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1.
A dual drug-loaded hydroxypropylmethylcellulose (HPMC) matrix tablet simultaneously containing drug in inner tablet core and outer coated layer was formulated using drug-containing aqueous-based polymeric Eudragit RS30D dispersions. Effects of coating levels, drug loadings in outer layers, amount and type of five plasticizers and talc concentration on the release characteristics were evaluated on the characteristics in simulated gastric fluid for 2 h followed by a study in intestinal fluids. Melatonin (MT) was selected as a model drug. The surface morphology of dual drug-loaded HPMC tablets using scanning electron microscope (SEM) was smooth, showing the distinct coated layer with about 75-microm coating thickness at the 15% coating level. Unlike the uncoated and conventionally coated HPMC tablet, the dual drug-loaded HPMC matrix tablet gave a biphasic linear release, showing a zero-order for 4 h (first) followed by another zero-order release when fitted using linear regression (r(2) = 0.99). As the coating levels (15, 25%) increased, the release rate was further decreased. The biphasic release profiles of dual drug-loaded HPMC matrix tablet was unchanged except when 25% coating level containing 0.5% drug concentration was applied. As the drug concentration in polymeric coating dispersion increased (0.25-1.0%), the amount of drug released increased. The time for the first linear release was also advanced. However, the biphasic release pattern was not changed. The biphasic release profiles of dual drug-loaded HPMC matrix tablet were highly modified, depending on the amount and type of five plasticizers. Talc (10-30%) in coating dispersion as an anti-sticking material did not affect the release profiles. The current dual drug-loaded HPMC matrix tablet, showing biphasic release profiles may provide an alternative to deliver drugs with circadian rhythmic behaviors in the body but needs to be further validated in future in human studies. The dual drug-loaded coating method is also interesting for the modified release of poorly water-soluble drugs because solubilizers and other additives can be added in drug-containing polymeric coating dispersions.  相似文献   

2.
This study attempted to characterize the influence of core and coating formulations on the release profiles to establish in vitro/in vivo correlations of pulsatile pattern for a pulsatile drug delivery system activated by membrane rupture based on three core tablet formulations (A-core: HPMC 50+4000cps, B-core: E10M, and C-core: K100M) coated with various thicknesses of a semipermeable ethylcellulose membrane plasticized with HPMC 606 (Pharmacoat 606) at different ratios with/without adding various amounts of water to dissolve it in the coating solution. Drug release behaviors were investigated using apparatus II in four media of pH 1.2 solution, pH 6.8 buffer, deionized water, and a NaCl solution rotated at 75, 100, and 150rpm. Pilot studies of the in vivo pharmacokinetics were conducted as well for comparison with the in vitro results. Results demonstrated that drug release from the three kinds of core tablets in deionized water increased with an increasing stirring rate, and decreased with an increasing viscosity grade of HPMC used in the core formulations. A significant promotion of drug release from core tablets was observed for the three levels of NaCl media in comparison with that in deionized water. Results further demonstrated that a slightly slower release rate in pH 1.2 solution and a faster release rate in pH 6.8 buffer than that in deionized water were observed for the A-core and B-core tablets, with the former being slower than the latter. However, similar release rates in the three kinds of media were observed for C-core tablets, but they were slower than those for the A- and B-core tablets. Dissolution of coated tablets showed that the controlling membrane was ruptured by osmotic pressure and swelling which activated drug release with a lag time. The lag time was not influenced by the pH value of the release medium or by the rotation speeds. The lag time increased with a higher coating level, but decreased with the addition of the hydrophilic plasticizer, Pharmacoat 606, and of the water amount in the coating solution. The lag time also increased with a higher concentration of NaCl in the medium. The release rate after the lag time was determined by the extent of retardation of gelation of HPMC in the core tablet based on the ionic strength of the medium. Results of the three pilot crossover studies for the exemplified pulsatile systems indicated that the lag time for the in vivo plasma profile was well correlated with that determined from the in vitro release profile in pH 1.2 solution and the in vivo release rate was better reflected by that performed in pH 6.8 buffer.  相似文献   

