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Detpon Preechagoon Viroj Sumyai Suvatna Chulavatnatol Poj Kulvanich Thanee Tessiri Khanittha Tontisirin Thaned Pongjanyakul Verawan Uchaipichat Sirikul Aumpon Chaiyasit Wongvipaporn 《AAPS PharmSciTech》2010,11(3):1449-1455
The objectives of this study were to develop morphine sulfate sustained-release tablet formulations and to evaluate the bioequivalence
compared with a commercial brand. The physicochemical properties of the formulated and commercial tablets were determined
and compared. The bioequivalence investigation was carried out in 15 healthy male volunteers who received a single dose in
a randomized two-way crossover design. After dosing, serial blood samples were collected for a period of 24 h. Morphine concentration
was assayed by high-performance liquid chromatography with electrochemical detector. The log-transformed C
max and AUCs were statistically compared by analysis of variance, and the 90% confidence intervals (CIs) of the ratio of the log-transformed
C
max and AUCs between the most promising developed formulation and the commercial product were determined. It was found that the dissolution
rate profile of a developed formulation was similar to the commercial brand. Their similarity and difference factors were
well within limits. In the bioequivalence study, the AUClast and AUCinf between the test and the reference products were not statistically different (p = 0.227 and p = 0.468, respectively), with the 90% CIs of 83.4–102.6% and 87.7–139.4%, respectively. However, the C
max of the two formulations was significantly different (p = 0.019). The 90% CI of the developed formulation was 72.0–93.0% compared to the commercial product. In vitro dissolution of locally prepared morphine sulfate sustained-release tablets was comparable to commercial brand. However, the
results justified the conclusion of lack of bioequivalence of the developed product to the commercial one. 相似文献
2.
Hydroxypropyl methylcellulose (HPMC) tablets containing nicotine-magnesium aluminum silicate (NCT-MAS) complex particles and pH modifiers, namely, sodium chloride, citric acid, and magnesium hydroxide, were prepared using the direct compression method. The effects of HPMC viscosity grades and pH modifiers on NCT release and permeation of the matrix tablets were examined. The results showed that the higher the viscosity grade of HPMC that was used in the tablets, the lower was the unidirectional NCT release rate found. The unidirectional NCT permeation was not affected by the viscosity grade of HPMC because the NCT diffusion through the mucosal membrane was the rate-limiting step of the permeation. Incorporation of magnesium hydroxide could retard NCT release, whereas the enhancement of unidirectional NCT release was found in the tablets containing citric acid. Citric acid could inhibit NCT permeation due to the formation of protonated NCT in the swollen tablets at an acidic pH. Conversely, the NCT permeation rate increased with the use of magnesium hydroxide as a result of the neutral NCT that formed at a basic microenvironmental pH. The swollen HPMC tablets, with or without pH modifiers, gave sufficient adhesion to the mucosal membrane. Furthermore, the addition of magnesium hydroxide to the matrix tablets was the major factor in controlling buccal delivery of NCT. This study suggests that the NCT-MAS complex-loaded HPMC tablets, which contained magnesium hydroxide, are potential buccal delivery systems of NCT. 相似文献
3.
