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"Pada penelitian ini dilakukan sintesis hidrogel poli(N-isopropilakrilamida)/poli((2- (dimetilamino)etil metakrilat) (PNIPAM/PDMAEMA) dalam bentuk interpenetrating polymer network (IPN) yang mempunyai sifat responsif terhadap temperatur dan pH dengan menggunakan inisiator amonium persulfat (APS), dan agen pengikat silang N,N’- metilenbisakrilamida (MBA). Sintesis dilakukan dengan pendekatan sequential-IPN dan dilakukan variasi konsentrasi PDMAEMA untuk melihat sifat swelling-deswelling dari hidrogel terhadap pengaruh perubahan temperatur dan pH. Hasil karakterisasi FTIR menunjukan hidrogel IPN berhasil disintesis yang ditandai dengan hilangnya puncak C=C vinil dan Csp2-H yang sebelumnya terdapat pada monomer. Penambahan konsentrasi PDMAEMA dalam hidrogel dapat meningkatkan nilai gel content dan menurunkan persen gelasi hidrogel IPN. Berdasarkan pengujian rasio swelling pada berbagai temperatur, hidrogel IPN-PNIPAM1/PDMAEMA0,5 memiliki nilai rasio swelling paling tinggi yakni 3,63 g/g dengan Tc 37°C. Sedangkan, pada uji rasio swelling hidrogel dengan berbagai pH didapatkan bahwa semakin banyak konsentrasi PDMAEMA dalam hidrogel, maka rasio swelling akan semakin besar pada pH 1,2, yaitu hidrogel IPNPNIPAM1/ PDMAEMA2 dengan rasio swelling sebesar 4,26 g/g. Didapatkan bahwa hidrogel IPN-PNIPAM1/PDMAEMA0,5 memiliki potensi untuk menjebak dan menghantarkan bahan aktif farmasi metformin-HCl dengan kemampuan penjebakan sebesar 3,68%, dan pelepasan sebesar 1,23% pada media dapar pH 1,2 dan 11,61% pada dapar pH 7,4 pada temperatur 37°C selama 2 jam.

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In this research, the synthesis of poly(N-isopropylacrylamide)/poly((2- (dimethylamino)ethyl methacrylate) hydrogel (PNIPAM/PDMAEMA) was carried out in the form of interpenetrating polymer network (IPN) which is responsive to temperature and pH using ammonium persulfate (APS) as an initiator, and N,N'- methylene bisacrylamide (MBA) as a crosslinker. The synthesis was carried out with a sequential- IPN approach by varying the concentrations of PDMAEMA to observe the swellingdeswelling properties of the hydrogel against changes in temperature and pH. The FTIR characterization showed that IPN hydrogel was successfully synthesized as indicated by the loss of the C=C vinyl and Csp2-H peaks that were previously present in the monomer. The addition of PDMAEMA concentration in the hydrogel can increase the gel content and decrease the IPN hydrogel’s gelation percentage. In the temperature-dependent swelling ratio test, the hydrogel IPN-PNIPAM1/PDMAEMA0.5 exhibits the maximum swelling ratio value of 3.63 g/g with Tc 37°C. Whereas the pH-dependent swelling ratio test discovered that the swelling ratio at pH 1.2 will increase when the hydrogel's PDMAEMA concentration rises, it is IPN-PNIPAM1/PDMAEMA2 hydrogel with the highest PDMAEMA concentration has the highest swelling ratio of 4.26 g/g. With an entrapment effectiveness of 3.68%, the IPN-PNIPAM1/PDMAEMA0.5 hydrogel can trap and distribute the active pharmaceutical drug metformin-HCl. The amount of metformin HCl released from the hydrogel in two hours at 37°C was 1.23% and 11.61% in buffers with HCl pH 1.2 and pH 7.4, respectively."

