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1.
An oral sustained release dosage form of cinnarizine HCl (CNZ) based on gastric floating matrix tablets was studied. The release
of CNZ from different floating matrix formulations containing four viscosity grades of hydroxypropyl methylcellulose, sodium
alginate or polyethylene oxide, and gas-forming agent (sodium bicarbonate or calcium carbonate) was studied in simulated gastric
fluid (pH 1.2). CNZ release data from the matrix tablets were analyzed kinetically using Higuchi, Peppas, Weibull, and Vergnaud
models. From water uptake, matrix erosion studies, and drug release data, the overall release mechanism can be explained as
a result of rapid hydration of polymer on the surface of the floating tablet and formation of a gel layer surrounding the
matrix that controls water penetration into its center. On the basis of in vitro release data, batch HP1 (CNZ, HPMC-K100LV, SBC, LTS, and MgS) was subjected to bioavailability studies in rabbits and was
compared with CNZ suspension. It was concluded that the greater bioavailability of HP1 was due to its longer retention in
the gastric environment of the test animal. Batch no. HP1 of floating tablet in rabbits demonstrated that the floating tablet
CNZ could be a 24-h sustained release formulation. 相似文献
2.
Nathaya Wattanakorn Panida Asavapichayont Jurairat Nunthanid Sontaya Limmatvapirat Srisagul Sungthongjeen Doungdaw Chantasart Pornsak Sriamornsak 《AAPS PharmSciTech》2010,11(2):743-751
The objective of this study was to prepare and evaluate the pectin-based dosage form for buccal adhesion. Carbenoxolone sodium,
which is used for the treatment of aphthous ulcers in oral cavity, was used as a model drug. The pectin buccal discs were
prepared by direct compression. The water uptake and erosion of pectin disc increased progressively with the swelling time.
The bioadhesion of dried pectin discs decreased when either the discs were hydrated or the buccal tissue was wet with a small
volume of medium. The influencing factors such as pectin type, pectin to lactose ratio, and sweetener type on the formulations
were investigated. The results demonstrated that buccal discs prepared from pectin with a high degree of esterification (DE)
showed a weaker and more friable characteristic than that with low DE. Decreasing pectin to lactose ratio resulted in the
high dissolution rate with low bioadhesive properties. Addition of sweetener in the formulations also affected the hardness,
friability, and bioadhesive properties of the discs. The pectin discs containing sweetening agent showed a higher drug release
than those without sweetener. The results suggested that pectin-based bioadhesive discs could be used to deliver carbenoxolone
sodium in oral cavity. 相似文献
3.
Ali Kadivar Behnam Kamalidehghan Hamid Akbari Javar Ehsan Taghizadeh Davoudi Nurul Dhania Zaharuddin Bahareh Sabeti Lip Yong Chung Mohamed Ibrahim Noordin 《PloS one》2015,10(6)
Introduction
Imatinib mesylate is an antineoplastic agent which has high absorption in the upper part of the gastrointestinal tract (GIT). Conventional imatinib mesylate (Gleevec) tablets produce rapid and relatively high peak blood levels and requires frequent administration to keep the plasma drug level at an effective range. This might cause side effects, reduced effectiveness and poor therapeutic management. Therefore, floating sustained-release Imatinib tablets were developed to allow the tablets to be released in the upper part of the GIT and overcome the inadequacy of conventional tablets.Methodology
Floating sustained-release Imatinib mesylate tablets were prepared using the wet granulation method. Tablets were formulated using Hydroxypropyl Methylcellulose (HPMC K4M), with Sodium alginate (SA) and Carbomer 934P (CP) as release-retarding polymers, sodium bicarbonate (NaHCO3) as the effervescent agent and lactose as a filler. Floating behavior, in vitro drug release, and swelling index studies were conducted. Initial and total drug release duration was compared with a commercial tablet (Gleevec) in 0.1 N HCl (pH 1.2) at 37 ± 0.5°C for 24 hours. Tablets were then evaluated for various physical parameters, including weight variation, thickness, hardness, friability, and drug content. Consequently, 6 months of physical stability studies and in vitro gastro-retentive studies were conducted.Results and Discussion
Statistical data analysis revealed that tablets containing a composition of 14.67% w/w HPMC K4M, 10.67%, w/w Na alginate, 1.33%, w/w Carbomer 934P and 9.33%, w/w NaHCO3 produced the most favorable formulation to develop 24-hour sustained-release tablets with optimum floating behavior and satisfactory physicochemical characteristics. Furthermore, in vitro release study revealed that the formulated SR tablet had significantly lower Cmax and higher Tmax compared to the conventional tablet (Gleevec). Thus, formulated SR tablets preserved persistent concentration of plasma up to 24 hours.Conclusion
In conclusion, in order to suggest a better drug delivery system with constant favorable release, resulting in optimized absorption and less side effects, formulated CP-HPMC-SA based imatinib mesylate floating sustained-release tablets can be a promising candidate for cancer chemotherapy. 相似文献4.
