Current Issue : April - June Volume : 2015 Issue Number : 2 Articles : 7 Articles
Bilayer tablets of aceclofenac sodium were developed using carboxymethylated white\nyam (Dioscorea rotundata) starch (CWY) for a fast release layer (2.5, 5.0, and 7.5%\nw/w), and acid-hydrolyzed bitter yam (Dioscorea dumetorum) starch (ABY) for a sustaining\nlayer (27% w/w). Sodium starch glycolate (SSG) and hydroxypropyl methyl cellulose\n(HPMC) were used as standards. The starches were characterized using Fourier Transform\nInfrared spectroscopy (FT-IR), particle size, swelling power, densities and flow analyses.\nMechanical properties of the tablets were evaluated using crushing strength and friability\nwhile release properties were evaluated using disintegration and dissolution times.\nDistinctive fingerprint differences between the native and modified starches were revealed\nby FT-IR. Carboxymethylation produced starches of significantly (p < 0.05) higher swelling\nand flow properties while acid-modification produced starches of higher compressibility.\nBilayer tablets containing ABY had significantly higher crushing strength and lower\nfriability values (p < 0.05) than those containing HPMC. Crushing strength increased while\nfriability values decreased with increase in CWY. Generally tablets containing the modified\nDioscorea starches gave faster (p < 0.05) disintegration times and produced an initial\nburst release to provide the loading dose of the drug from the immediate-release layer\nfollowed by sustained release (300 Ã?± 7.56ââ?¬â??450 Ã?± 11.55 min). The correlation coefficient\n(R2) and chi-square (?2) test were employed as error analysis methods to determine the\nbest-fitting drug release kinetic equations. In vitro dissolution kinetics generally followed\nthe Higuchi and Hixson-Crowell models via a non-Fickian diffusion-controlled release.\nCarboxymethylated white yam starch and acid-modified bitter yam starch could serve as\ncheaper alternative excipients in bilayer tablet formulations for immediate and sustained\nrelease of drugs respectively, particularly where high mechanical strength is required....
The challenge in orally disintegrating tablets (ODTs) production encompasses the compromise between\ninstantaneous disintegration and sufficient physico-mechanical properties, therefore the aim of this\nstudy was to evaluate the influence of selected disintegrants on the characteristics of ODTs\nmanufactured using novel ready-to-use excipients (Ludiflash�® or Parteck�®) by direct compression\nmethod. Effect of selected disintegrants (croscarmellose sodium, microcrystalline cellulose and four\ntypes of crospovidone) on hardness, friability, wetting time, in vitro and in vivo disintegration time,\nroughness and stability parameters has been studied. The prepared tablets were also evaluated for\nsurface morphology and pore structure. 3% w/w addition of all examined disintegrants enabled\nobtaining tablets showing physico-mechanical properties that are suitable for ODTs, but disintegration\ntimes < 30 s were observed only in formulations with crospovidones. The surface of Ludiflash�® and\nParteck�® ODTs was relatively homogenous dispersion with pores, cracks and fissures. Formulations\nwith Ludiflash�® showed both less porous textures with low specific surface area (BET values up to 0.77\nm2/g) and shorter wetting and disintegration times. The optimized formulation containing superfine\ncrospovidone and Ludiflash�® (L2) or Parteck�® (P2) was found to be stable, had a pleasant mouth feel\nand disintegrated in the oral cavity within only 10 and 26 s, respectively....
The aim of this study was to describe the mechanical and sorption features of homogeneous and composite membranes which\nconsist of microcrystalline chitosan (MCCh) and fibrin (Fb) in various proportions as well as the in vitro kinetics of platelet-derived\ngrowth factor-BB (PDGF-BB) released fromten types of membranes in the presence or absence of amoxicillin (Am).Thefilms were\ncharacterized by Fourier transform infrared (FTIR) spectroscopy, mechanical tests: breaking strength (Bs) and elongation at break\n(Eb), as well as SEMimages, and swelling study.The influence of the formof samples (dry or wet) on Young�s modulus (E) was also\nexamined.The homogeneous MCCh (M1) and composite M3 and M4 (MCCh : Fb = 2 : 1 and 1 : 1) membranes were characterized\nby good sorption properties and higher mechanical strength, when compared with Fb (M2) membrane. Connecting MCCh with\nFb decreases release of PDGF-BB and increases release of Am. The most efficient release of PDGF-BB was observed in the case of\nM4 (the optimum MCCh : Fb ratio was 1 : 1) membrane. It was found that the degree of PDGF-BB release from the membrane is\ninfluenced by the physicochemical and mechanical characteristics of the films and by its affinity to growth factor PDGF-BB....
