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: Pelepasan Ibuprofen dari Mikrokapsul Tersalut Paduan Lilin Lebah dan Poli(asam laktat) Secara In Vitro
Abstrak: Ibuprofen as an anti-inflammatory drug has a short elimination rate which can causes gastric irritation. Microencapsulation technique can be used to overcome these problems and provide a better therapeutic efficacy through controlled drug release mechanism. In this research, microencapsulation of ibuprofen carried out by blending process and emulsion-solvent evaporation method. Ibuprofen was coated by blend beeswax and poly(lactic acid) (PLA) with various compositions (9:1, 8:2, 7:3, and 6:4) and concentration of gelatin (1%, 1.5%, and 2%) as an emulsifier. Efficiency of encapsulation performed in simulated intestinal medium pH 7.2. The highest value of ibuprofen encapsulation efficiencies was equal to 84.21% had been produced by microcapsules with ratio bees wax:PLA 6:4 and concentration of gelatin 2%. Release test of ibuprofen was performed by beeswax:PLA blend with ratio 8:2 and 6:4 produces the highest average percentage release about 15.31% and 19.25% at minute 225 in the same medium. The release pattern of ibuprofen had followed zero order kinetics model explaining that concentration of ibuprofen released relative constant for each release time. Observation of surface morphology of microcapsules using a scanning electron microscop (SEM) showed subtle bulges irregularly shaped scattered on its surface.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular