盐酸地尔硫延迟起释型缓释片的研制

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。     

盐酸丁螺环酮缓释片的制备及体外释放研究

目的 :为了减少给药次数和减小药物的毒副作用 ,制备盐酸丁螺环酮缓释片。方法 :采用亲水凝胶骨架材料 (HPMC)制备该缓释片 ,并考察药物与HPMC不同比例组成、HPMC不同粘度等对该水溶性药物释放的影响。结果 :药物 /HPMC之比为影响释放过程的主要因素 ,HPMC(高粘度 )的粘度与药物释放无关 ,且该骨架片的释药与释放介质的 pH无关。 结论 :该缓释片制备工艺简单 ,缓释速率可控。     

丙烯酸系列树脂在药物剂型中的应用

通过对丙烯酸树脂在薄膜包衣片、控释骨架片、固体分散体、微球、微囊、透皮给药系统和结肠定位给药等药物新剂型中的应用进行分析，认为随着丙烯酸树脂的开发研究，其在药物新剂型中的应用将越来越广泛。     

盐酸地尔硫延迟起释型缓释片的研制

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(T_lag)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,T_lag延长,k减慢;PVP K30用量增大,T_lag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。     

罗红霉素渗透泵型控释片处方工艺研究

目的：探讨罗红霉素渗透泵型控释片的处方工艺。方法：以罗红霉素（RXM）为模型药物,通过测定药物的释放度,考察促渗透剂、渗透聚合物种类及其用量、片芯硬度、释药孔径、包衣膜组成、包衣膜厚度对药物释放的影响。结果：PVP和增塑剂用量、包衣膜厚度和释药孔径对渗透泵型控释片的药物释放具有显著影响,一定范围内片芯硬度对药物释放的影响不明显。结论：选用500mg／mL的蔗糖作为渗透促进剂;200mg／mL的聚维酮-K30（PVP）为促渗透聚合物;包衣膜选用200mg／mL的PEG-6000。     

薄膜包衣中常见问题的分析及其解决方法

近几年薄膜包衣技术在固体制剂中已得到广泛应用。通过薄膜包衣可以避光、防潮和隔离空气以增加药物的稳定性 ;掩盖药物的不良味道 ,便于患者服用 ;控制药物的释放部位和释放速度 ;防止药物的配伍变化 ;提高片剂的外观形态等。还具有工序少、时间短、能耗低、片剂增重少等优点。薄膜衣片的质量主要取决于片芯的组成和质量、包衣液的处方、包衣操作条件、包装及贮存条件等。片芯的组成和质量主要体现在片芯的活性成分和各赋形剂及片芯的外观、硬度、脆碎片、片型等。包衣液的处方中通常含有高分子聚合物、增塑剂、染色剂、溶剂等 ,而包衣的操…     

奥沙西罗包衣控释片的制备及其质量评价

目的制备奥沙西罗包衣控释片,考察处方组成和工艺因素对制剂质量及体外释药行为的影响,并分析其释药机制。方法以乙基纤维素(EC-45cP)为骨架材料、乙基纤维素(EC-10cP)为成膜材料、聚乙二醇6000(PEG6000)为增塑剂,采用滚转包衣锅包衣,药物作为致孔剂控制药物释放,考察处方因素,片芯制备和包衣工艺等对制剂质量及体外释放行为的影响。结果片芯骨架材料用量、致孔剂用量、增塑剂用量、包衣厚度等因素对药物释放有明显影响。制剂体外释药行为符合零级动力学方程。结论薄膜包衣法制得奥沙西罗控释片,调整处方组成可获得12 h平稳释药的制剂。     

卡托普利延迟起释型缓释片的研制

目的 制备适用于临睡前服用，间隔4～6h后于次日凌晨开始释放药物并持续释放较长一段时间的卡托普利延缓片。方法用干压包衣技术制备卡托普利延缓片，中心组合设计优化处方，人工神经网络预测释药时滞，在SAS上进行多元线性回归，并对优化结果进行验证，从而确定衣层处方。然后以卡托普利缓释片为对照制剂，以相似因子f2为筛选指标，确定片芯组成，从而确定最终处方。结果所优化的卡托普利延缓片体外释药时滞为5h，开始释放后与对照制剂有良好的相似性(L=64．06)，体外释放符合一级动力学规律。结论以干压包衣技术制得包芯片，由衣层控制延迟释放的释药时滞，由衣层和片芯共同控制药物缓慢释放。     

