Studies on the Properties of Chitosan-Starch Beads and their Application as Drug Release Materials

In this work, chitosan and blends of chitosan-starch beads were prepared and crosslinked with glutaraldehyde (pentane-1,5-dial). The blends were prepared with 1:1, 2:1 and 3:1 chitosan-starch ratios. Metformin hydrochloride (N,N-dimethylimidodicarbonimidic diamide hydrochloride), a type 2 diabetis drug, was incorporated into them. The materials were subjected to swellability tests and the effects of time and pH were established. Fourier Transformed Infrared Spectrophotometeric (FTIR) analysis was also carried out on the materials and their potentials as drug release systems studied. The results obtained from the FTIR studies showed that the uncrosslinked chitosan-starch bead showed O-H stretching band at 3424cm-1 and N-H band at 1640cm-1. The chitosan-starch bead also showed a band at 597cm-1 corresponding to C-Cl band, due to the presence of metformin hydrochloride in the bead and its O-H stretching band was very strong and broad due to the numerous –OH groups in starch and chitosan. The results of swelling studies showed that the percent swellability of the polymer matrices increased in both the crosslinked and uncrosslinked beads as the amount of starch in them increased. The uncrosslinked chitosan beads had maximum swelling of 83.74%, while its crosslinked analogue had 47.93% in acidic medium (pH 2.06) within the range of test period of 60 minutes. The amount of drug released by the 1:1, 2:1 and 3:1 crosslinked chitosan-starch beads (13.90, 13.60, and 12.30mg/L, respectively) was much lower than that of their uncrosslinked analogues (22.50, 20.90, and 16.60mg/L, respectively) after 120 minutes, suggesting that the release of drug is delayed by crosslinking. This suggests that the crosslinked chitosan-starch beads can be used for regulating release of drugs in solid dosages such as beads or tablets.Keywords: chitosan, chitosan-starch beads, drug release, metformin hydrochloride, swellin

Effect of Crosslinking Agent Ratio and Temperature on Degree of Swelling in Polymer Hydrogels

In the present work graft polymers PVA-U were prepared from reaction polyvinyl alcohol PVA  and urea. Were blending 8% PVA-U and 5% Hydroxypropyl methylcellulose HPMC  in different ratio 100:0, 75:25 and 50:50  with using glutaraldehyde as crosslinked agent in different ratio 0.5, 0.75, 1.0 and 1.25 ml/dl. The structure of PVA-U and blend PVA-U/HPMC hydrogel was characterized by Fourier transform infrared spectroscopy FTIR, differential scanning colorimeter DSC and scanning electron microscopy SEM. Studies are made on swelling behavior for all prepared samples in different media of PH (neutral, acidic and alkaline) and deionised water.. It was observed that swelling ratio of hydrogel decreased by increasing the concentration of glutaraldehyde. The swelling ratio was measured for some hydrogel in pH7 at three different temperatures (25, 37, 50) as function of time, it was observed that swelling ratio increased with increased temperatures.. Keywords: Blend polymers, Hydrogel polymers, PVA, HPMC, Glutaraldehyd

Pengaruh Penambahan Plasticier Gliserol terhadap Karakteristik Hidrogel Kitosan-glutaraldehid untuk Aplikasi Penutup Luka