Namfa Sermkaew Kamonthip Wiwattanawongsa Wichan Ketjinda Ruedeekorn Wiwattanapatapee 《AAPS PharmSciTech》2013,14(1):321-331
Novel self-microemulsifying floating tablets were developed to enhance the dissolution and oral absorption of the poorly water-soluble tetrahydrocurcumin (THC). Their physicochemical properties and THC permeability across Caco-2 cell monolayers were assessed. The self-microemulsifying liquid containing THC was adsorbed onto colloidal silicon dioxide, mixed with HPMC, gas-generating agents (sodium bicarbonate and tartaric acid), lactose and silicified-microcrystalline cellulose and transformed into tablets by direct compression. The use of different types/concentrations of HPMC and sodium bicarbonate in tablet formulations had different effects on the floating characteristics and in vitro THC release. The optimum tablet formulation (F2) provided a short floating lag time (∼23 s) together with a prolonged buoyancy (>12 h). About 72% of THC was released in 12 h with an emulsion droplet size in aqueous media of 33.9 ± 1.0 nm while that of a self-microemulsifying liquid was 29.9 ± 0.3 nm. The tablet formulation was stable under intermediate and accelerated storage conditions for up to 6 months. The THC released from the self-microemulsifying liquid and tablet formulations provided an approximately three- to fivefold greater permeability across the Caco-2 cell monolayers than the unformulated THC and indicated an enhanced absorption of THC by the formulations. The self-microemulsifying floating tablet could provide a dosage form with the potential to improve the oral bioavailability of THC and other hydrophobic compounds.KEY WORDS: Caco-2 cells, controlled release, permeability, self-microemulsifying floating tablets, tetrahydrocurcumin 相似文献
5.
This study compared the release behavior of single-unit (tablets, capsules) and multiple-unit (minitablets in capsules) controlled-release
systems of furosemide. The swelling and erosion behaviors of these systems, which contained the swellable hydrophilic polymers
sodium alginate (high viscosity) and Carbopol 974P, were compared. Swelling and erosion experiments showed a high degree of
swelling and limited erosion for the Carbopol preparations, whereas less swelling but greater erosion was observed for the
sodium alginate preparations. The sodium alginate preparations were eroded in 6 hours, while Carbopol preparations exhibited
limited erosion within this period of time. These results appear to be attributed to the physicochemical characteristics of
the polymers used in this study. Polymer characteristics greatly influenced the release of furosemide (model drug) from the
formulations prepared and tested. Sodium alginate had a less pronounced sustained release effect compared with Carbopol (ie,
in 8 hours all 3 sodium alginate dosage forms displayed complete release of furosemide, while only 30% of the drug was released
from Carbopol dosage forms). Finally, all 3 Carbopol dosage forms (single- and multiple-unit) displayed similar release behavior
while sodium alginate dosage forms displayed a different and more distinctive behavior. Minitablets and tablets showed a greater
sustained release effect compared with capsules. Evaluation of the release data indicates that the release mechanism for sodium
alginate formulations may be attributed to erosion/dissolution, while for Carbopol it may be attributed mainly to polymer
relaxation and diffusion of the drug from the polymer surface. 相似文献
6.
Ramji Anil Kumar Arza Chandra Sekhara Rao Gonugunta Prabhakar Reddy Veerareddy 《AAPS PharmSciTech》2009,10(1):220-226
Drugs that have narrow absorption window in the gastrointestinal tract (GIT) will have poor absorption. For these drugs, gastroretentive drug delivery systems offer the advantage in prolonging the gastric emptying time. Swellable, floating, and sustained release tablets are developed by using a combination of hydrophilic polymer (hydroxypropyl methylcellulose), swelling agents (crospovidone, sodium starch glycolate, and croscarmelose sodium) and effervescent substance (sodium bicarbonate). Formulations are evaluated for percentage swelling, in vitro drug release, floating lag time, total duration of floating, and mean residence time (MRT) in the stomach. The drug release of optimized formulation follows the Higuchi kinetic model, and the mechanism is found to be non-Fickian/anomalous according to Krosmeyer–Peppas (n value is 0.68). The similarity factor (f 2) is found to be 26.17 for the optimized formulation, which the release is not similar to that of marketed produced (CIFRAN OD®). In vivo nature of the tablet at different time intervals is observed in the radiographic pictures of the healthy volunteers and MRT in the stomach is found to be 320?±?48.99 min (n?=?6). A combination of HPMC K100M, crospovidone, and sodium carbonate shows the good swelling, drug release, and floating characters than the CIFRAN OD®. 相似文献
7.
The aim of this study was to characterize the swelling and floating behaviors of gastroretentive drug delivery system (GRDDS) composed of hydroxyethyl cellulose (HEC) and sodium carboxymethyl cellulose (NaCMC) and to optimize HEC/NaCMC GRDDS to incorporate three model drugs with different solubilities (metformin, ciprofloxacin, and esomeprazole). Various ratios of NaCMC to HEC were formulated, and their swelling and floating behaviors were characterized. Influences of media containing various NaCl concentrations on the swelling and floating behaviors and drug solubility were also characterized. Finally, release profiles of the three model drugs from GRDDS formulation (F1-4) and formulation (F1-1) were examined. Results demonstrated when the GRDDS tablets were tested in simulated gastric solution, the degree of swelling at 6 h was decreased for each formulation that contained NaCMC in comparison to those in de-ionized water (DIW). Of note, floating duration was enhanced when in simulated gastric solution compared to DIW. Further, the hydration of tablets was found to be retarded as the NaCl concentration in the medium increased resulting in smaller gel layers and swelling sizes. Dissolution profiles of the three model drugs in media containing various concentrations of NaCl showed that the addition of NaCl to the media affected the solubility of the drugs, and also their gelling behaviors, resulting in different mechanisms for controlling a drug’s release. The release mechanism of the freely water-soluble drug, metformin, was mainly diffusion-controlled, while those of the water-soluble drug, ciprofloxacin, and the slightly water-soluble drug, esomeprazole, were mainly anomalous diffusion. Overall results showed that the developed GRDDS composed of HEC 250HHX and NaCMC of 450 cps possessed proper swelling extents and desired floating periods with sustained-release characteristics. 相似文献
8.