3.
Effect of solvents on physical characteristics and release characteristics of monolithic acetaminophen (APAP) hydroxypropylmethylcellulose (HPMC) matrix granules and tablets were examined. Various types and amounts of solvents were employed for granulation and cOAting. APAP and other excipients were mixed and were then wet-granulated in a high-speed mixer. The dried granules were then directly compressed and film-coated with low viscosity grade HPMC. As the amount of water increased, the size of granules also increased, showing more spherical and regular shape. However, manufacturing problems such as capping and lamination in tableting occurred when water was used alone as a granulating solvent. The physical properties of HPMC matrix granules were not affected by the batch size. The initial release rate as well as the amount of APAP dissolved had a tendency to decrease as the water level increased. Addition of nonaqueous solvent like ethanol to water resulted in good physical properties of granules. When compared to water/ethanol as a coating solvent, the release rate of film-coated HPMC matrix tablets was more sensitive to the conditions of coating and drying in methylene chloride/ethanol. Most of all, monolithic HPMC matrix tablet when granulated in ethanol/water showed dual release with about 50% drug release immediately within few minutes followed by extended release. It was evident that the type and amount of solvents (mainly water and ethanol) were very important for wet granulation and film-coating of monolithic HPMC matrix tablet, because the plastic deforming and fragmenting properties of material were changed by the different strengths of the different solvents.  相似文献   

4.
目的 制备盐酸地尔硫 (diltiazamhydrochloride,DIL)延迟起释型缓释片 ,解析释药机制 ,并考察外衣层组成对药物释放的影响。方法 用干压包衣技术制备盐酸地尔硫的延缓片 ,用释药时滞 (Tlag)及释药速率常数 (k)将各因素 (外衣层中的HPMC用量和粘度 ,PVPK30用量、EC粘度及压片压力 )对药物的释放效果进行评价。结果HPMC用量或粘度增大 ,Tlag延长 ,k减慢 ;PVPK30用量增大 ,Tlag减短 ,k加快 ;在一定范围内EC粘度及压片压力波动对释药行为无影响。结论 延缓片中药物主要是通过溶蚀机制释放 ,外衣层的溶蚀速率是决定释药时滞的关键因素。  相似文献   

5.
Hydrogel compression-coated tablets are able to release the core drug after a period of lag time and have potential for colon-specific drug delivery based on gastrointestinal transit time concept. This study investigated the factors influencing in vitro release characteristics of a model drug 5-fluorouracil from hydroxypropylmethycellulose (HPMC) compression-coated tablets. The core tablet, prepared by a wet granulation compression method, was designed to disintegrate and dissolute quickly. To prepare the compression-coated tablets, 50% of the HPMC/lactose coat powder was precompressed first, followed by centering the core tablet and compressing with the other 50% of the coat powder. Release characteristics were evaluated in distilled water by using a Chinese Pharmacopoeia rotatable basket method. Effect of HPMC viscosity, lactose content in outer shell, and overall coating weight of outer shell on release lag time (T(lag)), and zero-order release rate (k) were studied. Release of drug from compression-coated tablets began after a time delay as a result of hydrogel swelling/retarding effect, followed by zero-order release for most of the formulations studied. HPMC of higher viscosity (K4M and K15M) provided better protection of the drug-containing core, showing increased release lag time and slower release rate. Incorporating lactose in outer shell led to decrease of T(lag) and increase of k. T(lag) and k are exponentially and linearly correlated to lactose content, expressed as weight percentage of the outer shell. Larger coating weight (W) of outer shell produced larger coating thickness (D) around core tablet, which resulted in increase in T(lag) and decrease in k. There was good fitting of a linear model for each of the four variables W, D, T(lag), and k. Hardness of the compression-coated tablets and pHs of the release media had little effect on drug release profile. It is concluded that the release lag time and release rate are able to be tailored through adjusting the formulation variables to achieve colon-specific drug delivery of 5-fluorouracil.  相似文献   

6.
替硝唑结肠给药系统的研制   总被引:7,自引:0,他引:7  
依据时控型结肠给药系统原理,以替硝唑为模型药物.利用于压包衣和薄膜包衣双层包衣的方法制备了结肠给药系统,并对影响药物释放的因素(如EC粒度,HPMC粘度,时控层厚度,片刑硬度等)、肠衣层性能和药物释放稳定性等进行了考查。结果表明,HPMC粘度增加使药物释放滞后时间延长,但高粘度HPMC会导致药物释放无明显突跃点;包芯片硬度40~60N、片重0.26~0.28g的片剂药物释放较稳定。加速试验(3个月)结果表明,药物释放稳定性良好。  相似文献   

7.
本文制备了盐酸维拉帕米(verapamil hydrochloride, VH)的三层片芯及四层片芯杯形片, 分别达到脉冲控释双相释药及双脉冲多相释药。用混合粉末直接压片法制备多层片芯, 干压包衣技术制备盐酸维拉帕米杯形片, 以释药时滞(Tlag)评价杯形片顶层重量、 羟丙基甲基纤维素HPMC用量及压片压力对药物的释放效果。结果表明, 顶层重量增加及HPMC用量增大时, Tlag延长; 压片压力在6~10 kg·cm-2时, 压力增大, 时滞延长。杯形片中药物主要通过顶层单面释药, 阻滞层(顶层及多层片芯中的缓释层)的溶蚀速率是决定释药时滞的关键因素。  相似文献   

8.
盐酸地尔硫延迟起释型缓释片的研制   总被引:7,自引:1,他引:6  
张宁  朱家壁 《药学学报》2002,37(9):724-727
目的制备盐酸地尔硫(diltiazam hydrochloride,DIL)延迟起释型缓释片,解析释药机制,并考察外衣层组成对药物释放的影响。方法用干压包衣技术制备盐酸地尔硫的延缓片,用释药时滞(Tlag)及释药速率常数(k)将各因素(外衣层中的HPMC用量和粘度,PVP K30用量、EC粘度及压片压力)对药物的释放效果进行评价。结果 HPMC用量或粘度增大,Tlag延长,k减慢;PVP K30用量增大,Tlag减短,k加快;在一定范围内EC粘度及压片压力波动对释药行为无影响。结论延缓片中药物主要是通过溶蚀机制释放,外衣层的溶蚀速率是决定释药时滞的关键因素。  相似文献   

9.
Hydrogel compression-coated tablets are able to release the core drug after a period of lag time and have potential for colon-specific drug delivery based on gastrointestinal transit time concept. This study investigated the factors influencing in vitro release characteristics of a model drug 5-fluorouracil from hydroxypropylmethycellulose (HPMC) compression-coated tablets. The core tablet, prepared by a wet granulation compression method, was designed to disintegrate and dissolute quickly. To prepare the compression-coated tablets, 50% of the HPMC/lactose coat powder was precompressed first, followed by centering the core tablet and compressing with the other 50% of the coat powder. Release characteristics were evaluated in distilled water by using a Chinese Pharmacopoeia rotatable basket method. Effect of HPMC viscosity, lactose content in outer shell, and overall coating weight of outer shell on release lag time (Tlag), and zero-order release rate (k) were studied. Release of drug from compression-coated tablets began after a time delay as a result of hydrogel swelling/retarding effect, followed by zero-order release for most of the formulations studied. HPMC of higher viscosity (K4M and K15M) provided better protection of the drug-containing core, showing increased release lag time and slower release rate. Incorporating lactose in outer shell led to decrease of Tlag and increase of k. Tlag and k are exponentially and linearly correlated to lactose content, expressed as weight percentage of the outer shell. Larger coating weight (W) of outer shell produced larger coating thickness (D) around core tablet, which resulted in increase in Tlag and decrease in k. There was good fitting of a linear model for each of the four variables W, D, Tlag, and k. Hardness of the compression-coated tablets and pHs of the release media had little effect on drug release profile. It is concluded that the release lag time and release rate are able to be tailored through adjusting the formulation variables to achieve colon-specific drug delivery of 5-fluorouracil.  相似文献   

10.
Bearing in mind the present scenario of the increasing biological tolerance of bacteria against antibiotics, a time controlled two pulse dosage form of amoxicillin was developed. The compression coating inlay tablet approach was used to deliver the drug in two pulses to different parts of the GIT after a well defined lag time between the two releases. This was made possible by formulating a core containing one of the two drug fractions (intended to be delivered as the second pulse), which was spray coated with a suspension of ethyl cellulose and a hydrophilic but water insoluble agent as a pore former (microcrystalline cellulose). Coating of up to 5% (m/m) was applied over the core tablet, giving a corresponding lag of 3, 5, 7 and 12 h. Increasing the level of coating led to retardation of the water uptake capacity of the core, leading to prolongation of the lag time. Microcrystalline cellulose was used as a hydrophilic but water insoluble porosity modifier in the barrier layer, varying the concentration of which had a significant effect on shortening or prolongation of the lag time. This coated system was further partially compression coated with the remaining drug fraction (to be released as the first immediate release pulse) with a disintegrant, giving a final tablet. The core tablet and the final two pulse inlay tablet were further investigated for their in vitro performance.  相似文献   

11.

Introduction

In this study, we present the development of a chronomodulated delivery system consisting of a fast-swelling tablet core containing montelukast sodium coated with a blend of different ratios of ethyl cellulose (gastrointestinal tract (GIT)-insoluble polymer) and Eudragit L100 (enteric polymer). Montelukast sodium is a leukotriene receptor antagonist commonly prescribed for patients of asthma and allergic rhinitis. Asthma and allergic rhinitis share a common core pathophysiology and have almost similar temporal pattern in their occurrence or exacerbation of their respective symptoms, suggesting a role for chronotherapy.

Methods

The developed formulation was optimized statistically using central composite design to achieve desired release profile. The coated tablets were studied for water uptake, bursting time, and in vitro release study.

Results

The bursting time (lag time) of coated tablet was affected by the pH of buffer, molarity of ions, and concentration of different types of surfactant in dissolution media. With increasing percentage of Eudragit L100 in coating composition, the lag time decreased and release rates significantly increased—could be attributed due to increase in water uptake and polymer leaching. As expected, with increasing coating level, lag time increased and release rate decreased due to the increased diffusion pathways. In vivo study revealed comparative pharmacokinetic profiles of core tablets and pulsatile release tablets (PRTs); however, T max of 2 h for core tablets and 6 h for PRTs were observed.

Conclusion

Thus, designed PRTs were found to be suitable in treating episodic attack of asthma in early morning and associated allergic rhinitis.  相似文献   

12.
Enteric coated HPMC capsules designed to achieve intestinal targeting.   总被引:6,自引:0,他引:6  
The enteric coating of HPMC capsules containing paracetamol was investigated. Two enteric polymers, Eudragit L 30 D-55 and Eudragit FS 30 D were studied, which are designed to achieve enteric properties and colonic release, respectively. The capsules were coated in an Accela Cota 10, and, as shown by optical microscopy, resulted in capsules with a uniform coating. Scanning electron microscopy of the surface of the capsules illustrate that, in contrast to gelatin, HPMC has a rough surface, which provides for good adhesion to the coating. Dissolution studies demonstrated that capsules coated with Eudragit L 30 D-55 were gastro resistant for 2 h at pH 1.2 and capsules coated with Eudragit FS 30 D were resistant for a further 1 h at pH 6.8. The product visualisation technique of gamma scintigraphy was used to establish the in vivo disintegration properties of capsules coated with 8 mg cm(-2) Eudragit L 30 D-55 and 6 mg cm(-2) Eudragit FS 30 D. For HPMC units coated with Eudragit L 30 D-55, complete disintegration occurred predominately in the small bowel in an average time of 2.4 h post dose. For HPMC capsules coated with Eudragit FS 30 D, complete disintegration did not occur until the distal small intestine and proximal colon in an average time of 6.9 h post dose.  相似文献   

13.
A novel coated doughnut-shaped tablet is evaluated as to its ability to be manufactured in a reproducible manner, and as to whether it releases model drugs at a zero-order rate. The doughnut-shaped tablets were compressed using specially designed punches, which make automated production feasible. In the preliminary part of the experiment, HPMC K15M mixed with gelatin was found to be the most suitable coating tablet material with respect to its disintegration and adherence properties. The adherence of the coating tablet to ibuprofen cores was not optimal, so different concentrations of gelatin, to act as a plasticiser and enhance adherence, were further investigated. Friability results of the coated doughnut-shaped tablet indicate that coating tablets containing 20% and 30% gelatin had a percentage weight losses of less than 1% after 100 revolutions in a Roche friabilator. For all the concentrations of gelatin, the granule blends had angle of repose values in the range of 22.01-17.8 degrees. The compressibility factor, as measured from the slopes of the natural logarithm of compressional force versus crushing strength, were 121.91 +/- 2.36, 132.64 +/- 3.60, and 88.54 +/- 11.52 for the coating tablet granules containing 10%, 20%, and 30% gelatin in HPMC K15M, respectively. The composition of the coating tablet did not affect the rate of release of both caffeine and ibuprofen from the coated doughnut-shaped tablets. The coatings also adhered to the core tablets for the entire duration of the release of the drugs.  相似文献   