PENGARUH PENAMBAHAN PLASTICIER GLISEROL TERHADAP KARAKTERISTIK HIDROGEL KITOSAN-GLUTARALDEHID UNTUK APLIKASI PENUTUP LUKA ABSTRAK Telah dilakukan penelitian untuk mengetahui pengaruh penambahan plasticizer gliserol terhadap karakteristik hidrogel kitosan-glutaraldehid untuk aplikasi penutup luka. Penambahan gliserol bertujuan agar hidrogel kitosan-glutaraldehid lebih fleksibel dan memiliki sifat mekanik yang baik sehingga dapat diaplikasikan sebagai penutup luka sesuai dengan standar yang ada. Pembuatan hidrogel dilakukan dengan cara mencampurkan kitosan yang dilarutkan dalam 1% asam asetat dengan 1% larutan glutaraldehid pada perbandingan 50 : 3 (v/v) dan ditambahkan gliserol dengan variasi volume 1 ml – 4 ml. Konsentrasi gliserol yang digunakan tidak lebih dari 2%. Berdasarkan penelitian yang telah dilakukan, penambahan gliserol menyebabkan ketebalan, kuat tarik, dan kemampuan mengabsorbsi cairan hidrogel menurun; elongasi dan ketahanan terhadap air hidrogel meningkat; serta struktur hidrogel menjadi lebih halus. Berdasarkan hasil uji sifat mekanik, hasil terbaik ditunjukkan oleh hidrogel kitosan-glutaraldehid-gliserol dengan penambahan gliserol 2% sebanyak 2 ml, yang memiliki nilai kuat tarik sebesar 14,34 ± 1,90 MPa dan elongasi sebesar 2,40 ± 0,91% yang memenuhi standar sifat mekanik kulit manusia. Struktur permukaan hidrogel tersebut halus, homogen, memiliki ketahanan terhadap air sebesar 24,78 ± 6,57% serta mampu mengabsorbsi cairan lebih dari 99,9% yaitu sebesar 149,65 ± 22,46% yang merupakan karakteristik penting hidrogel. Jadi, dapat disimpulkan bahwa hidrogel kitosan-glutaraldehid-gliserol dengan penambahan gliserol 2% sebanyak 2 ml dapat diaplikasikan sebagai penutup luka. Kata kunci: Glutaraldehid, Gliserol, Hidrogel, Kitosan, Penutup Luka, Plasticizer THE EFFECT OF ADDITION GLYCEROL AS PLASTICIER TO THE CHARACTERISTICS OF CHITOSAN-GLUTARALDEHYDE HIDROGEL FOR WOUND DRESSING APPLICATION ABSTRACT The research had been done to determine the effect of addition glycerol as plasticizer to the characteristics of chitosan-glutaraldehyde hydrogel for wound dressing application. The addition of glycerol was served to increase flexibility and improve the mechanical properties of chitosan-glutaraldehyde hydrogel that can be applied as a wound dressing accordance with existing standards. Preparation of hydrogel was made by mixing chitosan dissolved in 1% acetic acid with 1% glutaraldehyde solution with ratio 50 : 3 (v/v) and added by glycerol with variation of 1 ml - 4 ml. The glycerol concentration used no more than 2%. Based on the research that had been done, the addition of glycerol caused thickness, tensile strength, and the absorption ability of hydrogel was decreased; elongation and water resistance of hydrogel increased; and the surface structure of hydrogel is more smooth. Based on the result of mechanical properties, the best characteristics of chitosan-glutaraldehyde-glycerol hydrogel is shown with the addition of 2 ml glycerol 2% composition which has a value of tensile strength of 14,34 ± 1,90 MPa and elongation at 2,40 ± 0,91 % that meet the standards of the mechanical properties of human skin. The structure of that hydrogel surface is smooth, homogeneous, has a water resistance of 24,78 ± 6,57%, and is able to absorb liquid more than 99,9% in the amount of 149,65 ± 22,46 % which is an important characteristic of the hydrogel. So, the chitosan-glutaraldehyde-glycerol hydrogel with the addition of 2 ml glycerol 2% can be applied as a wound dressing

Evaluation of the Effect of Acetylation and Oxidation on Some Functional Properties of Starch Isolated from Dioscorea dumetorum (Wild)

The starch extracted from the wild species of Dioscorea dumetorum were characterized for ash and moisture content, crude fibre, protein and fat. The modified starches were prepared by pre-treatment of the native starch with alkaline and acidic solution at room temperature prior to modification using hypochlorite for oxidation and acetic anhydride for acetylation. Effects of acetylation and oxidation on some functional properties of the starch were evaluated. Variations were observed in the functional properties of the starch as swelling power ranged from 10.3-10.9, solubility index 6.2-7.6% and apparent amylase content 16.05-21.02%. Oxidized starch showed higher paste clarity than the acetylated and native starches at pH 12. The paste clarity of both native and modified starches were found to be pH dependent. The swelling-power of the native and modified starches put them in the category of highly restricted-swelling starch.Keywords: Dioscorea dumetorum, Starch, Acetylation, Oxidatio

Effect of Graft Ratio PVA-Urea and Different Concentration Blend Polymers on Swelling Ratio