包衣工艺对布地奈德结肠定位片控释衣膜的影响

目的:优化布地奈德结肠定位片控释衣膜的包衣工艺。方法:采用单因素试验考察喷枪位置、喷液速度、喷气雾化压力、片床温度、进风温度及进风流量等包衣参数对定位片微孔型半透膜和肠溶膜包衣的影响。结果:确定喷枪口离片床距离约10～20cm;微孔型半透膜及肠溶膜包衣液的喷射速度分别为3、1mL·min-1,喷气雾化压力分别为2、1.5bar(1bar=105Pa),进风温度分别为50～55、40～45℃,片床温度分别为(40±1)、(30±1)℃,进风流量分别为5、7m3·min-1;采用优化的包衣参数制得的布地奈德结肠定位片半透膜包衣增重10%,肠溶膜包衣增重5%,24h体外累积释放度为(77.5±8.6)%,释药时滞为(6.0±0.5)h。结论:优化后的包衣工艺适合布地奈德结肠定位片控释衣膜包衣。     

石杉碱甲凝胶骨架缓释片药物释放因素的研究

目的考察影响石杉碱甲(hupcrzine—A，Hup—A)亲水凝胶骨架片体外释药的各种因素。方法以羟丙基甲基纤维素(HPMC)和乙基纤维素(EC)为骨架材料，湿法制粒压片制备缓释骨架片，并考察HPMC和EC的用量、粘度、HPMC粒度、压片压力及其他辅料对石杉碱甲亲水凝胶骨架片体外释药的影响。结果石杉碱甲亲水凝胶骨架片体外释药符合Higuchi方程。HPMC粒度、粘度、压片压力及辅料种类对石杉碱甲的释放速率没有显性影响。HPMC用量及EC的粘度、用量对石杉碱甲的释放速率有显性影响。结论HPMC及EC用量、EC粘度为影响石杉碱甲亲水凝胶骨架片释放速率的主要因素。     

Release behavior and photo-image of nifedipine tablet coated with high viscosity grade hydroxypropylmethylcellulose: effect of coating conditions

An orally applicable nifedipine-loaded core tablets was coated using high viscosity grade HPMC (100,000 cps) in ethanol/water cosolvent. The release of coated tablet was evaluated using USP paddle method in 900 ml of simulated gastric fluid (pH 1.2) for 2 h followed by intestinal fluid (pH 6.8) for 10 h. The surface morphologies using scanning electron microscope and photo-images using digital camera of coated tablet during the release test were also visualized, respectively. The viscosity of hydro-alcoholic HPMC solution largely decreased as the amount of ethanol increased. There was no significant difference in viscosity among plasticizers used. The distinct and continuous coated layer was observed using scanning electron microscope. However, the surface morphologies were highly dependent on HPMC concentration and ratio of coating solvents. The higher ratio of ethanol/water gave a longer lag time prior to drug release. Lag time also increased as a function of the coating levels based on weight gains due to increased thickness of coated layer. Lag time is inversely correlated with HPMC concentration in ethanol/water (5:1) cosolvent. As the HPMC concentration slightly decreased from 3.8 to 3.2% in hydroalcoholic coating solution, a large increase of lag time was observed. As the swelling (mixing) time of high viscosity grade HPMC in ethanol/water cosolvent increased from 1 to 5 h, the release rate was decreased due to enough plasticization of polymer. Based on photo-imaging analysis, the coated tablet was initially swelled and gelled without erosion and disintegration over 5 h. The disintegration of the coated tablet was occurred approximately 7 h after dissolution, resulting in pulsed release of drug. The high viscosity grade HPMC can be applicable for polymeric coating after careful selection of solvent systems. The release behavior and lag time could be controlled by coating conditions such as HPMC concentration, ethanol/water ratio as a coating solvent, coating level and swelling (mixing) time of coating solution. The current time-controlled release tablet coated with high viscosity grade HPMC with a designated lag time followed by a rapid release may provide an alternative to site specific or colonic delivery of drugs. In addition, the release behavior can be matched with body's circadian rhythm pattern in chronotherapy.     

5-氨基水杨酸时控结肠定位控释微丸及其制剂的研制

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。     

复方丹参脉冲控释片的制备及体外释放度考察

目的:选用高分子材料制备复方丹参(CD)脉冲控释片,并进行体外释放度考察。方法:采用干包衣控释法制备CD脉冲控释片,应用HPLC法进行体外释放度考察。结果:HPMC用量或黏度增大,释药时滞延长;稀释剂用量增大,释药时滞缩短;在包衣处方组成比例不变的情况下,包衣层用量增加,释药时滞延长。结论:CD脉冲控释片能实现体外定时脉冲释药,并可通过调整处方实现不同时滞的控释效果。     

Effect of formulation variables on drug and polymer release from HPMC-based matrix tablets

The objective of this work was to assess the effect of two formulation variables, hydroxypropylmethylcellulose (HPMC)/lactose ratio and HPMC viscosity grade, on the release of a model drug and HPMC, as well as the mechanism of drug release from HPMC-based matrix tablets. A water-soluble compound, adinazolam mesylate, was used as the model drug. Both drug and HPMC release were found to be a function of the formulation variables, with higher drug and HPMC release rates for formulations with lower HPMC/lactose ratios and lower HPMC viscosity grades. However, the K15M and K100M formulations had identical drug release profiles. All the drug release data fit well to the Higuchi expression. By comparing the drug and HPMC release data, it was concluded that diffusion of drug through the hydrated gel layer was the predominant drug release mechanism for most of the formulations studied.     

