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Belgrade, Serbia

Maric L.B.,Galenika Ad | Jovic B.D.,University of Novi Sad | Petrovic S.D.,University of Belgrade | Nikolic A.M.,University of Novi Sad | Homsek I.J.,Galenika Ad
Journal of the Serbian Chemical Society | Year: 2014

This paper reports the use of near infrared (NIR) spectroscopy as a process analytical technology (PAT) tool for monitoring the metformin (N,N- -dimethylimidodicarbonimidic diamide) hydrochloride and poly(vinyl pyrrolidone) (PVP) mixing process, which is the first stage in tablet production. Blend homogeneity was tested using the non-invasive NIR spectroscopy method and the partial least squares (PLS) regression model was applied for the analysis of the obtained spectra. Simultaneously, the critical parameter (metformin hydrochloride content) was monitored by a classical analytical technique, the validated HPLC method, commonly used for this purpose. Based on the high sensitivity of the model developed in this study, as well as the established correlation among the results obtained by different methods, it could be concluded that the proposed rapid and non-invasive technique could be an effecttive tool for the monitoring of one of the critical manufacturing steps in the production solid dosage forms. © 2014 Copyright SCS. Source


Alginate hydrogels are widely used in biomedicine due to alginate availability, hydrophilic nature, biocompatibility and biodegradability. Alginate microbeads are particularly attractive for applications in pharmacy and regenerative medicine due to high surface to volume ratio, low mass transfer limitations and simple implantation by injection. Aim of this work was to investigate possibilities for controlled degradation of alginate microbeads in cell culture medium (Dulbeccós modified Eaglés medium) with Na-citrate added in small concentrations (0.05-0.5 mM). Alginate microbeads (1.5% w/w, 800 μm in diameter) were produced by electrostatic droplet extrusion and evaluated over a period of 10 days regarding appearance, kinetics and degree of swelling as well as biomechanical properties determined in a novel bioreactor with mechanical stimulation under in vivo-like conditions in articular cartilage (10% strain, 337.5 μm/s compression rate). In the citrate concentration range investigated, microbeads initially swelled reaching an equilibrium value (∼150-170% with respect to the initial mass), upon which they appeared stable for a certain period of time (1 to over 7 days) followed by bead bursting and degradation. This degradation process indicated that Na+ from the solution initially replaced Ca2+ bound mainly to COO- groups in polymannuronate sequences inducing electrostatic repulsion of polymer chains and, consequently, swelling of the beads. Citrate ions assisted in this process by forming insoluble calcium citrate. Thus, the specific rate of the bead swelling increased with the increase in citrate concentration approaching a maximal value of ∼0.34 d-1. In the last phase, the beads burst into pieces, which slowly continued to degrade by replacement of Ca2+ bonded to polyguluronate blocks in the egg-box structure. Compression moduli for packed beds of control, freshly produced microbeads, and microbeads swelled at the equilibrium degree after 3 days of staying in 0.2 mM Na-citrate solution were 136.6±2.8 and 30.8±1.3 kPa, respectively. By day 7 in this solution, the beads still appearing structurally intact, further lost their mechanical strength due to continued polymer chain relaxation so that the compression modulus was 20.7 to 22.6 kPa owed almost solely to undegraded polyguluronate parts. Results of these studies are important from a fundamental standpoint for determination of structure and degradation mechanisms of alginate hydrogels but also from a practical point of view for optimization of hydrogel properties and behavior for potential applications in controlled drug release as well as in tissue engineering. Source


Djukic-Cosic D.,Farmaceutski fakultet Univerziteta u Beogradu | Stanojevic A.,Galenika Ad | Djekic-Ivankovic M.,Institute za medicinska istrazivanja | Curcic M.,Farmaceutski fakultet Univerziteta u Beogradu | And 3 more authors.
Vojnosanitetski Pregled | Year: 2011

