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  • Author: Gyéresi Árpád x
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Famous hungarian chemists and pharmacists – modern chemistry founders. Part I. 1.2. Lajos Winkler

Abstract

Pharmacist Winkler Lajos, PhD (1863-1939, born in Arad), professor at the University of Sciences from Budapest and member of the Hungarian Academy of Sciences, is considered the founder of modern analytical chemistry and drug analysis in Hungary.

He has developed and perfected a series of methods of volumetric and gravimetric analysis. Its original method, developed in 1888 for the determination of dissolved oxygen in water, is still used today.

Winkler Lajos also played an important role in the development of pharmaceutical education in Hungary

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Famous Hungarian chemists and pharmacists – modern chemistry founders: Károly Than

Abstract

Professor Károly Than was a very talented, widely travelled teacher, intuitive researcher, efficient organizer and public personality. His importance is beyond dispute in the development of Hungarian chemistry. Professor Béla Lengyel and other prominent individuals continued his scientific activity. Lot of honors, paintings, medals and reliefs also justify appreciation of his merits.

Open access
The Wnt Signalling Pathways: A Short Review and Specific Roles in Bone Biochemistry

Abstract

As musculoskeletal diseases become an emerging healthcare problem worldwide, profound and comprehensive research has been focused on the biochemistry of bone metabolism in the past decades. Wnt signalling, one of the novel described pathways influencing bone metabolism from the early stages of tissue development, has been recently in the centre of attention. Several Wnt ligands are implied in bone forming pathways via canonical (β-catenin dependent) and non-canonical (β-catenin independent) signalling. Osteoporosis, a catabolic bone disease, has its pathologic background related, inter alia, to alterations in the Wnt signalling, thus key modulators of these pathways became one of the most promising targets in the treatment of osteoporosis. Antibodies inhibiting the activity of endogenous Wnt pathway inhibitors (sclerostin, dickkopf) are recently under clinical trials. The current article offers a brief review of the Wnt signalling pathways, its implication in bone metabolism and fate, and the therapeutic possibilities of osteoporosis through Wnt signalling.

Open access
Preparation and investigation of mefenamic acid – polyethylene glycol – sucrose ester solid dispersions

Abstract

Mefenamic acid (MA) is a widely used non-steroidal antiinflammatory (NSAID) drug. The adverse effects typical of NSAIDs are also present in the case of MA, partly due to its low water solubility. The aim of this study was to increase the water solubility of MA in order to influence its absorption and bioavailability. Solid dispersions of MA were prepared by the melting method using polyethylene glycol 6000 and different types (laurate, D-1216; palmitate, P-1670; stearate, S-1670) and amounts of sucrose esters as carriers. The X-ray diffraction results show that MA crystals were not present in the products. Dissolution tests carried out in artificial intestinal juice showed that the product containing 10 % D-1216 increased water solubility about 3 times. The apparent permeability coefficient of MA across human Caco-2 intestinal epithelial cell layers was high and, despite the difference in solubility, there was no further increase in drug penetration in the presence of the applied additives.

Open access
Development and Validation of an UV-Spectrophotometric Method for the Assay of Strontium Ranelate and HPLC Stability Testing from Bulk and Pharmaceutical Dosage Form

Abstract

Objective: The present work offers a fast, reliable and easy UV spectrophotometric method for the assay of strontium ranelate from bulk samples and pharmaceutical dosage form.

Methods: The proposed method uses 0.1% V/V trichloroacetic acid as dissolution medium for spectrophotometric analysis, by signal detection at 321 nm. The method was validated according to the currently in-force international guidelines for linearity, accuracy, precision, robustness, limit of detection and quantification.

Results: The method was found to be linear in the range of 5-100 µg mL-1 (R2 > 0.999). Method accuracy was found in-between 98.87-100.41%, showing good linear correlation as well (R2 = 0.9997). The concentrations for limit of detection and limit of quantitation were found 1.13 µg mL-1 and 3.77 µg mL-1, resp. The proposed method showed good intra- and interday precision, with low RSD values of 0.53-1.24% and 1.11%, resp.

Conclusions: Stability studies performed by both HPLC and UV spectrophotometric methods revealed that the active substance is highly susceptible to acidic hydrolysis, oxidation and exposure to high temperature.

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Reversed phase HPLC for strontium ranelate: Method development and validation applying experimental design

Abstract

A reverse-phase HPLC (RP-HPLC) method was developed for strontium ranelate using a full factorial, screening experimental design. The analytical procedure was validated according to international guidelines for linearity, selectivity, sensitivity, accuracy and precision. A separate experimental design was used to demonstrate the robustness of the method. Strontium ranelate was eluted at 4.4 minutes and showed no interference with the excipients used in the formulation, at 321 nm. The method is linear in the range of 20–320 μg mL−1 (R2 = 0.99998). Recovery, tested in the range of 40–120 μg mL−1, was found to be 96.1–102.1 %. Intra-day and intermediate precision RSDs ranged from 1.0–1.4 and 1.2–1.4 %, resp. The limit of detection and limit of quantitation were 0.06 and 0.20 μg mL−1, resp. The proposed technique is fast, cost-effective, reliable and reproducible, and is proposed for the routine analysis of strontium ranelate.

Open access