impregnated with solutions of analogues of the selected amino acids were used as beta2-agonistic and antagonistic interaction models. QSAR analysis of the beta2-adrenergic activity and the chromatographic data of the solutes were made. A correlation between biological data and behaviour of the examined compounds in a chromatographic modifiable environment (S1-S3) was investigated by the linear regression analysis method. (+info)
Comparison of classical and derivative UV-spectrophotometric methods for the quantification of diltiazem and mexiletine.
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A first order derivative UV-spectrophotometric method for the determination of diltiazem hydrochloride and mexiletine hydrochloride has been developed and validated. In the assay, the first- and second-order measurements with the use of the "peak-zero" and "peak-peak" techniques were applied. The linear correlation (r < 0.9999) between the amplitude of the peak and the concentration of the examined drugs in the range of 3.0-8.0 microg mL(-1) for diltiazem and 50-100 microg mL(-1) for mexiletine was obtained. The proposed method was successfully applied for accurate (mean recovery about 100%), precise (RSD about 1%) and selective determination of the studied drug in the pure and dosage forms. (+info)
Use of a systematic risk analysis method to improve safety in the production of paediatric parenteral nutrition solutions.
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BACKGROUND: Until recently, the preparation of paediatric parenteral nutrition formulations in our institution included re-transcription and manual compounding of the mixture. Although no significant clinical problems have occurred, re-engineering of this high risk activity was undertaken to improve its safety. Several changes have been implemented including new prescription software, direct recording on a server, automatic printing of the labels, and creation of a file used to pilot a BAXA MM 12 automatic compounder. The objectives of this study were to compare the risks associated with the old and new processes, to quantify the improved safety with the new process, and to identify the major residual risks. METHODS: A failure modes, effects, and criticality analysis (FMECA) was performed by a multidisciplinary team. A cause-effect diagram was built, the failure modes were defined, and the criticality index (CI) was determined for each of them on the basis of the likelihood of occurrence, the severity of the potential effect, and the detection probability. The CIs for each failure mode were compared for the old and new processes and the risk reduction was quantified. RESULTS: The sum of the CIs of all 18 identified failure modes was 3415 for the old process and 1397 for the new (reduction of 59%). The new process reduced the CIs of the different failure modes by a mean factor of 7. The CI was smaller with the new process for 15 failure modes, unchanged for two, and slightly increased for one. The greatest reduction (by a factor of 36) concerned re-transcription errors, followed by readability problems (by a factor of 30) and chemical cross contamination (by a factor of 10). The most critical steps in the new process were labelling mistakes (CI 315, maximum 810), failure to detect a dosage or product mistake (CI 288), failure to detect a typing error during the prescription (CI 175), and microbial contamination (CI 126). CONCLUSIONS: Modification of the process resulted in a significant risk reduction as shown by risk analysis. Residual failure opportunities were also quantified, allowing additional actions to be taken to reduce the risk of labelling mistakes. This study illustrates the usefulness of prospective risk analysis methods in healthcare processes. More systematic use of risk analysis is needed to guide continuous safety improvement of high risk activities. (+info)