14.
目的制备5-氨基水杨酸微丸及其时控结肠定位控释释药系统的研究。方法首先采用挤出滚圆机制备了含药微丸,然后使用流化床包衣设备将微丸包衣,以羟丙甲纤维素和微粉硅胶的混合物包衣作为溶胀控释层,以乙基纤维素水分散体Surelease包衣作为时滞包衣层,并将包衣微丸装入肠溶胶囊。用释放度测定法研究微丸的释放行为。结果药物通过时滞层破裂开始释放,该层厚度增加可显著延长释药时滞。调节羟丙甲纤维素的型号、包衣增重及羟丙甲纤维素与微粉硅胶两者比例,可以控制药物释放速度。在模拟胃肠道pH情况下延迟5 h释药,之后的10 h内释药完全。结论可通过调整溶胀控释层包衣混合物的比例、型号、包衣厚度及时滞层的包衣厚度,制备5-氨基水杨酸时控结肠定位控释释药系统。  相似文献   

15.
The aim of the present study was to investigate the effect of hydroxypropylmethylcellulose (HPMC-2208), used as an excipient for controlled release of drug, on the release profiles and bioavailability of the poorly water-soluble nifedipine (NP) from a tablet prepared using macrogol 6000 (PEG) and HPMC. The crushing tolerance of the NP tablet prepared using PEG and HPMC (NP-PEG-HPMC tablet) was markedly increased with increasing compression force used during the preparation from 20 to 200 MPa. The values reached their maximal levels (approximately 13 kg for the NP-PEG-HPMC tablet and 8 kg for the PEG tablet) at the compression force of 100 MPa. Although NP is a poorly water-soluble drug, it was rapidly dissolved from the NP-PEG tablet (without HPMC) due to the improvement of its dissolution rate in the presence of PEG. NP dissolution was complete at the latest within 1 h. On the other hand, dissolution of NP from the NP-PEG-HPMC tablet was significantly delayed with an increase in the concentration of HPMC in the tablet. The dissolution of NP from the NP-PEG-HPMC tablet containing 50% HPMC-2208 was markedly delayed as the viscosity of HPMC also increased. Interestingly, the same peak plasma NP concentration (C(max)) and the area under the plasma NP concentration-time curve (AUC(0-10)) were observed for both the NP-PEG tablet and NP-PEG-HPMC tablets, however, the time to C(max) (t(max)) for the NP-PEG-HPMC tablet was significantly higher when the NP-PEG-HPMC tablet was orally administered to rabbits. We describe here a preparation method of a new sustained-release NP-PEG-HPMC tablet using a mixture of NP-PEG granules (prepared with PEG) and HPMC.  相似文献   

16.
The influence of disintegrant on the water uptake and subsequent disintegration force developed was investigated in a simple tablet formulation. The results indicated that a reasonable correlation existed between water uptake and disintegration force for the disintegrants screened with cross linked polyvinyl pyrrolidone (PVP XL) showing a proportionally higher disintegration force for the amount of water imbibed. Two tablet formulations, intended to promote accelerated drug release in the colon, were prepared, with and without PVP XL, and film coated with a mixture of pectin, chitosan and HPMC. The two systems showed different drug release rates which were influenced by the pH of the dissolution medium. In the presence of pectinolytic enzyme, drug release was faster when compared to release in buffer alone for both systems although the mechanism differed for each. Drug release in simulated gastrointestinal conditions showed a bimodal profile with the increased drug release rate being triggered by the action of pectinolytic enzymes.  相似文献   

17.
Khaya gum has been evaluated as a controlled release agent in modified release matrices in comparison with hydroxypropylmethylcellulose (HPMC) using paracetamol (water soluble) and indometacin (water insoluble) as model drugs. Tablets were produced by direct compression and the in-vitro drug release was assessed in conditions mimicking the gastrointestinal system. Khaya gum matrices provided a controlled release of paracetamol for up to 5 h. The release of paracetamol from khaya gum matrices followed time-independent kinetics (n = 1.042) and release rates were dependent on the concentration of the drug present in the matrix. The addition of tablet excipients not only improved the mechanical properties of the tablet, but also altered the dissolution profile, except for dicalcium phosphate where the profile remained unchanged. HPMC could be used to control the drug release rates from khaya gum matrices and a combination of khaya gum and HPMC gave zero-order time-independent release kinetics. Indometacin exhibited a lag time in excess of 2 h, due to its insolubility at low pH, before the zero-order release was observed. Thus khaya gum matrices could be useful in the formulation of sustained release tablets for up to 5 h and the appropriate combination of khaya gum and HPMC could be used to provide a time-independent release for longer periods.  相似文献   