Supriya S. Shidhaye Pritesh V. Thakkar Neha M. Dand Vilasrao J. Kadam 《AAPS PharmSciTech》2010,11(1):416-424
The purpose of this study was to develop and optimize formulations of mucoadhesive bilayered buccal tablets of pravastatin sodium using carrageenan gum as the base matrix. The tablets were prepared by direct compression method. Polyvinyl pyrrolidone (PVP) K 30, Pluronic® F 127, and magnesium oxide were used to improve tablet properties. Magnesium stearate, talc, and lactose were used to aid the compression of tablets. The tablets were found to have good appearance, uniform thickness, diameter, weight, pH, and drug content. A 23 full factorial design was employed to study the effect of independent variables viz. levels of carrageenan gum, Pluronic F 127 and PVP K30, which significantly influenced characteristics like in vitro mucoadhesive strength, in vitro drug release, swelling index, and in vitro residence time. The tablet was coated with an impermeable backing layer of ethyl cellulose to ensure unidirectional drug release. Different penetration enhancers were tried to improve the permeation of pravastatin sodium through buccal mucosa. Formulation containing 1% sodium lauryl sulfate showed good permeation of pravastatin sodium through mucosa. Histopathological studies revealed no buccal mucosal damage. It can be concluded that buccal route can be one of the alternatives available for the administration of pravastatin sodium. 相似文献
9.
Release Mechanisms Behind Polysaccharides-Based Famotidine Controlled Release Matrix Tablets 总被引:1,自引:0,他引:1
Enas M. Elmowafy Gehanne A. S. Awad Samar Mansour Abd El-Hamid A. El-Shamy 《AAPS PharmSciTech》2008,9(4):1230-1239
Polysaccharides, which have been explored to possess gelling properties and a wide margin of safety, were used to formulate
single-unit floating matrix tablets by a direct compression technique. This work has the aim to allow continuous slow release
of famotidine above its site of absorption. The floating approach was achieved by the use of the low density polypropylene
foam powder. Polysaccharides (κ-carrageenan, gellan gum, xyloglucan, and pectin) and blends of polysaccharides (κ-carrageenan
and gellan gum) and cellulose ethers (hydroxypropylmethyl cellulose, hydroxypropylcellulose, sodium carboxymethyl cellulose)
were tried to modulate the release characteristics. The prepared floating tablets were evaluated for their floating behavior,
matrix integrity, swelling studies, in vitro drug release studies, and kinetic analysis of the release data. The differential scanning calorimetry and Fourier transform
infrared spectroscopy studies revealed that changing the polymer matrix system by formulation of polymers blends resulted
in formation of molecular interactions which may have implications on drug release characteristics. This was obvious from
the retardation in drug release and change in its mechanistics. 相似文献
10.
The effect of the concentration of hydrophilic (hydroxypropyl methylcellulose [HPMC]) and hydrophobic (hydrogenated castor
oil [HCO]) products, fillers (lactose and dibasic calcium phosphate), and buffers (sodium bicarbonate, calcium carbonate,
and sodium citrate) on naproxen release rate was studied. Matrix tablets were prepared by double compression, andIn vitro dissolution tests were performed. The dissolution results showed that an increased amount of HPMC or hydrogenated castor
oil resulted in reduced drug release. The inclusion of buffers in the HPMC matrix tablets enhanced naproxen release. For HCO
tablets, only sodium bicarbonate enhanced naproxen release. The presence of lactose on HPMC matrix tablets did not show a
significantly different result from that obtained with the formulation containing dibasic calcium phosphate as a filler. However,
for the tablets containing HCO, the presence of lactose significantly enhanced the naproxen release rate. The matrix-forming
materials in this study were suitable for use in sustained-release tablets containing naproxen. The drug release can be modulated
by adding suitable amounts of diluents and buffers. 相似文献
11.
