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"Penelitian ini bertujuan untuk mempertahankan aktivitas antiplatelet bromelain sebagai hasil isolasi dari degradasi di lingkungan lambung dengan merangkumnya dalam matriks hidrogel gum chitosan-guar yang dihubungkan silang dengan glutaraldehyde untuk memastikan pelepasan obat yang ditargetkan pada lingkungan usus. Isolasi bromelain enzim dari batang nanas dilakukan melalui beberapa langkah yaitu ekstraksi, fraksinasi dengan ammonium sulfat, dan dialisis. Aktivitas spesifik masing-masing fraksi menunjukkan peningkatan, dari enzim kasar (43,73 U/mg), fraksinasi dengan ammonium sulfat (369,01 U/mg), dan dialisis (437,89 U/mg). Enzim bromelain yang dihasilkan dari dialisis kemudian dienkapsulasi dalam matriks hidrogel dengan cara post-loading untuk diuji untuk disolusi in vitro di lingkungan buatan dan usus. Hidrogel yang digunakan adalah chitosan-guar gum dengan 3% (v/v) konsentrasi glutaraldehyde, dengan rasio pembengkakan masing-masing 75,83% dan 68,39% pada pH 1,2 dan 7,4. Konsentrasi bromelain yang diisolasi bervariasi pada setiap proses enkapsulasi yang masing-masing 20 mg/L, 40 mg/L, dan 60 mg/L sehingga efisiensi enkapsulasi optimal sebesar 93,72% diperoleh pada 20 mg / L. Hasil uji disolusi menunjukkan pelepasan bromelain maksimum yang relatif tinggi di lingkungan usus buatan (73,53%) dibandingkan dengan lingkungan stomatch (19,11%) dengan aktivitas proteolitik maksimum masing-masing 0,43 U/mL dan 0,18 U/mL di usus buatan dan lingkungan lambung. Hasil disolusi kemudian dimasukkan ke dalam model matematika persamaan zeroth, orde pertama, Higuchi, dan persamaan Korsmeyer-Peppas untuk menentukan mekanisme disolusi obat dengan difusi Fickian. Uji antiplatelet menunjukkan persentase penghambatan yang baik terhadap enzim dialisis (46,60%) dan larutan disolusi (41,31%).

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This study aims to maintain the antiplatelet activity of bromelain as a result of isolation from degradation in the gastric environment by encapsulating it in a chitosan-guar gum hydrogel matrix that is crosslinked with glutaraldehyde to ensure the release of drugs targeted at the intestinal environment. Isolation of bromelain enzymes from pineapple stems is done through several steps, namely extraction, fractionation with ammonium sulfate, and dialysis. The specific activity of each fraction showed an increase, from crude enzymes (43.73 U/mg), fractionation with ammonium sulfate (369.01 U/mg), and dialysis (437.89 U/mg). Bromelain enzymes produced from dialysis are then encapsulated in the hydrogel matrix by post-loading to be tested for in vitro dissolution in artificial and intestinal environments. The hydrogel used was chitosan-guar gum with 3% (v/v) glutaraldehyde concentration, with swelling ratios of 75.83% and 68.39% respectively at pH 1.2 and 7.4. The concentration of bromelain isolated varies in each encapsulation process, each of which is 20 mg/L, 40 mg/L, and 60 mg/L so that the optimal encapsulation efficiency of 93.72% is obtained at 20 mg/L. Dissolution test results show the release of bromelain relatively high maximum in the artificial intestinal environment (73.53%) compared to the stomatch environment (19.11%) with maximum proteolytic activity respectively 0.43 U/mL and 0.18 U/mL in the artificial intestine and gastric environment. Dissolution results are then incorporated into the mathematical model of the zeroth, first order, Higuchi, and Korsmeyer-Peppas equations to determine the mechanism of drug dissolution by Fickian diffusion. Antiplatelet test showed a good percentage of inhibition of dialysis enzymes (46.60%) and dissolution solution (41.31%)."

"Since B A Tom 's found out the drag reduction phenomena, which occurs in polymer solutions in1948 many studies, have been done for it because we can apply to the economizing energy system thephenomena. The drag reduction is the application of the turbulent modification of the flow and we canapply it for the turbulent flow region. We measured the turbulent pressure loss in the square ducts andcircular pipe flow of a guar gum solution by manometer, and found that the friction factor in the ductsflow ware expressed by Re. Pressure loss in ducts ware measured for various concentrations of guargum and various diameters of pipes in water to study the effect of the additive on drag reduction, It isfound that guar gum acts like other drag reduction polymer additives because it constant the frictionfactor in laminar regime, modify the transition to turbulent flow, and reduces the friction factor the fullyturbulent regime."

"Luminar flow and turbulent of dilute polymer guar gum (fatter) solutions in smooth and in rough pineswas studied This experiment use in 25.4 mm of diameter pipe (PVC), which roughened by (k) 0, 34. 0,8and 1, 59 mm roughness value of sand grain and 250, 500 and 1000 ppm for additive concentration. Theresults show that flow properties ore influenced by polymer addition and surface roughness. In thetransition and turbulent flow regime without additive the increasing of friction coefficient appeared to beeffcted by wall condition alone. Addition of polymer to water is effective for rough pipe. For examplewith addition of 1000 ppm of polymer reduced drag in k/D = 0,03 rough pipe by 24 percent at Reynoldsnumber 2 x 10 , whereas in 250 ppm addition tested drag was reduced only 5 percent"