Tujuan kajian ini adalah untuk menilai sifat-sifat fizikokimia Radix Glycyrrhizae sebagai bahan eksipien untuk pembuatan tablet dengan kaedah pemampatan terus dan membandingkannya dengan eksipien komersil iaitu laktosa, selulosa mikrohablur (MCC) dan kalsium laktat pentahidrat (Puracal). Saiz partikel untuk semua sampel yang digunakan dalam kajian ini dihadkan pada 200-250µm. Hasil imbasan elektron mikroskop menunjukkan partikel Radix Glycyrrhizae mempunyai kepelbagaian saiz dan bentuk yang tidak seragam seperti laktosa berbanding MCC yang lebih bersifat jejarum dan Puracal yang bersifat sfera dan poros. Keupayaan sampel untuk dimampatkan, ketumpatan partikel sampel, kesan kelembapan ke atas tegasan pengenduran dan keliangan tablet diuji serta dibandingkan dengan eksipien komersil yang lain. Sifat ikatan dari sampel Radix Glycyrrhizae ini pula dikaji dengan menghitung kekuatan tegangan melalui kaedah pemampatan diametral dan turut dilakukan perbandingan. Radix Rlycyrrhizae memiliki ketumpatan sebenar serbuk iaitu 1.5746 g/cc manakala laktosa, selulosa mikrohablur dan kalsium laktat pentahidrat masing-masing 1.5476, 1.6654 dan 1.3506 g/cc. Radix Rlycyrrhizae juga di dapati mempunyai daya ketermampatan yang sederhana sebagaimana laktosa berbanding Puracal dan MCC yang jauh lebih baik sifatnya. Kajian kesan kelembapan menunjukkan kekuatan tablet Radix Glycyrrhizae, Puracal, laktosa dan MCC dipengaruhi perubahan suhu. Hasil kajian analisis Heckel pula menunjukkan bahawa Radix Glycyrrhizae bersifat aliran plastik sebagaimana MCC manakala laktosa dan Puracal lebih bersifat rapuh. Keputusan ujian ke atas sifat pemampatan dan pemadatan mendapati bahawa Radix Kesimpulannya, Radix Glycyrrhizae boleh digunakan sebagai eksipien dalam pembuatan tablet melalui kaedah pemampatan terus dan ciriciri fisikokimianya sebagai eksipien adalah setanding dengan eksipien komersial.
Polyvinyl chloride (PVC) and ammonio methacrylate copolymer (Eudragit RS 100) were used as models in binary mixture tablets of direct compression study. Eudragit RS 100 is a copolymer synthesized from acrylic and methacrylic acid esters with a low content of quaternary ammonium groups. Combination of PVC and Eudragit RS 100 of different polarities and knowing the surface free energy values allow the possibility of predicting the tensile strength of the tablets. Specimens of 500 mg in the form of thin plates (25 mm x 12.5 mm), were made by compressing each powder at 20 000 MP a compression pressure using a special punch and die set. A Howden Universal Testing Machine was used to compress the powder. Contact angle measurements of the samples were carried out using a Wilhelmy balance, ran by a Cahn Dynamic Contact Angle Machine while different test liquids media such as water, glycerol, formamide and PEG 200 were used in the study. The surface free energy values of the solid materials were calculated using Wu's equation. The results showed large differences between the advancing and receding contact angle values for both materials when tested with glycerol: PVC (0) and PVC (0,) were 93.2 and 65.24 while Eudragit RS 100 (0) and Eudragit RS 100 (0) were 94.56 and 68.18 respectively. The surface free energy values for PVC using PEG 200-glycerol liquid pair were Is: 38.01, ysci: 33.42, ysP: 4.59 and for Eudragit RS 100 using formamide-glycerol liquid pair were ys: 75.03, yd: 51.66, ysP : 23.37, respectively. The results showed harder solid material like Eudragit RS 100 had higher surface free energy compared to elastic material like PVC.
Penggunaan formulasi tablet pelepasan tertahan untuk dadah anti-inflamatori bukan steroid (DAIBS) seperti aspirin berupaya melindungi lapisan perut dari kesan buruk jus asid tubuh. Kajian ini dilakukan untuk menilai keberkesanan formulasi tablet matriks pelepasan tertahan dengan kepelbagaian kepekatan polimer bersama ketoprofen sebagai model. Tablet dibangunkan dengan menggunakan kaedah granulasi basah yang terdiri daripada polimer hidrofilik (hidroksipropil metilselulosa), polimer hidrifobik bersandar pada pH (Eudragit L100-55) dan polimer tak bersandar pada pH (Eudragit R100) sebagai bahan asas pembentukan matriks pada kepekatan 10, 20 dan 30%b/b. Semua formulasi dimampatkan dengan menggunakan mesin pentabletan yang mempunyai penebuk berbentuk cembung bersaiz 10 mm. Tablet yang terhasil diuji daripada segi keseragaman berat, kekerasan, kerapuhan, ketebalan, peratus kandungan dadah dan kajian pelepasan in vitro menggunakan kaedah BP 2007. Hasil menunjukkan kadar pelepasan dadah dikawal oleh jenis dan kepekatan polimer di dalam formulasi matriks. Secara umumnya peningkatan kepekatan kandungan polimer di dalam tablet matriks didapati mengurangkan kadar pelepasan dadah. Perbandingan polimer melalui kepekatan yang sama menggunakan t50%, pula mendapati terdapat perbezaan statistik bermakna (p<0.05) pada kadar pelepasan dadah. Berdasarkan kepada pelepasan dadah dalam kajian in vitro, polimer hidrofobik bersandar pada pH (Eudragit L100-55) menunjukkan profil pelepasan dadah secara tertib sifar yang terbaik berbanding polimer yang lain.