Worawut Kriangkrai Satit Puttipipatkhachorn Pornsak Sriamornsak Thaned Pongjanyakul Srisagul Sungthongjeen 《AAPS PharmSciTech》2014,15(6):1357-1369
Tackiness caused by the gas-entrapped membrane (Eudragit®RL 30D) was usually observed during storage of the effervescent floating tablets, leading to failure in floatation and sustained release. In this work, common anti-tacking agents (glyceryl monostearate (GMS) and talc) were used to solve this tackiness problem. The impact of anti-tacking agent on the properties of free films and corresponding floating tablets was investigated. GMS was more effective than talc in reducing tackiness of the film. Addition and increasing amount of anti-tacking agents lowered the film mechanical strength, but the coating films were still strong and flexible enough to resist the generated gas pressure inside the floating tablet. Wettability and water vapor permeability of the film decreased with increasing level of anti-tacking agents as a result of their hydrophobicity. No interaction between anti-tacking agents and polymer was observed as confirmed by Fourier transform infrared spectroscopy, powder X-ray diffractometry, and differential scanning calorimetry studies. Increasing amount of anti-tacking agents decreased time to float and tended to retard drug release of the floating tablets. Floating properties and drug release were also influenced by type of anti-tacking agents. The obtained floating tablets still possessed good floating properties and controlled drug release even though anti-tacking agent had some effects. The results demonstrated that the tackiness problem of the floating tablets could be solved by incorporating anti-tacking agent into the gas-entrapped membrane.KEY WORDS: anti-tacking agent, coating film, controlled release, effervescent floating tablets, Eudragit®RL 30D 相似文献
4.
Nicotine (NCT) buccal tablets consisting of sodium alginate (SA) and nicotine–magnesium aluminum silicate (NCT–MAS) complexes
acting as drug carriers were prepared using the direct compression method. The effects of the preparation pH levels of the
NCT–MAS complexes and the complex/SA ratios on NCT release, permeation across mucosa, and mucoadhesive properties of the tablets
were investigated. The NCT–MAS complex-loaded SA tablets had good physical properties and zero-order release kinetics of NCT,
which indicate a swelling/erosion-controlled release mechanism. Measurement of unidirectional NCT release and permeation across
porcine esophageal mucosa using a modified USP dissolution apparatus 2 showed that NCT delivery was controlled by the swollen
gel matrix of the tablets. This matrix, which controlled drug diffusion, resulted from the molecular interactions of SA and
MAS. Tablets containing the NCT–MAS complexes prepared at pH 9 showed remarkably higher NCT permeation rates than those containing
the complexes prepared at acidic and neutral pH levels. Larger amounts of SA in the tablets decreased NCT release and permeation
rates. Additionally, the presence of SA could enhance the mucoadhesive properties of the tablets. These findings suggest that
SA plays the important role not only in controlling release and permeation of NCT but also for enhancing the mucoadhesive
properties of the NCT–MAS complex-loaded SA tablets, and these tablets demonstrate a promising buccal delivery system for
NCT. 相似文献
5.
Zhang XH Kangsamaksin T Chao MS Banerjee JK Chasin LA 《Molecular and cellular biology》2005,25(16):7323-7332
We have previously formulated a list of approximately 2,000 RNA octamers as putative exonic splicing enhancers (PESEs) based on a statistical comparison of human exonic and nonexonic sequences (X. H. Zhang and L. A. Chasin, Genes Dev. 18:1241-1250, 2004). When inserted into a poorly spliced test exon, all eight tested octamers stimulated splicing, a result consistent with their identification as exonic splicing enhancers (ESEs). Here we present a much more stringent test of the validity of this list of PESEs. Twenty-two naturally occurring examples of nonoverlapping PESEs or PESE clusters were identified in six mammalian exons; five of the six exons tested are constitutively spliced. Each of the 22 individual PESEs or PESE clusters was disrupted by site-directed mutagenesis, usually by a single-base substitution. Eighteen of the 22 disruptions (82%) resulted in decreased splicing efficiency. In contrast, 24 control mutations had little or no effect on splicing. This high rate of success suggests that most PESEs function as ESEs in their natural context. Like most exons, these exons contain several PESEs. Since knocking out any one of several could produce a severalfold decrease in splicing efficiency, we conclude that there is little redundancy among ESEs in an exon and that they must work in concert to optimize splicing. 相似文献
6.
