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RISS 인기검색어
- 검색키워드
- 저자 : Ahmed NabilA. (검색결과 4 건)
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Tadalafil oral disintegrating tablets: an approach to enhance tadalafil dissolution
Ahmed Refaat,Magda Sokar,Fatma Ismail,Nabila Boraei 한국약제학회 2015 Journal of Pharmaceutical Investigation Vol.45 No.5
Improvement of the dissolution behavior of poorly water soluble tadalafil using solid dispersion technique was investigated. Polyvinylpyrollidone (PVP) was used to prepare solid dispersions (SDs) based on different ratios; 1:1 (SD1,), 1:2 (SD2,), 1:3 (SD3), 1:4 (SD4,) respectively. Tadalafil/PVP/AvicelⓇ in a ratio of 1:2:2 respectively (SD5) was also prepared. SD5 was selected to formulate orally disintegrating tablets (ODTs). Five formulae were prepared (F1–F5) and characterized with respect to drug content uniformity, breaking strength, % friability, wetting behavior, oral disintegration time. Results revealed that SD2 exhibited the highest dissolution rate improvement, where mean dissolution time was 8.22 min compared to 60.12 min for free tadalafil. X-ray powder diffraction spectroscopy and differential scanning calorimetry showed partial drug amorphization in the tested SDs sample which was further confirmed by scanning electron microscope. Moreover, particle size analysis showed the presence of nanocrystals combined with microcrystals dispersed in the prepared SDs. Among the studied solid SDs, SD2 showed the most satisfactory results. In order to improve % yield of SD2 (70.14 %), avicel Ⓡ was added and the resulting tertiary combination (SD5) showed better flow and higher % yield value (94.22 %). % tadalfil released from SD2 & SD5 differ insignificantly (p ≥ 0.05). F3 (48 % mannitol, 16 % avicelⓇ, 16 % croscarmellose) showed superior wetting time (30.1 s), excellent oral disintegration time (20 s) with an accepted hardness (3.6 kg) & % friability (0.7). Additionally, F3 exhibited a significant improvement of tadalafil dissolution compared to that of pure drug and test commercial tablet brand (p B 0.05).
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Sweed Nabila M.,Fayez Ahmed M.,El-Emam Soad Z.,Dawoud Marwa H. S. 한국약제학회 2021 Journal of Pharmaceutical Investigation Vol.51 No.1
Purpose Rosuvastatin calcium (RSC) is a statin which, in addition to its anti-hypercholesteremic effects, was found to have a potential anticancer activity. The target of the present study is to develop self nano-emulsifying drug delivery systems (SNEDDS) loaded with RSC to overcome its poor solubility, and augment its anticancer activity. Methods A combined mixture-process experimental design was chosen for the optimization of SNEDDS by changing its mixture and process components, where the mixture components were the percentage of Smixture (surfactant and co-surfactant) ( X1) and the percentage of oil ( X2). The process components were the ratio of surfactant to co-surfactant ( X3), and the type of surfactant ( X4). Twenty-four formulae were evaluated for % transmittance and saturated solubility. Results The optimized formula ( O1) was selected based on the highest % transmittance and highest drug solubility, where the % transmittance was 99.05 ± 0.09% and the saturated solubility was 80.52 ± 2.57 mg/ml. The optimized formula has a globule size of 17.53 ± 0.89 nm, a zeta potential of − 10.2 ± 0.21 mV, and a cloud point of 88.5 ± 0.54 °C. Transmission electron microscopy demonstrated spherical droplet morphology. In vitro drug release showed remarkable increase in the drug release from the optimized formula as compared to the corresponding standard RSC. The anticancer activity of O1 was evaluated in HepG2 cell-line, where the IC50 value was 16.2 ± 0.23 μg/ml. The optimized formula increased cell death by both apoptosis and necrosis. Conclusion Our results show that the optimized SNEDDS formula is promising for enhancing the anticancer effect of RSC.
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Morimoto Keiki,Ahmed NabilA.,Lee Hyun-Woo,Nakaoka Mutsuo The Korean Institute of Electrical Engineers 2005 KIEE International Transactions on Electrical Mach Vol.b5 No.4
This paper presents two new circuit topologies of the dc busline side active resonant snubber assisted voltage source high frequency link soft switching PWM full-bridge dc-dc power converters acceptable for either utility ac 200V-rms or ac 400V-rms input grid. These high frequency switching dc-dc converters proposed in this paper are composed of a typical voltage source-fed full-bridge PWM inverter, high frequency transformer with center tap, high frequency diode rectifier with inductor input filter and dc busline side series switches with the aid of a dc busline parallel capacitive lossless snubber. All the active switches in the full-bridge arms as well as dc busline snubber can achieve ZCS turn-on and ZVS turn-off transition commutation with the aid of a transformer leakage inductive component and consequently the total switching power losses can be effectively reduced. So that, a high switching frequency operation of IGBTs in the voltage source full bridge inverter can be actually designed more than about 20 kHz. It is confirmed that the more the switching frequency of full-bridge soft switching inverter increases, the more soft switching PWM dc-dc converter with a high frequency transformer link has remarkable advantages for its power conversion efficiency and power density implementations as compared with the conventional hard switching PWM inverter type dc-dc power converter. The effectiveness of these new dc-dc power converter topologies can be proved to be more suitable for low voltage and large current dc-dc power supply as arc welding equipment from a practical point of view.
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Kourdali Sidali,Bounakous Nabila,Meknachi Abdellah,Zenati Bilal,Inal Ahmed 한국해양과학기술원 2020 Ocean science journal Vol.55 No.4
Biological monitoring has become one of the most widely used approaches in aquatic monitoring. As a result, the effect of the xenobiotics entrained by the organic and inorganic effluents on different aquatic species is therefore entirely distinct. The aim of this study is to assess and to compare changes in biological responses, as non-specified biomarkers, measured in the gills and adductor muscles of the Mediterranean and African mussels, Mytilus galloprovincialis (designated MG) and Perna perna (designated PP) coexisting on Algerian coastal sites (Figuier, W. Boumerdes, Algeria) during the Winter and Spring period (2015/2016). Catalase enzyme activity, total proteins, and condition index were measured in collected samples of two size classes (class1: [2–2.5 cm] and class2: [4.5–5.5 cm]). During the study period, the values of enzymatic activities were relatively higher in MG than in PP (January, class 2, MG: 46.9 U/mg proteins, PP: 39.1U/mg proteins). Additionally, the results obtained showed a slight disturbance of the metabolism in two species of the same size class which resulted in a remarkable increase of catalase activity in March (class 2, MG: 54.2 U/mg protein, PP: 49 U/mg protein) and in April (class 2, MG: 51.9 U/mg protein, PP: 44.8 U/mg protein) compared to the other months. During the study period, the total proteins revealed a variation nonspecific for the two species at various sizes. With regard to the results obtained, biological responses were completely different in the two species with various sizes that were exposed to the natural or anthropogenic changes. Seasonal specificity contributed considerably and differently to the stress of the two species. Moreover, the catalase enzyme activity and total proteins proved their effectiveness as nonspecific, relevant and sensitive biomarkers.
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