Background/Aim. The beneficial effects of medicinal plants are well-known from the ancient times. However, expansion of phytopharmacy and phytotherapy occured during the last decades. Medicinal plants can absorb environmental contaminants from the ground and consequently may cause harmful effects on human health. Quality control usually comprises standard methodology which includes macroscopic identification and examination of active ingredients. Additionaly, there is a permanent need to control the level of pollutants in herbs, with a particular attention to the level of toxic metals. In this study we estimated the level of contamination by determining the content of cadmium (Cd) in the herbs of Hypericum perforatum and Thymus serpyllum collected from the different localities of the mountains Rtanj and Ozren. Methods. Herbs of investigated plants were collected during July 2005 from various localities of Rtanj and Ozren mountains. After drying, homogenization and mineralization, Cd content was determined by atomic absorption spectrophotometry. Results. The obtained results show that Cd content varies significantly in Hypericum perforatum samples collected. The lowest Cd level was found in samples from the one of Rtanj localities (0.25 mg Cd/kg), while the highest was observed in Hypericum perforatum from Ozren locality (1.24 mg/kg). Levels of Cd in the three of four investigated localities were higher than proposed by WHO (0.3 mg/kg dried herb material). In all investigated samples of Thymus serpyllum herbs Cd levels were below the limit of detection of analytical method (0.2 mg Cd/kg dried materials). Conclusion. This work contributes to the issue of Cd content in Hypericum perforatum and Thymus serpyllum grown in localities of Rtanj and Ozren, and implies the importance for systemic control of Cd content in Hypericum species in order to provide safety of their preparations. Furthermore, regarding Cd toxicity, maximal permissible level of Cd in plant material should be evaluated and established concerning national legislative frame. Source


In this study, we collected and analyzed information on the importance of drug packaging quality to end users and pharmaceutical industry, as an indicator of the process of traceability and originality of drugs. Two surveys were conducted: one among the end users of drugs (252 patients) and the other among professionals working in seven pharmaceutical companies in Serbia. For most end users (82.5%), the quality of the packaging was important, but only 41.8% of them thought that the appearance of the packaging could be an indicator of genuinity of drugs. The existence of the control marks (KM) on drug packaging was not of great importance, since most of the users (86.9%) know its function, but the majority (60.2%) would nevertheless decide to buy the drug without KM. Regarding the experts from the pharmaceutical industry, more then two thirds (68.4%) believed that the existance of KM did not contribute to efficient operations. Although a great number of pharmaceutical industry professionals (84.2%) answered that the introduction of GS1 DataMatrix system would allow for complete traceability of the drug from the manufacturer to the end user, only 22.2% of them introduced this system to their products. This study also showed that domestic producers did not have a great interest for additional protection (special inks, holograms, special graphics, smart multicolor design, watermark, chemically labeled paper and cardboard, etc.) on their products, given that only 15.8% of them had some kind of additional protection against counterfeiting. Monitoring drug traceability from a manufacturer to end user is achieved by many complex activities regulated by law. A high percentage of responders said they were satisfied with the functionality of traceability systems used in their companies. As a way to increase the quality of drug packaging and business performance, most responders saw in the continuous improvement of the system of traceability within the company's overall quality management system. For them, a big financial investment in the complete traceability chain was not feasible because of the inability to achieve competitive prices in the market. Since only three of the surveyed companies were part of international chains, these findings open the path for new research that would include more multinational drug manufacturers from the region, in order to fully comprehend the importance of investing in the drug chain traceability and protection against counterfeiting, as a part of total quality management process in the pharmaceutical industry. Source


Pjanovic R.,University of Belgrade | Bo.skovic-Vragolovic N.,University of Belgrade | Veljkovic-Giga J.,Galenika Ad | Garic-Grulovic R.,University of Belgrade | And 2 more authors.
Journal of Chemical Technology and Biotechnology | Year: 2010

BACKGROUND: The mass transfer of model drugs Lidocaine hydrochloride and Dihydroquercetin from hydrogels (the usual carriers for topical drugs), and hydrogels containing liposomes, as novel drug vehicles,was studied. Diffusion experiments were performed using a Franz diffusion cell. Experimental data were used to calculate drug diffusion coefficients acrossmembranes, and their effective diffusion coefficients from hydrogels and liposome containing hydrogels. For the first time the diffusion resistance of all drug carriers was determined from corresponding diffusion coefficients. The main aim of this work was the study of drug diffusion coefficients from liposomes and their comparison with related diffusion coefficients from hydrogels to find how liposomes contribute to prolonged and controlled drug release. RESULTS: Drug diffusion coefficients were: 1.38 • 10-8m2 s-1 for Lidocaine hydrochloride and 5.96 • 10-9m2 s -1 for Dihydroquercetin, while corresponding effective diffusion coefficients from hydrogels were: 7.82 • 10-10m2 s-1 and 7.98 • 10-10m2 s-1, respectively. Effective diffusion coefficients from liposome-containing hydrogels were:4.82 • 10-10m2 s-1 (Lidocaine hydrochloride) and 4.305 • 10-10m2 s -1 (Dihydroquercetin). Diffusion resistances for the two hydrogels were almost the same. Very similar values of diffusion resistances for all liposome dispersions were obtained. CONCLUSION: Calculated diffusion coefficients and resistances demonstrate that liposomes, as drug carriers, significantly affect diffusion rates. The results obtained could be used whenever diffusion-controlled drug release is required. © 2010 Society of Chemical Industry. Source

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