The polymeric materials still important parameters for drug delivery research.In the present work two graft polymers PVA-U were prepared from reaction  polyvinyl alcohol PVA  and urea by using two ratio concentration from urea. Were blending 8% PVA-U and 5% Hydroxypropyl methylcellulose HPMC  in different ratio 100:0, 75:25 and 50:50  with using glutaraldehyde as crosslinked agent 0.75 ml/dl. The structure of PVA-U and blend PVA-U/HPMC hydrogel was characterized by Fourier transform infrared spectroscopy FTIR, differential scanning colorimeter DSC and scanning electron microscopy SEM. Studies are made on swelling behavior for all prepared samples in different media of PH (neutral, acidic and alkaline) and deionised water.. It is found that swelling ratio depends on media and proportion of substitutes in graft polymers, in high graft polyvinyl alcohol the swelling ratio increased with pH increased from pH2 < dionized water ≤ PH7 < PH10, But in low graft polyvinyl alcohol the swelling ratio increased with pH increased from pH2 < PH10 < dionized water ≤ PH7. Swelling ratio of polymeric hydrogels was affected by composition blend polymers and it was increased by increasing the concentration of HPMC and decrease time for complete swelling. Keywords: Blend polymers, Hydrogel polymers, PVA, HPMC, Glutaraldehyd

pH ‐ responsive studies of bacterial cellulose / chitosan hydrogels crosslinked with Genipin: swelling and drug release behaviour

Semi interpenetrating hydrogels (semi‐IPN) of bacterial cellulose (BC) and chitosan (Ch) crosslinked with genipin were prepared and characterised using Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Infrared spectra showed amide I and II absorption peaks at 1632 and 1554 cm−1 and C−N stretching absorptions at 1250 and 1020 cm−1, respectively, for crosslinked hydrogels. The fibrous structure of BC and the porosity in the hydrogels were revealed by SEM. Swelling of hydrogels was sensitive to pH, and maximum at pH 1.0. Swelling of non‐crosslinked samples decreased as the pH increased. However, with crosslinked hydrogels, swelling increased as chitosan ratio increased at low pH, as well as with increase in BC ratio at high pH. Free, bound and intermediate water types in hydrogels were revealed by DSC. The release kinetics of Quetiapine fumarate (QF), an antipsychotic drug used for the treatment of Schizophrenia was studied using UV spectrometry, followed predominantly, the Higuchi model at all pH for crosslinked hydrogels. The transport mechanism of hydrogels was a combination of non‐Fickian and Super Case II. Crosslinked hydrogels showed controlled drug release behaviour. These hydrogel systems possess potential application in pharmaceutical field as all chemicals used in the development of the hydrogels are non‐toxic, with BC−Ch 60:40 showing most promising potential

MANGO STARCH: ITS USE AND FUTURE PROSPECTS

Mango (Mangifera indica L.) is tropical fruit with high nutritional value. The aim of present work was to isolate the starch from black variety of mango and evaluate the physicochemical as well as functional properties. Starch is widely used in the food and pharmaceutical industries for various applications. These industries depend on crops that are also the traditional sources of food resulting high demands with consequence economic implications. The results showed that the moisture content (14.93%) was higher while ash content (0.12%) was low. Amylose content was 35.06%. It was observed that the onset gelatinization temperature of the starch ranged from 50°C whereas, the conclusion gelatinization temperature was from 91-92.5°C. The starch show adequate properties and could be alternative source for the production of industrial products that may require starch.Â

The preparation of HEMA-MPC films for ocular drug delivery

There is a need to prolong drug residence time using a biocompatible formulation in the subconjunctival space after surgery to treat glaucoma. Drug releasing discs were prepared with 2-(hydroxyethyl)methacrylate (HEMA) and 2-methacryloyl-oxyethyl phosphorylcholine (MPC). The ratio of bound water (Wb) to free water (Wf) ratio increased from 1:0.3 to 1:6.8 with increasing MPC (0 to 50%, w/w). The optimal balance between water content, SR and mechanical strength were obtained with 10% MPC (w/w) hydrogels. Water-alcohol mixtures were examined to facilitate loading of poorly soluble drugs, and they showed greater hydrogel swelling than either water or alcohol alone. The SR was 1.2 ± 0.02 and 3.3 ± 0.1 for water and water:ethanol (1:1) respectively. HEMA-MPC (10%) discs were loaded with dexamethasone using either water:ethanol (1:1) or methanol alone. Drug release was examined in an outflow rig model that mimics the subconjunctival space in the eye. Dexamethasone loading increased from 0.3 to 1.9 mg/disc when the solvent was changed from water:ethanol (1:1) to methanol with the dexamethasone half-life (t½) increasing from 1.9 to 9.7 days respectively. These encouraging results indicate that HEMA-MPC hydrogels have the potential to sustain the residence time of a drug in the subconjunctival space of the eye