Judul: Mikroenkapsulasi Ibuprofen Menggunakan Paduan Lilin Lebah-Pektin dengan Tween 20 sebagai Pengemulsi
Abstrak: Penggunaan ibuprofen dalam jangka panjang dapat menyebabkan efek samping antara lain tukak lambung dan pendarahan pada gastrointestinal. Salah satu cara menanganinya adalah dengan mengenkapsulasi ibuprofen sehingga pelepasannya dapat diperlambat. Penelitian ini bertujuan mengenkapsulasi ibuprofen menggunakan paduan lilin lebah-pektin dengan Tween 20 sebagai pengemulsi. Metode yang digunakan adalah emulsi penguapan pelarut dengan pelarut diklorometana. Rendemen dan efisiensi enkapsulasi teringgi berturut-turut adalah 70% dan 72% didapatkan pada mikrokapsul dengan nisbah lilin lebahpektin 6:4 dan konsentrasi Tween 20 sebesar 1%. Profil disolusi menunjukkan bahwa ibuprofen terlepas secara lambat dari mikrokapsul dengan persen pelepasan 36% setelah 6 jam. Hasil pengamatan morfologi menunjukkan bahwa mikrokapsul memiliki permukaan tidak halus dengan tonjolan-tonjolan yang tidak beraturan. Spektrum inframerah menunjukkan bahwa interaksi yang terbentuk pada mikrokapsul merupakan interaksi fisik.
Keyword: xdisolusi, efisiensi, ibuprofen, mikrokapsul

Judul: Optimasi dan Evaluasi Mikrokapsul Ibuprofen Tersalut Lilin Lebah
Abstrak: Ibuprofen is a non-steroid anti-inflammatory drug for treating rheumatoid arthritis. It has a short biological half-life and can impose gastrointestinal irritation, so that a controlled drug release system is required, one of which is by microencapsulation technique. In this research, microencapsulation of ibuprofen was done by emulsion-solvent evaporation method. Variation of ibuprofen:beeswax ratio (1:1, 1:2, and 1:3) and concentration of gelatine emulsifier (1, 1.5, 2, and 2.5%) were tested to obtain optimum microcapsule. The yield of microencapsulation were varied from 77.17 to 88.84%. The highest encapsulation efficiency of ibuprofen was 93.78%, obtained in microcapsule with beeswax-ibuprofen ratio 1:1 and gelatine concentration 2%. Variation concentration of gelatine significantly influenced the encapsulation efficiency at ratio 1:3. Microcapsule with the highest encapsulation efficiency released 38.22% of ibuprofen in gastric fluid simulation medium for 6 hours. The kinetics of ibuprofen release followed Korsmeyer-Peppas model. The microcapsule particles size ranged from 200 to 250 μm. Based of these results, it was concluded that microencapsulation of ibuprofen with beeswax can maintain the release rate of drug in intestine.
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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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