Judul: Nanoenkapsulasi ketoprofen tersalut kitosan-alginat berdasarkan jenis dan ragam konsentrasi surfaktan
Abstrak: Dalam penelitian ini dilakukan nanoenkapsulasi ketoprofen tersalut kitosan-alginat dengan mengevaluasi pengaruh jenis dan konsentrasi surfaktan. Ragam dilakukan dengan waktu sonikasi (15, 30, dan 60 menit) serta konsentrasi surfaktan (1, 2, dan 3%) Tween 80 (polietilena sorbitan monooleat) dan Span 80 (sorbitan monooleat). Hasilnya memperlihatkan bahwa efisiensi enkapsulasi terbesar (51.2-52.3%) diperoleh dalam kurun waktu sonikasi 29-53 menit dengan konsentrasi Tween 80 1.3-2.3%. Efisiensi enkapsulasi terbesar yang menggunakan Span 80 sebesar 49.3-50.8% terjadi dalam rentang konsentrasi Span 80 2.26-3% dan waktu sonikasi 15-18 menit. Jumlah kapsul berukuran 10-1000 nm yang dihasilkan pada surfaktan Tween 80 dan Span 80 berturutturut sebesar 34.7-36.3% dan 30.1-31.3%. Kapsul tersebut diperoleh pada waktu sonikasi dan konsentrasi surfaktan yang sama (60 menit dan 3%).
Keyword: Crustaceae, Ultrasonic probe, Ketoprofen

Judul: Perilaku Disolusi Mikrokapsul Ketoprofen Tersalut Gel Kitosan-Alginat Berdasarkan Ragam Konsentrasi Tween 80
Abstrak: Chitosan ability to form gel has been extensively studied and modified; natural hydrocoloid addition is just an example. Chitosan-alginate gel has a promising potential to be applied as a good coating material in drugs delivery system. In this study, chitosanalginate gel coated ketoprofen microcapsules were made using spray drying method. Tween 80 solution concentration used in the process was varied (1, 2, and 3% (v/v)). The resulting microcapsules particle sizes were ranging from 150 nm to 6 μm. The dissolution test results showed that the Tween 80 solution concentrations were affecting ketoprofen releasing rate for the microcapsule. Maximum ketoprofen release rates either in acidic or basic medium were observed at 2% Tween 80 concentration. The maximum released ketoprofen amounts in acidic and basic medium were 35.19 and 287.92 ppm, respectively. The releasing mechanism was determined by evaluating the releasing kinetic models. The ketoprofen releasing kinetic model, both in acidic and basic medium, was following the Hixson-Crowell kinetic model.
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Judul: Analysis of Unequal Income Distribution with Cobb-Douglas Production Function
Abstrak: This paper studies the economic growth model by Moav (2002). Moav model shows the existence of unequal income distribution between low-income with high-income community. That kind of unequal income distribution is caused by uneven distribution of income. On this Moav model, there is one area called the threshold. Threshold becomes a benchmark to determining whether a society is categorized into low- or high- income community. The production function used in this paper is the Cobb-Douglas function. The dynamics of this model is described as difference equation of low-income, threshold, and high-income community. Simulation study on the model is carried out using Maple 13 and Mathematica 7.0 software. Overall, from the observed case, high-income community will reach a stable condition earlier, followed by the threshold, and then the low-income community.
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