"Hidrogel poli([3-((2-(metakriloiloksi)etil)dimetilammonia) propana-1-sulfonat-ko-N-isopropilakrilamida) (P(SPE-ko-NIPAM)) memiliki responsivitas terhadap temperatur yang dimodifikasi dari dua tipe polimer berbeda yaitu bertipe LSCT dan UCST, dengan tujuan sebagai bahan penghantar aktif farmasi. Hidrogel P(SPE-ko-NIPAM) berhasil disintesis melalui metode polimerisasi radikal bebas menggunakan ammonium persulfat (APS) sebagai inisiator dan N-N’ metilenebisakrilamida (MBA) sebagai agen pengikat silang. Keberhasilan sintesis hidrogel P(SPE-ko-NIPAM) dibuktikan menggunakan fourier transform infrared (FTIR) yang ditandai dengan hilangnya puncak serapan C=C vinil. Nilai gel content menunjukkan bahwa hidrogel dengan komposisi 20 mol% SPE memiliki gel content paling kecil dan nilai gel content pada variasi waktu polimerisasi meningkat seiring dengan semakin lama waktu polimerisasi. Hasil uji responsivitas hidrogel P(SPE-ko-NIPAM) terhadap temperatur dipengaruhi oleh komposisi PSPE dan PNIPAM. Pengaruh waktu polimerisasi terhadap responsivitas temperatur yaitu semakin lama waktu polimerisasi akan menurunkan rasio kesetimbangan swelling (ESR), dan waktu polimerisasi tidak memberikan pengaruh terhadap nilai Tc. Hasil uji kinetika deswelling, bertambahnya komposisi SPE dan semakin lama waktu polimerisasi memiliki laju deswelling paling lambat. Berdasarkan uji swelling di berbagai temperatur menunjukkan bawah ESR terbesar dimiliki oleh hidrogel P(SPE20-ko-NIPAM80) dengan waktu polimerisasi 1 jam. Didapatkan hidrogel P(SPE20-ko-NIPAM80) memiliki kemampuan menjebak 2,75% dan mampu melepaskan 26,33% metformin-HCl dalam buffer pH 7,4 pada temperatur 37?C dalam rentang waktu selama 15 jam.

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Poly([3-((2-(methacryloyloxy)ethyl)dimethylammonio))propane-1-sulfonate-co-N isopropylacrylamide) (P(SPE-co-NIPAM)) hydrogels with temperature responsive properties modify of two different polymer types, namely the LSCT and UCST types, to be active pharmaceutical carrier materials. P(SPE-ko-NIPAM) hydrogel were synthesized by the mechanism of free-radical polymerization using ammonium persulfate (APS) as initiator and N-N' methylene bisacrylamide (MBA) as crosslinking agent. Hydrogel were characterized by using the Fourier Transform Infrared (FT-IR) and resulting in the nonappearance of C=C vinyl peak that indicates the polymerization process success. Gel content with a composition of 20 mol% SPE has the lowlest gel content and at various polymerization times increased with increasing polymerization time. The swelling test on several scales of temperature influenced by the composition of PSPE and PNIPAM. The effect of polymerization time on swelling test with several scales temperatureis ESR an increases with the polymerization time decrease, and polymerization time does not affect Tc value. Results of the rasio deswelling, an increase SPE composition and polymerization time have the slowest deswelling rate. The highest ESR results were obtained from hydrogel hydrogel P(SPE20-co-NIPAM80) with a polymerization time of 1 hour. Hydrogel P(SPE20-co-NIPAM80) was able to encapsulate 2.75% and the cumulative release 26.33% of metformin-HCl in buffer pH 7.4 at 37?C within 15 hours.

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"Material polimer untuk menyusun hidrogel harus dapat mengembang (swell) dan mempertahankan fraksi air pada strukturnya, namun tidak larut dalam air. Polimer alami memiliki gugus fungsi yang dapat menjadi pusat aktif reaksi dimana dapat dilakukan modifikasi untuk menghasilkan suatu polimer dengan karakteristik yang lebih baik. Kitosan merupakan polimer alami yang memiliki kekuatan struktur yang kurang dibandingkan kemampuan swelling. Sintesis hidrogel kitosan dengan metode full interpenetrating polymer network (IPN) dapat meningkatkan kekuatan struktur melalui ikat silang. Tahap pertama adalah sintesis jaringan polimer kitosan terikat silang asetaldehida. Tahap kedua adalah sintesis jaringan polimer PNVCL terikat silang N, N?-metilenbisakrilamida (MBA) melalui polimerisasi radikal bebas monomer NVCL dengan inisiator amonium persulfat (APS). Variasi waktu, rasio kitosan-PNVCL, konsentrasi agen pengikat silang, dan konsentrasi inisiator dipelajari untuk mengetahui kondisi optimum. Kondisi optimum diperoleh pada reaksi 2 jam dengan rasio kitosan/NVCL 90:10 (b/b %), konsentrasi MBA 0,5%, dan konsentrasi APS 3%. HSA kitosan-PNVCL memberikan rasio swelling 380,66% dan derajat ikat silang 60,85%. Karakterisasi HSA dilakukan dengan spektrofotometer Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), dan X-Ray Diffraction (XRD).