The purpose of this research was to prepare a floating drug delivery system of diltiazem hydrochloride (DTZ). Floating matrix
tablets of DTZ were developed to prolong gastric residence time and increase its bioavailability. Rapid gastrointestinal transit
could result in incomplete drug release from the drug delivery system above the absorption zone leading to diminished efficacy
of the administered dose. The tablets were prepared by direct compression technique, using polymers such as hydroxypropylmethylcellulose
(HPMC, Methocel K100M CR), Compritol 888 ATO, alone or in combination and other standard excipients. Sodium bicarbonate was
incorporated as a gas-generating agent. The effects of sodium bicarbonate and succinic acid on drug release profile and floating
properties were investigated. A 32 factorial design was applied to systematically optimize the drug release profile. The amounts of Methocel K100M CR (X1) and Compritol 888 ATO (X2) were selected as independent variables. The time required for 50% (t50) and 85% (t85) drug dissolution were selected as dependent variables. The results of factorial design indicated that a high level of both
Methocel K100M CR (X1) and Compritol 888 ATO (X2) favors the preparation of floating controlled release of DTZ tablets. Comparable release profiles between the commercial
product and the designed system were obtained. The linear regression analysis and model fitting showed that all these formulations
followed Korsmeyer and Peppas model, which had a higher value of correlation coefficient (r). While tablet hardness had little or no effect on the release kinetics and was found to be a determining factor with regards
to the buoyancy of the tablets.
Published: September 7, 2007 相似文献
12.
The objective of the present study was to develop once-daily sustained-release matrix tablets of nicorandil, a novel potassium
channel opener used in cardiovascular diseases. The tablets were prepared by the wet granulation method. Ethanolic solutions
of ethylcellulose (EC), Eudragit RL-100, Eudragit RS-100, and polyvinylpyrrolidone were used as granulating agents along with
hydrophilic matrix materials like hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose, and sodium alginate.
The granules were evaluated for angle of repose, bulk density, compressibility index, total porosity, and drug content. The
tablets were subjected to thickness, diameter, weight variation test, drug content, hardness, friability, and in vitro release
studies. The granules showed satisfactory flow properties, compressibility, and drug content. All the tablet formulations
showed acceptable pharmacotechnical properties and complied with in-house specifications for tested parameters. According
to the theoretical release profile calculation, a oncedaily sustained-release formulation should release 5.92 mg of nicorandil
in 1 hour, like conventional tablets, and 3.21 mg per hour up to 24 hours. The results of dissolution studies indicated that
formulation F-I (drug-to-HPMC, 1∶4; ethanol as granulating agent) could extend the drug release up to 24 hours. In the further
formulation development process, F-IX (drug-to-HPMC, 1∶4; EC 4% wt/vol as granulating agent), the most successful formulation
of the study, exhibited satisfactory drug release in the initial hours, and the total release pattern was very close to the
theoretical release profile. All the formulations (except F-IX) exhibited diffusion-dominated drug release. The mechanism
of drug release from F-IX was diffusion coupled with erosion. 相似文献
13.
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
14.
The purpose of this research was to study mucoadhesive bilayer buccal tablets of propranolol hydrochloride using the bioadhesive
polymers sodium alginate (Na-alginate) and Carbopol 934P (CP) along with ethyl cellulose as an impermeable backing layer.
The tablets were evaluated for weight variation, thickness, hardness, friability, surface pH, mucoadhesive strength, swelling
index, in vitro drug release, ex vivo drug permeation, ex vivo mucoadhesion, and in vivo pharmacodynamics in rabbits. Tablets
containing Na-alginate and CP in the ratio of 5∶1 (F2) had the maximum percentage of in vitro drug release without disinte-gration
in 12 hours. The swelling index was proportional to Na-alginate content and inversely proportional to CP content. The surface
pH of all tablets was found to be satis-factory (7.0±1.5), close to neutral pH; hence, buccal cavity irritation should not
occur with these tablets. The mechanism of drug release was found to be non-Fickian diffusion and followed zero-order kinetics.
The formulation F4 was optimized based on good biodhesive strength (28.9±0.99 g) and sustained in vitro drug permeation (68.65%±3.69%
for 12 hours). The behavior of formulation F4 was examined in human saliva, and both the drug and the buccal tablet were found
to be stable. The formulation F4 was applied to rabbit oral mucosa for in vivo studies. The formulation inhibited isoprenaline-induced
tachycardia. The studies conducted in rabbits confirmed the sustained release as compared with intravenous administration.
Published: September 21, 2007 相似文献
15.
