Judul: Perilaku Disolusi Ketoprofen Tersalut Gel Kitosan-Gom Guar
Abstrak: Kemampuan kitosan untuk membentuk gel telah banyak dimodifikasi, salah satunya dengan penambahan hidrokoloid alami. Gel kitosan-gom guar berpotensi sebagai penyalut untuk digunakan dalam sistem pengantaran obat. Dalam penelitian ini, gel kitosan-gom guar digunakan untuk mempelajari perilaku disolusi ketoprofen. Mikrokapsul ketoprofen tersalut gel kitosan-gom guar dibuat dengan metode pengeringan semprot. Sebanyak 228.60 ml larutan kitosan 1.75% (b/v) dicampurkan dengan 38.10 ml larutan gom guar dengan ragam konsentrasi 0.35, 0.55, dan 0.75% (b/v), 7.62 ml glutaraldehida dengan ragam konsentrasi 3.0, 3.5, dan 4.0% (v/v), 2 g ketoprofen yang dilarutkan di dalam etanol 96%. Campuran homogen yang diperoleh kemudian dimasukkan ke dalam alat pengering semprot dan dihasilkan butiran/granul sebagai produk. Mikrokapsul yang optimum ditentukan dengan metode respons permukaan dalam peranti lunak Minitab Release 14 dan kemudian dikaji perilaku disolusinya. Uji disolusi dilakukan pada suhu (37 ± 0.5) °C dengan laju pemutaran 150 rpm selama 90 menit dalam medium disolusi bufer klorida pH 1.2 (cairan lambung) dan bufer fosfat pH 7.4 (cairan usus). Aliquot diambil setelah disolusi berlangsung 15, 30, 45, 60, 75, dan 90 menit. Serapan ketoprofen dalam alikuot diukur pada panjang gelombang 258 nm (untuk cairan lambung) dan 260 (untuk cairan usus). Mikrokapsul optimum diperoleh saat konsentrasi gom guar dan glutaraldehida berturut-turut 0.35% (b/v) dan 3.75% (v/v) untuk konsentrasi kitosan 1.75%. Kondisi ini dapat digunakan untuk menyalut ketoprofen sebanyak 146.5086 mg. Hasil uji disolusi ketoprofen menunjukkan kinetika reaksi orde ke-3 dengan nilai tetapan laju pelepasan ketoprofen, k dan waktu paruh, t1/2 rerata berturut-turut 1×10-5 l2mol-2menit-1 dan 15 menit.
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Judul: Perilaku Disolusi Ketoprofen Tersalut Rangkap dalam Gel Kitosan-Gom Guar dengan Alginat.
Abstrak: Modification of chitosan gel by guar gum hydrocoloid with glutaraldehyde cross-link is capable to coat drug as microcapsule. The release rate in gastric medium and intestinal has been studied by dissolution test. Dissolution result of chitosan-gum guar coated ketoprofen previously showed that the microcapsule shaterred at gastric pH so that the drug release was not restrained. Double coating of ketoprofen by chitosan-gum guar with alginate in order to improve ketoprofen release has been done in this research. A number of concentration levels of alginate and CaCl2 solutions were applied for optimation of coat performance. Test dissolution result of ketoprofen showed time effect to ketoprofen release through kinetic models of drugs release. In acid medium, a large part of coating formulas followed Korsmeyer-Peppas model, while all coating formulas followed Korsmeyer-Peppas model in alkaline medium. The mechanism of drugs release in this research is diffusion.
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Judul: Mitochondrial DNA Gene Organization and Phylogenetic Relationship of Naja siamensis
Abstrak: Naja siamensis is one of Asiatic cobra in the Family of Elapidae, known as a cryptic snake. It has many morphological variations that lead to misidentification. Misidentification can cause the wrong concept in developing antivenom types due to high snakebite cases occur in Thailand. Thus, an accurate species identification using a molecular approach is crucially required. Mitochondrial DNA has been used widely in snake molecular studies. These studies were aimed to determine the arrangement of the N. siamensis partial mitochondrial genes using reptile-oriented primers and to reveal the phylogenetic relationship among other species of Asian cobra. DNA extraction was carried out based on the standard DNA salting-out protocol and was conducted by bioinformatics analysis using BLASTn and MEGA 6 software. Gene annotation was performed against N. kaouthia complete genome. A total of 3121 bp of N. siamensis mtDNA genes were sequenced consisting of partial of six regions: 16S rRNA, ND1, tRNA-Ile, CRII region, tRNA-Leu, tRNA-Gln, and COI genes. The mtDNA gene organization of N. siamensis was predicted to has a similar pattern with the common Elapidae mtDNA gene organization. This study showed that there is a monophyletic form in Naja genus and N. kaouthia is the closest species with N. siamensis based on partial 16S rRNA and ND1 gene.
Keyword: 16S rRNA, Elapidae, ND1, phylogenetic relationship