18.
替硝唑片粘合剂的筛选   总被引:1,自引:0,他引:1  
目的筛选替硝唑片的粘合剂。方法分别采用8%聚乙烯吡咯烷酮(PVP-K30)、10%淀粉浆、40%糖浆和2.0%羟丙基甲基纤维素K4(HPMC-K4),50%乙醇作为替硝唑片的粘合剂,制成不同粘合剂配方的药片,观察素片的外观以及包衣后外观的变化,测定其硬度、脆碎度、崩解时限和溶出度。结果PVP-K30制成的片有光泽,测定脆碎度后有少许崩边缺角现象,包衣后片表面粗糙;淀粉浆制成的片有光泽,测定脆碎度后无崩边缺角现象,包衣后药片完整;糖浆制成的片较脆,测定脆碎度后有崩边、顶裂现象,包衣后片表面粗糙且有顶裂倾向;羟丙基甲基纤维素制成的片有光泽,振摇无崩边缺角现象,包衣后完整,外观好。结论用2.0%HPMC-K4、50%乙醇为粘合剂制备的药片外观好,在包薄膜衣过程中,不易出现崩边、缺角现象,包衣后片面美观,硬度、崩解度和溶出度也优于用其它粘合剂制成的片子。  相似文献   

19.
5-氨基水杨酸结肠定位给药时控微丸的制备与体外释放   总被引:24,自引:0,他引:24  
傅崇东  徐惠南  张瑜 《药学学报》2000,35(5):389-393
目的 用水分散体包衣技术制备5-氨基水杨酸结肠定位微丸给药系统。方法 以低粘度HPMC为内层溶胀材料,乙基纤维素水分散体Aquacoat为外层控释包衣材料,柠檬酸三乙酯为增塑剂,使用流化床包衣设备,制备时间控制的微丸,用释放度测定法研究微丸在不同pH介质中的释放度。结果 溶胀层的加入对制备时控微丸是必要的,药物是通过外膜破裂释放的,溶胀层厚度增加,释药时滞有一定程度的缩短,外层厚度增加以及增塑剂用量增加,可显著延长释药时滞。微丸释药随介质pH增加而加快,在模拟胃肠道pH情况下延迟5 h释药,之后10 h内释药完全。结论 通过调整内外层的包衣厚度可制备5-氨基水杨酸结肠定位给药微丸。  相似文献   

20.
Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor, primarily used for the treatment of hypertension, congestive heart failure, and heart attack. It belongs to BCS class III having a half-life of 12 hrs and 25% bioavailability. The purpose of the present work was to develop a press-coated, floating-pulsatile drug delivery system. The core tablet was formulated using the super-disintegrants crosprovidone and croscarmellose sodium. A press-coated tablet (barrier layer) contained the polymer carrageenan, xanthan gum, HPMC K4M, and HPMC K15M. The buoyant layer was optimized with HPMC K100M, sodium bicarbonate, and citric acid. The tablets were evaluated for physical characteristics, floating lag time, swelling index, FTIR, DSC, and in vitro and in vivo behavior. The 5% superdisintgrant showed good results. The FTIR and DSC study predicted no chemical interactions between the drug and excipients. The formulation containing xanthan gum showed drug retaining abilities, but failed to float. The tablet containing HPMC K15M showed a high swelling index. The lag time for the tablet coated with 200 mg carrageenan was 3±0.1 hrs with 99.99±1.5% drug release; with 140 mg HPMC K4M, the lag time was 3±0.1 hrs with 99.71±1.2% drug release; and with 120 mg HPMC K15M, the lag time was 3±0.2 hrs with 99.98±1.7% drug release. The release mechanism of the tablet followed the Korsmeyer-Peppas equation and a first-order release pattern. Floating and lag time behavior have shown good in vitro and in vivo correlations.  相似文献   

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