The purpose of this research was to prepare floating microspheres consisting of (1) calcium silicate as porous carrier; (2)
orlistat, an oral anti-obesity agent; and (3) Eudragit S as polymer, by solvent evaporation method and to evaluate their gastro-retentive
and controlled-release properties. The effect of various formulation and process variables on the particle morphology, micromeritic
properties, in vitro floating behavior, percentage drug entrapment, and in vitro drug release was studied. The gamma scintigraphy
of the optimized formulation was performed in albino rabbits to monitor the transit of floating microspheres in the gastrointestinal
tract. The orlistat-loaded optimized formulation was orally administered to albino rabbits, and blood samples collected were
used to determine pharmacokinetic parameters of orlistat from floating microspheres. The microspheres were found to be regular
in sphae and highly porous. Microsphere formulation CS4, containing 200 mg calcium silicate, showed the best floating ability
(88%±4% buoyancy) in simulated gastric fluid as compared with other formulations. Release pattern of orlistat in simulated
gastric fluid from all floating microspheres followed Higuchi matrix model and Peppas-Korsmeyer model. Prolonged gastric residence
time of over 6 hours was achieved in all rabbits for calcium silicate-based floating microspheres of orlistat. The enhanced
elimination half-life observed after pharmacokinetic investigations in the present study is due to the floating nature of
the designed formulations. 相似文献
16.
李劲鸿 《现代生物医学进展》2008,8(1):116-117
目的:制备洛索洛芬钠混合性缓释片并考察其体外释放度.方法:采用混合骨架材料制备洛索洛芬钠混合性缓释片.以硬脂酸为骨架材料,并以药物在222 nm的波长处的吸收度为指标考察不同比例的硬脂酸、乙基纤维素、羟丙基甲基纤维素及乳糖对洛索洛芬钠释放速率和影响因素进行考察,确定最优处方.结果:在一定范围内,随着硬脂酸量的减少,乳糖和HPMC含量增加,片剂的累积释放量增加.制备的缓释片可以持续释放药物12小时.结论:制备的洛索洛芬钠混合性缓释片缓释效果良好. 相似文献
17.
The purpose of this study is to characterize the inter-grade and inter-batch variability of sodium alginate used in the formulation of matrix tablets. Four different grades and three batches of one grade of sodium alginate were used to prepare matrix tablets. Swelling, erosion, and drug release tests of sodium alginate matrix tablets were conducted in a USP dissolution apparatus. Substantial differences in swelling and erosion behavior of sodium alginate matrix tablets were evident among different viscosity grades. Even different batches of the same grade exhibit substantial differences in the swelling and erosion behavior of their matrix tablets. The erosion behavior of sodium alginate matrix tablets can be partly explained by their rheological properties (both apparent viscosity and viscoelasticity) in solution. Sodium alginate with higher apparent viscosity and viscoelasticity in solution show slower erosion rate and higher swelling rate. Compacts prepared from grades or batches with higher viscosity and higher viscoelasticity show slower drug release. For grades or batches with similar apparent viscosities, apparent viscosities of sodium alginate solution at low concentration alone are not sufficient to predict the functionality of sodium alginate in matrix tablets. Viscoelastic properties of sodium alginate solutions at one high concentration corresponding to the polymer gel state, may be suitable indicia of the extended release behavior of sodium alginate matrix tablets. 相似文献
18.
The purpose of this investigation was to study the anti-inflammatory activities of both glycerrhitinic acid (GA) and the aqueous
licorice extract (ALE) in comparison with diclofenac sodium (DS) (10 mg/kg), using the carrageenan-induced paw edema model
in male albino rats. In addition, the anti-ulcer activities of ALE, famotidine (FT), and a combination of ALE and FT using
indomethacin-induced ulceration technique in rat stomach were investigated. Conventional DS tablets containing GA, as well
as DS chewable tablets containing either GA or ALE with different tastes were prepared. Also, rapidly disintegrating FT tablets
were prepared using direct compression and camphor sublimation methods. ALE or GA produced significant anti-inflammatory activity
similar to DS, and when taken concomitantly, there is no possible antagonism. The anti-ulcer activity of licorice was found
to be similar to that of FT in indomethacin-induced ulceration technique in rat stomach. Combination therapy of both FT and
licorice showed higher anti-ulcer activity than either of them alone. Generally, tablets containing the crosslinked sodium
carboxymethyl cellulose (AcDisol) showed more rapidly disintegrating effect than those including Sodium starch glycolate (Primojel).