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Polymer material used for hydrogel should have the ability to swell and to keep water molecules in its structure without dissolving in water. Natural polymers has functional groups which can perform as active sites in modification to produce polymer with better characteristic. Chitosan is a natural polymer which has good swelling ability but lack of structural strength. Synthesis of chitosan hydrogel by interpenetrating polymer network (IPN) will increase its strength through crosslinking. In this research, the first step of modification was the synthesis of chitosan polymer network crosslinked by acetaldehyde. The next step was the synthesis of PNVCL polymer network crosslinked by N,N-methylbisacrylamide (MBA) through free radical polymerization of NVCL monomer with ammonium persulfat (APS) as the initiatior. Optimum reaction time, chitosan/PNVCL ratio (w/w %), concentration of crosslinker agent, and concentration of initiator had been observed. The optimum conditions were obtained as followed: 2 hours reaction, the ratio chitosan/PNVCL of 90:10 (w/w %), %-w MBA concentration of 0,5%, and APS concentration of 3%. The swelling ratio of the hydrogel was 380,66% while the crosslinking degree was 60,85%. Fourier transfor infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), and X-Ray diffraction (XRD) were used for the characterization of the hydrogel."

"Metode semi-Interpenetrating Polymer Network (Semi-IPN) merupakan salah satu metode untuk mensintesis hidrogel. Pada metode semi-IPN, kitosan mengalami ikat silang dengan agen pengikat silang asetaldehida/ formaldehida/ glutaraldehida membentuk jaringan polimer kitosan terikat silang yang kemudian berinteraksi dengan polimer metil selulosa yang berbentuk linier. Umumnya derajat ikat silang dan rasio swelling hidrogel semi-IPN akan dipengaruhi oleh waktu reaksi, rasio komposisi kitosan-metil selulosa, dan jenis agen pengikat silang yaitu asetaldehida, formaldehida, dan glutaraldehida. Kemampuan swelling dan derajat ikat silang hidrogel kitosan-metil selulosa semi-IPN yang optimum didapat pada rasio kitosan/metil selulosa 60:40 (b/b), agen pengikat silang formaldehida 2% (b/b), dan waktu reaksi 3 jam yaitu persen rasio swelling 785,6 % dan derajat ikat silang 50,8 %. Hidrogel kitosan-metil selulosa dengan metode semi-IPN memiliki rasio swelling dan derajat ikat silang lebih besar dibandingkan dengan hidrogel kitosan nonkovalen. Karakterisasi hidrogel kitosan-metil selulosa semi-IPN dilakukan dengan instrumen Fourier Transfrom Infra Red (FTIR), Differential Scanning Calorimetry (DSC), dan Scanning Electron Microscope (SEM).

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Semi-Interpenetrating Polymer Network (semi-IPN) method is one of many methods which used to synthesize hydrogels. In semi-IPN method, chitosan was crosslinked with crosslinking agent acetaldehyde/ formaldehyde/ glutaraldehyde to form crosslinked chitosan polymer network that will interracts with methyl cellulose polymer which have linear form. In general, degree of crosslinking and swelling ratio of semi-IPN hydrogels were influenced by reaction time, composition ratio of chitosan-methyl cellulose, and crosslinking agent acetaldehyde, formaldehyde, and glutaraldehyde. Swelling ability and degree of crosslinking of chitosan-methyl cellulose hydrogel with semi-IPN method optimally reach at chitosan/methyl cellulose ratio 60:40 (b/b) with formaldehyde crosslinking agent in 3 hours reaction time is 785,6 % swelling ratio and 50,8 % degree of crosslinking. Chitosan-methyl cellulose hydrogel with semi-IPN method has higher swelling ratio and degree of crosslinking compared to noncovalent chitosan hydrogel. Characterization of chitosan-methyl cellulose semi-IPN hydrogel using Fourier Transfrom Infra Red (FTIR), Differential Scanning Calorimetry (DSC), dan Scanning Electron Microscope (SEM) instrument."