Nata de coco, a dessert originally from the Philippines is produced by fermentation of coconut water with a culture of Acetobacter xylinum, a gram negative bacterium. Acetobacter xylinum metabolizes glucose in coconut juice and converts it into bacterial cellulose that has unique properties including high purity, crystallinity and mechanical strength. Because the main component of nata de coco is bacterial cellulose, nata de coco was purified, extracted and characterized to determine whether pure cellulose could be isolated from it. The FTIR spectra of bacterial cellulose from nata de coco showed distinguish peaks of 3440 cm-1, 2926 cm-1, 1300 cm-1, 1440 cm-1, 1163 cm-1 and 1040 cm-1, which correspond to O-H stretching, C-H stretching, C-H bending, CH2 bending, C-O-C stretching and C-O stretching, respectively, and represent the fingerprints of pure cellulose component. Moreover, the FTIR curve showed a pattern similar to other bacterial cellulose spectra reported by report. Thermal analysis showed a DTG peak at 342°C, which falls in the range of cellulose degradation peaks (330°C - 370°C). On the other hand, the TGA curve showed 1 step of degradation, and this finding confirmed the purity of nata de coco. Bacterial cellulose powder produced from nata de coco was found to be soluble only in cupriethylenediamine, a well known solvent for cellulose; thus, it was confirmed that nata de coco is a good source of bacterial cellulose. The purity of bacterial cellulose produced from nata de coco renders it suitable for research that uses pure cellulose.
In this research, a novel method was performed to obtain hydrogel with superior thermal stability by incorporation
of cellulose nanocrystals (CNC) into gelatin based hydrogel. Glutaraldehyde was used as cross-linker due to its high
chemical reactivity towards NH2
group on gelatin. Different ratio of gelatin/CNC hydrogel was produced in order to study
the effects of CNC towards the swelling behaviour and thermal stability of gelatin based hydrogel. The obtained hydrogel
was subjected to Fourier transform infrared (FTIR) to verify that gelatin had been cross-linked, swelling test with different
pH for swelling behaviour and thermogravimetric analysis (TGA) for thermal stability. The presence of C=N stretching
group in the FTIR spectrum for gelatin/CNC hydrogel indicated that the cross-linking reaction between gelatin monomer
had been successfully carried out. The hydrogel showed impressive pH sensitivity and maximum swelling was obtained
at pH3. The TGA results clearly showed that the incorporation of CNC into gelatin was able to produce hydrogel with
higher thermal stability compare to neat gelatin.
Kajian ini telah menilai kesan pelbagai faktor persekitaran terhadap darjah pengembungan hidrogel selulosa bakteria-asid akrilik. Campuran akues selulosa bakteria-asid akrilik (4:1) telah disediakan dan didedahkan dengan irradiasi alur elektron pada 35 kGy dan 50 kGy. Kadar pengembungan di bawah pengaruh pH, suhu dan kekuatan ionik telah dikaji dari 1 hingga 24 jam. Darjah pengembungan hidrogel bergantung kepada dos irradiasi yang diberi: hidrogel yang telah disintesis pada 50 kGy mempunyai darjah pengembungan yang lebih tinggi secara signifikan (p<0.0001) dalam metanol (619%) berbanding air suling (510%) pada suhu bilik selepas 24 jam. Kekuatan ionik persekitaran mempengaruhi dengan peningkatan kepekatan natrium klorida menurunkan darjah pengembungan. Hidrogel juga peka terhadap perubahan pH: pengembungan meningkat dengan peningkatan pH dan nilai optimal dicapai pada pH 7. Selain itu pengembungan juga meningkat dengan peningkatan suhu dari 25°C sehingga 50°C. Kesimpulannya, keupayaan hidrogel selulosa bakteria-asid akrilik dedahan irradiasi elektron bertindak balas terhadap pelbagai rangsangan faktor persekitaran, menjadikan ia satu bahan yang boleh dibangunkan sebagai sistem penyampaian aktif untuk dadah, protein dan hormon.
There has been an increasing interest in the use of natural materials as drug delivery vehicles due to their biodegradability, biocompatibility and ready availability. These properties make bacterial cellulose (BC), from nata de coco, a promising biopolymer for drug delivery applications. The aim of this study was to investigate the film-coating and drug release properties of this biopolymer. Physicochemical, morphological and thermal properties of BC films were studied. Model tablets were film coated with BC, using a spray coating technique, and in vitro drug release studies of these tablets were investigated. It was found that BC exhibited excellent ability to form soft, flexible and foldable films without the addition
of any plasticizer. They were comparable to Aquacoat ECD (with plasticizer) in tensile strength, percentage elongation and elasticity modulus. Differential scanning calorimetry (DSC) BC showed a high Tg value indicating thermally stability of films. These results suggest that BC can be used as novel aqueous film-coating agent with lower cost and better film forming properties than existing film-coating agents.