The oral disintegration was very rapid for all the tested formulations. Also, the amount of FT absorbed from the oral cavity
was nearly 9 from 10 mg theoretically present in each formula. It could be concluded that both GA and ALE have anti-inflammatory
activity comparable with DS. It may be recommended to add ALE to either FT or diclofinac for more effective anti-inflammatory
or anti-ulcer formulations, respectively. 相似文献
19.
Different hydroxypropyl methylcellulose (HPMC)/anhydrous dibasic calcium phosphate (ADCP) matrix tablets have been developed aiming to evaluate the influence of both components ratio in the control release of a water-soluble drug (theophylline). In order to characterise the matrix tablets, swelling, buoyancy and dissolution studies have been carried out in different aqueous media (demineralised water, progressive pH medium, simulated gastric fluid, simulated intestinal fluid and simulated colonic fluid). The HPMC/ADCP ratio has turned out to be the determinant in the matrix behaviour: the HPMC characteristic swelling behaviour was modulated, in some cases, by the ADCP characteristic acidic dissolution. When the HPMC/ADCP ratio was ≥0.69, buoyancy, continuous swelling and low theophylline dissolution rate from the matrices (H1, H2 and H3) were observed in all dissolution media. Consequently, these formulations could be adequate as gastro-retentive drug delivery systems. Additionally, HPMC/ADCP ratio ≤0.11 (H5 and H6) induces a pH-dependent drug release which could be applied to design control drug release enteric formulations (with a suitable enteric coating). Finally, a HPMC/ADCP ratio between 0.11 and 0.69 (H4) yield a gastrointestinal controlled drug release, due to its time-dependent buoyancy (7 h) and a total drug delivery in 17 h in simulated colonic fluid.Key words: anhydrous dibasic calcium phosphate, hydroxypropyl methylcellulose, matrix tablets, oral controlled release, theophylline 相似文献
20.
The aim of this investigation was preparation and comparative evaluation of fabricated matrix (FM), osmotic matrix (OM), and
osmotic pump (OP) tablets for controlled delivery of diclofenac sodium (DS). All formulations were evaluated for various physical
parameters, and in vitro studies were performed on USP 24 dissolution apparatus II in pH 7.4 buffer and distilled water. In
vivo studies were performed in 6 healthy human volunteers; the drug was assayed in plasma using HPLC, and results were compared
with the performance of 2 commercial tablets of DS. Various pharmacokinetic parameters (ie, Cmax, Tmax, area under the curve [AUC0–24], and mean residence time) and relative bioavailability were compared. All fabricated formulations showed more prolonged
and controlled DS release compared with commercial tablets studied. The OM and OP tablets, however, performed better than
the matrix tablets. The rate and extent of drug release from FM1 matrix tablets (single polymer) was significantly different
from that of FM2 (admixed polymers). Type of porosigenic agents and osmogens also influenced the drug release. Analysis of
in vitro data by regression coefficient analysis revealed zero-order release kinetics for OM and OP tablets, while FM tablets
exhibited Higuchi kinetics. In vivo results indicated prolonged blood levels with delayed peak and improved bioavailability
for fabricated tablets compared to commercial tablets. It was concluded that the osmotic matrix and osmotic pump tablets could
provide more prolonged, controlled, and gastrointestinal environmental-independent DS release that may result in an improved
therapeutic efficacy and patient compliance. 相似文献