Native jackfruit seed starch (JFS) contains 30% w/w type II resistant starch (RS2) and can potentially be developed as a new\ncommercial source of RS for food and pharmaceutical application. Heat-moisture treatment (HMT) was explored as a mean to\nincrease RS content of native JFS. The effect of the conditions was tested at varied moisture contents (MC), temperatures, and\ntimes. Moisture levels of 20ââ?¬â??25%, together with temperatures 80ââ?¬â??110?C, generally resulted in increases of RS amount. The highest\namount of RS (52.2%) was achieved under treatment conditions of 25% MC and 80?C, for 16 h (JF-25-80-16). FT-IR peak ratio at\n1047/1022 cm?1 suggested increases in ordered structure in severalHMT-JFS samples with increased RS. SEM showed no significant\nchange in the granule appearance, except at high moisture/temperature treatment. XRD revealed no significant change in peaks\nintensities, suggesting the crystallinity within the granule was mostly retained. DSC showed increases in Tg and, in most cases, ?H,\nas the MC was increased in the samples. Slight but significant decreases in ?T were observed in samples with low RS, indicating\nthat a combination of high moisture and temperature might cause partial gelatinization. HMT-JFS with higher RS exhibited less\nswelling, while the solubility remained mostly unchanged....
Background: Nonviral polymeric delivery systems are explored to enhance clinical development of nucleic acids as therapeutic entities for effective management of debilitating conditions such as cancer. This study was to compare safety and efficacy of quaternary amine-containing methacrylate polymer EudragitÃ?® RL PO (ERL) and poly[N-(2-hydroxypropyl)methacrylamide]-poly(N,N-dimethylaminoethylmethacrylate) copolymer (pHPMA-b-pDMAEMA), which contains secondary and tertiary amines, as effective gene carriers.\n\nMethods: Polyplexes of pAcGFP1-C1 with ERL or pHPMA-b-pDMAEMA were fabricated at different N/P ratios. Formation of DNA/catiomer nanostructures was monitored by ethidium bromide intercalation and agarose gel retardation. Particle size, zeta potential and cytotoxicity of different polyplexes were characterized. Transfection efficiency in presence and absence of serum was assessed using confocal microscopy.\n\nResults: pHPMA-b-pDMAEMA demonstrated at least a 10-fold greater DNA condensation capacity per weight unit than ERL. However, DNA intercalation with pHPMA-b-pDMAEMA was reduced in presence of serum-free cell culture media, whereas polyplex formation with ERL was equivalent in phosphate-buffered saline, pH 7.4 and serum-free cell culture media. Cellular safety of HeLa cells was not compromised by polyplexes fabricated with either polymer up to N/P=4. However, ERL alone was more toxic. In absence of serum, pHPMA-b-pDMAEMA polyplexes at N/P=4 induced equivalent transgene expression as control TurboFectââ??¢ polyplexes. In contrast, ERL-containing nanoassemblies failed to produce measurable transgene expression. Inclusion of serum significantly decreased transfection efficiency of pHPMA-b-pDMAEMA-containing polyplexes by ~30% at N/P=4 and ~50% at N/P=2.\n\nConclusion: Polyplexes fabricated with secondary and tertiary amine-containing pHPMA-b-pDMAEMA copolymer represent more effective gene delivery systems than nanoassemblies composed of quaternary amine-containing ERL and should be further explored for clinical applications....
In present investigation attempt was made to improve dissolution profile of pioglitazone HCl using xanthan gum (XG) and modified xanthan gum (MXG) as carriers by solid dispersion technique. The XG and MXG were characterized for viscosity, swelling index and water retention capacity. Solid dispersion was prepared by kneading method using XG and MXG in ratio of 1:1, 1:2 and 1:3 respectively. The solubility data showed that solubility of pioglitazone HCl was increased with XG and found high with MXG. The FTIR, DSC and XRD studies were done. The XRD study showed crystalline nature of pure drug which was converted into amorphous form in solid dispersion. The optimized formulations X4 and M4 showed higher in-vitro drug release 85.37% and 99.21% respectively in 120 min and higher absorption against pure pioglitazone HCl. It was concluded that MXG could be a novel approach in enhancing solubility of drug....
The physical properties of pharmaceutical powders/granules are very important in the development of\noral solid dosage forms. The aim of this paper was, in a first stage, to carry out an evaluation of the flow properties\n(angle of repose, flow time, compaction capacity, compressibility index, Carr index and Hausner ratio) of\ntechnological or primary excipients of tablets (microcrystalline cellulose and dibasic calcium phosphate dihydrate)\nwhich behave differently during compaction, either pure and in binary mixtures, whose composition varied between\n20% (w/w) and 80% (w/w) at intervals of 20% (w/w). In a second stage, using an instrumented eccentric tableting\nmachine, energies and exerted forces during compaction of these materials were measured and the compressibility\ncurves were registered. In addition, plasticity index and lubrication coefficient were calculated and weight\nuniformity, thickness, hardness and tensile strength of the manufactured tablets were also evaluated. The obtained\nresults demonstrated that the binary mixtures and the pure excipients showed similar flow properties. On the other\nhand, the obtained tablets with the plastic excipient had lower values of exerted force by the upper punch and\napparent net energy, and higher values of plasticity index and time periods of the force/time compression profiles....
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