"Metode IPN (Interpenetrating Polymer Network) baik semi maupun full IPNdapat digunakan untuk mensintesis hidrogel superabsorben (HSA) kitosan dan poli(N-vinil-kaprolaktam) (PNVCL) atau HSA kitosan-PNVCL. Pada metode full IPN jaringan polimer disintesis secara bertahap (sequential). Tahap pertama adalah sintesis jaringan polimer kitosan terikat silang asetaldehida dan homogenisasi dengan monomer N-vinil-kaprolaktam (NVCL) Tahap kedua adalah sintesis jaringan polimer PNVCL terikat silang N Nmetilenbisakrilamida (MBA) melalui polimerisasi radikal bebas monomer NVCL dengan inisiator amonium persulfat (APS) Hasil sintesis HSA kitosan-PNVCL full-IPN memiliki kekuatan struktur ikat silang dan kemampuan swelling yang baik Kekuatan struktur ikat silang meningkat dengan bertambahnya waktu reaksi, konsentrasi agen pengikat silang, inisiator, dan dipengaruhi rasio kitosan-PNVCL Kemampuan swelling HSA kitosan-PNVCL dengan kekuatan struktur ikat silang yang baik didapat pada rasio kitosan/PNVCL 70:30 (b/b %). HSA kitosan-PNVCL full-IPN memberikan persen derajat ikat silang yang tinggi (78,2%) dan kemampuan swelling yang baik (390,2%) Karakterisasi.

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The IPN (Interpenetrating Polymer Network) method, both semi and full IPN, can be used to synthesize chitosan and poly (N-vinyl-caprolactam) (PNVCL) superabsorbent hydrogels or HSA chitosan-PNVCL. In the full method of IPN polymer networks are synthesized sequentially. The first stage is the synthesis of crosslinked acetaldehyde chitosan polymer tissue and homogenization with N-vinyl-caprolactam (NVCL) monomer The second stage is synthesis of PNVCL polymer network bound by N Nmetilenbisakrilamida (MBA) through NVCL monomer free polymerization with ammonium persulfate (APS) initiator Synthesis of HSA chitosan-PNVCL full-IPN has crosslinked structure strength and good swelling ability The strength of crosslinking structure increases with increasing reaction time, concentration of crosslinking agent, initiator, and influenced by chitosan-PNVCL ratio Swelling ability of HSA chitosan-PNVCL with good cross-link structure strength is obtained at the chitosan / PNVCL ratio of 70:30 (b / b%). Full-IPN HSA chitosan-PNVCL gives a high percentage of crosslinking (78.2%) and good swelling ability (390.2%) Characterization Characterization."

"Hidrogel kitosan termodifikasi interpenetrating polymer network berhasil disintesis yaitu kitosan, kitosan terikat-silang, kitosan-poly N-vinyl-2-pyrrolidone semi-IPN dan kitosan-N-vinyl-2-pyrrolidone full-IPN. Hidrogel kitosan termodifikasi interpenetrating polymer network diloadingkan captopril. Metode loading obat ke dalam matriks hidrogel yaitu in situ and post loading. Konsentrasi obat yang terloading ke dalam matriks hidrogel divariasikan yaitu 12.5 mg; 25 mg; 37.5 mg and 50 mg. Loading obat dengan metode in situ loading dilakukan dengan menambahkan obat sebelum penambahan agen pengikat silang, sedangkan post loading dilakukan dengan mengimersikan hidrogel ke dalam larutan obat. hidrogel yang terloading obat disebut mikrokapsul. Efisiensi enkapsulasi ditentukan dengan mengimeriskan mikrokapsul ke dalam larutan buffer pH 7,4. Hidrogel dikarakterisasi dilakukan dengan penentuan derajat ikat-silang , rasio swelling , spketrofotometer FTIR dan mikroskop stereo. Derajat ikat-silang dari kitosan, kitosan terikat-silang, kitosan-poly N-vinyl-2-pyrrolidone semi-IPN dan kitosan-N-vinyl-2-pyrrolidone full-IPN adalah 51.62 , 54.65 , 70.15 dan 77.23 . rasio swelling dari kitosan, kitosan terikat-silang, kitosan-poly N-vinyl-2-pyrrolidone semi-IPN dan kitosan-N-vinyl-2-pyrrolidone full-IPN adalah 4412.88 , 2118.01 , 1748.65 dan 441,38 selama 1 jam. Konsentrasi optimum loading obat 12.5 mg and 25 mg. Hidrogel terloading obat disebut mikrokapsul. Pelepasan mikrokapsul captopril in situ and post loading selama 12 jam menunjukkan pelepasan lambat. Profil pelepasan obat pada pH 1,2 dari matriks hidrogel kitosan dan kitosan terikat-silang in situ loading secara difusi dan degradasi, sedangkan semi-IPN and full-IPN in situ loading secara difusi, pada pH 7,4 pelepasan obat mikrokapsul in situ loading secara difusi. Profil pelepasan obat dari mikrokaspul post loading pada pH 1,2 dan 7,4 terjadi secara difusi diikuti erosi matriks hidrogel.