The purpose of this work was to investigate the effect of different polysulfonate resins and direct compression fillers on
physical properties of multiple-unit sustained-release dextromethorphan (DMP) tablets. DMP resinates were formed by a complexation
of DMP and strong cation exchange resins, Dowex 50 W and Amberlite IRP69. The tablets consisted of the DMP resinates and direct
compression fillers, such as microcrystalline cellulose (MCC), dicalcium phosphate dihydrate (DCP), and spray-dried rice starch
(SDRS). Physical properties of tablets, such as hardness, disintegration time, and in vitro release, were investigated. A
good performance of the tablets was obtained when MCC or SDRS was used. The use of rod-like and plate-like particles of Amberlite
IRP69 caused a statistical decrease in tablet hardness, whereas good tablet hardness was obtained when spherical particle
of Dowex 50 W was used. The plastic deformation of the fillers, such as MCC and SDRS, caused a little change in the release
of DMP. A higher release rate constant was found in the tablets containing DCP and Dowex 50 W, indicating the fracture of
the resinates under compression, which was attributable to the fragmentation of DCP. However, the release of DMP from the
tablets using Amberlite IRP69 was not significantly changed because of the higher degree of cross-linking of the resinates,
which exhibited more resistance to deformation under compression. In conclusion, the properties of polysulfonate resin, such
as particle shape and degree of cross-linking, and the deformation under compaction of fillers affect the physical properties
and the drug release of the resinate tablets.
Published: September 30, 2005. 相似文献
7.
The aims of the present study were to characterize the flow behavior and thixotropic properties of sodium alginate-magnesium
aluminum silicate (SA-MAS) composite gels with various ratios of SA and MAS, and to investigate the drug diffusivity and microviscosity
of the composite gels. Moreover, interaction of SA and MAS in the form of dry composite was examined by using Fourier Transform
Infrared (FTIR), and a possible structure model of SA-MAS composite gel was illustrated. Incorporating MAS into the SA gels
provided higher viscosity and changed the flow behavior from Newtonian to pseudoplastic with thixotropy. This was due to the
formation of electrostatic force and inter-molecular hydrogen bonding between SA and MAS, leading to a denser matrix structure
of the composite gels. Increasing the content of MAS decreased the drug diffusivity but increased the microviscosity of the
composite gels. The denser matrix structure of the composite gels had a higher tortuosity, resulting in slower drug diffusion
through water-filled channels in the gels. This finding suggested that incorporating MAS into the SA gels could improve the
flow behavior and sustain drug release from the gels because of the formation of a matrix structure between SA and MAS in
the gels.
Published: September 7, 2007 相似文献
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9.
The aims of this study were to characterize the morphology and size of flocculates and the zeta potential and rheological
properties of polymer–magnesium aluminum silicate (MAS) composite dispersions and to investigate the physical properties of
acetaminophen (ACT) suspensions prepared using the composite dispersions as a flocculating/suspending agent. The polymers
used were sodium alginate (SA), sodium carboxymethylcellulose (SCMC), and methylcellulose (MC). The results showed that SA,
SCMC, and MC could induce flocculation of MAS by a polymer-bridging mechanism, leading to the changes in the zeta potential
of MAS and the flow properties of the polymer dispersions. The microscopic morphology and size of the flocculates was dependent
on the molecular structure of the polymer, especially ether groups on the polymer side chain. The residual MAS from the flocculation
could create a three-dimensional structure in the SA–MAS and SCMC–MAS dispersions, which brought about not only an enhancement
of viscosity and thixotropic properties but also an improvement in the ACT flocculating efficiency of polymers. The use of
polymer–MAS dispersions provided a higher degree of flocculation and a lower redispersibility value of ACT suspensions compared
with the pure polymer dispersions. This led to a low tendency for caking of the suspensions. The SCMC–MAS dispersions provided
the highest ACT flocculating efficiency, whereas the lowest ACT flocculating efficiency was found in the MC–MAS dispersions.
Moreover, the added MAS did not affect ACT dissolution from the suspensions in an acidic medium. These findings suggest that
the polymer–MAS dispersions show good potential for use as a flocculating/suspending agent for improving the rheological properties
and physical stability of the suspensions. 相似文献
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