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Preparation chitosan interpenetrating polymer network modified hydrogels have been successfuly. It were chitosan, chitosan crosslinked, semi IPN chitosan poly N vinyl 2 pyrrolidone and full IPN chitosan N vinyl 2 pyrrolidone. These hydrogels were loaded by captropil. Captopril was loaded within hydrogel matrix using both in situ and post loading method. Concentration variation of drug loaded were 12.5 mg 25 mg 37.5 mg and 50 mg. At in situ loading, drug was loaded during synthesis of hydrogel before the addition of crosslinking agent, while at post loading method hydrogels were immersed into a drug solution. This hydrogels loaded captopril called microcapsul. Encapsulation efficiency was evaluated in pH 7.4 solution. Hydrogels characterization including crosslinking degree , swelling ratio , FTIR spectrophotometer and stereo microscope. Crosslinking degree of chitosan, chitosan crosslinked, semi IPN and full IPN hydrogels were found to be 51.62 , 54.65 , 70.15 and 77.23 respectively. Swelling ratio of chitosan, chitosan crosslinked, semi IPN and full IPN hydrogels were 4412.88 , 2118.01 , 1748.65 and 441,38 for 1 hour, respectively. The optimum drug concenration was 12.5 mg and 25 mg. Hydrogels loading drug called microcapsule. Release of captopril microcapsules by in situ and post loading shown that slow release for 12 hour. Profile of release drug from chitosan and chitosan crosslinked hydrogels by in situ loading at pH 1,2 through difussion and degradation, while semi IPN and full IPN hydrogels by in situ loading at pH 1,2 through difussion. At pH 7,4 of profile of release drug from microcapsules through difussion. Profile of release drug at pH 1,2 and 7,4 from microcapsules by post loading through difussion followed erotion."

"ABSTRAKStarch telah banyak dimanfaatkan sebagai bahan encapsulasi untuk sistem penghantar obat. Namun begitu, hidrogel starch mudah terdegradasi selama proses metabolisme dalam perut. Modifikasi terhadap pati diperlukan untuk meningkatkan proses enkapsulasi obat dalam sistem penghantar obat, terutama untuk obat gastrointestinal. Dalam penelitian ini, disintesis tiga modifikasi hidrogel berbahan dasar starch yaitu hydrogel starch terikat silang, semi dan full interpenetrating polymer network IPN hydrogel menggunakan PVP. Hydrogel starch juga disintesis sebagai bahan pembanding. Karakterisasi biomaterial dalam paper ini adalah uji swelling, observasi dengan menggunakan mikroskop stereo, DSC, FTIR. Kemudian, digunakan amoxicillin untuk uji obat. Hasil penelitian ini menunjukkan bahwa full-IPN memiliki karakteristik yang paling padat dan elastis,yang diikuti dengan semi-IPN, starch terikat silang dan starch hidrogel yang tidak termidifikasi diurutan terakhir. Namun, semi-IPN menunjukkan hasil yang lebih baik dalam implementasinya untuk aplikasi enkapsulasi obat. Hal ini ditunjukan dengan nilai efisiensi enkapsulasi obat dalam matrik hidrogel lebih tinggi dibandingkan dengan hidrogel pati termodifikasi lainnya dan hasil pengujian pelepasan obat dari matrik hidrogel semi-IPN lebih terkontrol

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ABSTRACTStarch has been widely used as an encapsulation material for drug delivery system. However, starch hydrogel is very easily degraded during metabolism in human stomach. Modification of this material is needed to improve the encapsulation process in drug delivery system, especially for gastrointestinal drug. In this research, three modified starch based hydrogels are synthesized i.e. crosslinked starch hydrogel, semi and full interpenetrating polymer network IPN starch hydrogel using Poly N Vinyl Pyrrolidone . Non modified starch hydrogel was also synthesized as a control. All of those samples were compared as biomaterials, floating drug delivery, and their ability in loading drug test. Biomaterial characterizations were swelling test, stereomicroscopy observation, Differential Scanning Calorimetry DSC , and Fourier Transform Infrared Spectroscopy FTIR . Lastly, amoxicillin was used as test drug. Results of this research was shown that full IPN has the most dense and elastic texture, followed by semi IPN, Crosslinked, and Non modified in the last position. However, the semi IPN showed better results in the implementation of drug encapsulation applications. This was proofed by the efficiency of drug encapsulation within a hydrogel matrix was the highest in compared to other modified starch hydrogel and in drug release testing results of the semi IPN hydrogel matrix was controlled"

"Polimer responsif temperatur hidrogel poli(N,N-dimetilakrilamida-ko-N-isopropilakrilamida) (P(DMA-ko-NIPAM)) disintesis melalui polimerisasi radikal bebas dengan inisiator amonium persulfat (APS) dan agen pengikat silang N,N-metilen-bis-akrilamida (MBA). Hidrogel P(DMA-ko-NIPAM) dikarakterisasi, kandungan gelnya, serta keberhasilan polimerisasinya. Keberhasilan sintesis hidrogel P(DMA-ko-NIPAM) dibuktikan dengan tidak munculnya peak gugus vinil dari monomer pada spektra FTIR hidrogel P(DMA-ko-NIPAM). Hasil uji rasio swelling menunjukkan sifat responsif temperatur hidrogel P(DMA-ko-NIPAM), dengan tren menurunnya rasio swelling dengan peningkatan temperatur. Rasio swelling terbesar pada berbagai temperatur dimiliki oleh hidrogel dengan komposisi DMA dan NIPAM yaitu 35 dan 65 mol% dan pada konsentrasi MBA 3%. Pengaruh pH, konsentrasi awal larutan logam berat, dan temperatur terhadap kapasitas adsorpsi ion logam berat oleh hidrogel P(DMA-ko-NIPAM) diteliti. Ion logam berat Co(II) dan Pb(II) menunjukkan pH optimum kapasitas adsorpsi di pH 5,5, sedangkan Cu(II) di pH 4,5. Kehadiran ion logam berat dapat menurunkan titik temperatur transisi fasa (Tc) hidrogel P(DMA-ko-NIPAM) dari 40oC menjadi 35oC. Kapasitas adsorpsi ion logam berat meningkat dengan semakin besarnya konsentrasi awal larutan logam berat, dan dengan semakin rendahnya temperatur. Serta model Langmuir adalah model isoterm adsorpsi paling cocok untuk ketiga ion logam berat. Kapasitas adsorpsi hidrogel P(DMA-ko-NIPAM) untuk ion logam berat menurun dengan urutan sebagai berikut: Co(II) > Cu(II) > Pb(II).

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The temperature-responsive polymer hydrogels poly(N,N-dimethylacrylamide-co-N-isopropylacrylamide) (P(DMA-co-NIPAM)) was synthesized via free radical polymerization with ammonium persulphate (APS) initiator and N,N-methylene-bis-acrylamide (MBA) crosslinking agent. The P(DMA-co-NIPAM) hydrogels were characterized for their gel content, and the success of their polymerization. The successful synthesis of P(DMA-ko-NIPAM) hydrogels was evidenced by the absence of vinyl group peaks from the monomer in the FTIR spectra of P(DMA-ko-NIPAM) hydrogels. The results of the swelling ratio test showed the temperature responsiveness of the P(DMA-co-NIPAM) hydrogels, with a trend of decreasing swelling ratio with increasing temperature. The largest swelling ratios at various temperatures belonged to hydrogel with DMA and NIPAM compositions of 35 and 65 mol% and at 3% MBA concentration. The effect of pH, initial concentration of heavy metal solution, and temperature on the adsorption capacity of heavy metal ions by P(DMA-co-NIPAM) hydrogel was investigated. Heavy metal ions Co(II) and Pb(II) showed optimum pH of adsorption capacity at pH 5.5, while Cu(II) at pH 4.5. The presence of heavy metal ions can lower the phase transition temperature (Tc) of P(DMA-co-NIPAM) hydrogel from 40oC to 35oC. The adsorption capacity of heavy metal ions increases with the increasing initial concentration of heavy metal solution, and with the lowering of temperature. In addition, Langmuir model was the most suitable adsorption isotherm model for the three heavy metal ions. The adsorption capacity of P(DMA-co-NIPAM) hydrogel for heavy metal ions decreased in the following order: Co(II) > Cu(II) > Pb(II)."

"ABSTRAKCaptopril merupakan antihipertensif golongan angiotensin converting enzyme inhibitor ACEI yang banyak digunakan untuk mengontrol tekanan darah sekaligus mengurangi penyakit jantung. Suatu penelitian melaporkan bahwa captopril bekerja dengan menginhibisi konversi enzim ACE I menjadi ACE II, mengurangi plasma angiotensin II dan level aldosteron, meningkatkan plasma renin, dan menghasilkan penurunan tekanan darah yang signifikan bagi penderita hipertensi. Dibalik manfaatnya yang baik bagi kesehatan, captopril diketahui memiliki waktu paruh biologis yang singkat dalam tubuh dan memerlukan frekuensi administrasi yang berulang. Suatu sistem penghantaran obat yang tepat diperlukan untuk memodifikasi pelepasan captopril dalam tubuh. Salah satunya menggunakan hidrogel berbasis kitosan yang terikat silang poli N-vinil-2-pirolidon atau PVP melalui interpenetrating polymer network IPN . Meskipun efisiensi kapsulasi dan pelepasannya secara umum telah diteliti, informasi tentang kinetika swelling matriks hidrogel dan mekanisme pelepasannya belum diketahui. Penelitian ini akan berfokus pada kedua hal tersebut. Sebagai perbandingan, hidrogel yang akan diteliti meliputi hidrogel kitosan nonkovalen, hidrogel kitosan terikat silang, hidrogel kitosan-PVP semi-IPN, dan hidrogel kitosan-NVP full-IPN. Kinetika swelling akan ditentukan melalui analisis gravimetri mengikuti hukum laju pseudo-orde pertama dan hukum laju pseudo-orde kedua. Mekanisme pelepasan akan ditentukan melalui persamaan laju orde nol, orde satu, model Higuci, dan model Korsemeyer-Peppas.

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ABSTRACTCaptopril is an antihypertensive class of angiotensin converting enzyme inhibitors ACEI that is widely used to control blood pressure disease. A study reported that captopril works by inhibiting the conversion of the ACE I enzyme to ACE II, reducing plasma angiotensin II and aldosterone levels, increasing plasma renin, and generating a significant drop in blood pressure for hypertensive patients. Behind its good health benefits, captopril is known to have short biological half lives in the body and requires repeated administration frequencies. An appropriate drug delivery system is needed to overcome the release of captopril in the body. One way to achieved it is by using a crosslinked poly N vinyl 2 pyrrolidone chitosan based hydrogel or PVP via an interpenetrating polymer network IPN . However, information about the kinetics of the swelling of the hydrogel matrix and its release mechanism is unknown. This research will focus in its cases. In comparison, the hydrogels to be studied are noncovalent hydrogel, cross linked hydrogel, semi IPN chitosan PVP hydrogel, and full IPN chitosan NVP hydrogel. Kinetics of swelling will be determined by the gravimetric analysis of pseudo first order and the pseudo second order rate law. The mechanism will be determined by the zero order rate equation, first order, Higuci model, and Korsemeyer Peppas model."