Formulation of biphasic release tablets containing slightly soluble drugs.

A new biphasic release system for slightly soluble drugs has been proposed. To enhance the dissolution rate, the drug was milled with a superdisintegrant. Then, double-layer tablets were prepared. One layer was formulated to release the drug in a very short time (fast-release). The other consisted of an extended-release hydroxypropylmethylcellulose (HPMC) matrix. Different HPMC concentrations (10, 16 and 22%) and viscosity grades (Methocel K4, K15 and K100M) were used to obtain different release rates of the drug from the extended-release layer, ketoprofen and praziquantel were used as slightly soluble model drugs.The in vitro dissolution tests of the prepared double-layer systems, showed the desired biphasic behaviour: the drug contained in the fast releasing layer dissolved within the first 15 min, while the drug contained in the prolonged-release layer was released at different times, depending on the formulation of the hydrophilic matrix. In particular, an increase in the percentage and viscosity grade of HPMC, in the extended release layer, leads to a decrease in the drug delivery rate and produces a wide range of different release rates from only a few hours up to 24 h.     

Oral controlled release formulations of rifampicin. Part II: Effect of formulation variables and process parameters on in vitro release

Hydrophilic controlled release matrix tablets of rifampicin, a poorly soluble drug, have been formulated using hydroxypropyl methylcellulose (HPMC) polymer (low, medium, and high viscosity) by direct compression method. Influence of formulation variables and process parameters such as drug:HPMC ratio, viscosity grade of HPMC, drug particle size, and compression force on the formulation characters and drug release has been studied. Our results indicated that the release rate of the drug and the mechanism of release from the HPMC matrices are mainly controlled by the drug:HPMC ratio and viscosity grade of the HPMC. In general, decrease in the drug particle size decreased the drug release. Lower viscosity HPMC polymer was found to be more sensitive to the effect of compression force than the higher viscosity. The formulations were found to be stable and reproducible.     

Modified release from hydroxypropyl methylcellulose compression-coated tablets

The goal of this study was to obtain flexible extended drug release profiles (e.g., sigmoidal, pulsatile, increasing/decreasing release rates with time) with hydroxypropyl methylcellulose (HPMC) compression-coated tablets. Drugs of varying solubility (carbamazepine, acetaminophen, propranolol HCl and chlorpheniramine maleate) were incorporated into the tablet core in order to evaluate the flexibility/limitations of the compression-coated system. The HPMC-compression-coating resulted in release profiles with a distinct lag time followed by different release phases primarily determined by the drug solubility. Carbamazepine, a water-insoluble drug, was released in a pulsatile fashion after a lag time only after erosion of the HPMC compression-coat, while the more soluble drugs were released in a sigmoidal fashion by diffusion through the gel prior to erosion. With carbamazepine, increasing the molecular weight of HPMC significantly increased the lag time because of the erosion-based release mechanism, while, in contrast, molecular weight did not affect the release of the more soluble drugs. The lag-time and the release rate could also be well controlled by varying the HPMC amount in and the thickness of the compression-coating. A pulsatile release could also be achieved for water-soluble drugs by introducing an enteric polymer coating between the drug core and the HPMC compression-coating. This novel concept of introducing an enteric subcoating eliminated drug diffusion through the gelled HPMC layer prior to its erosion. Incorporating drug in the compression-coating in addition to the tablet core in varying ratios resulted in release profiles with increasing, decreasing or constant release rates. In conclusion, a versatile single-unit delivery system for a wide range of drugs with great flexibility in release profiles was presented.     

Formulation parameters affecting the performance of coated gelatin capsules with pulsatile release profiles

The objective of this study was to develop and evaluate a rupturable pulsatile drug delivery system based on soft gelatin capsules with or without a swelling layer and an external water-insoluble but -permeable polymer coating, which released the drug after a lag time (rupturing of the external polymer coating). The swelling of the gelatin capsule itself was insufficient to rupture the external polymer coating, an additional swelling layer was applied between the capsule and the polymer coating. Croscarmellose sodium (Ac-Di-Sol) was more effective as a swelling agent than low and high molecular weight hydroxypropylmethyl cellulose (HPMC; E5 or K100M). Brittle polymers, such as ethyl cellulose (EC) and cellulose acetate propionate (CAPr), led to a better rupturing and therefore more complete drug release than the flexible polymer coating, Eudragit RS. The lag time of the release system increased with higher polymer coating levels and decreased with the addition of a hydrophilic pore-former, HPMC E5 and also with an increasing amount of the intermediate swelling layer. The water uptake of the capsules was linear until rupture and was higher with CAPr than with EC. Soft gelatin capsule-based systems showed shorter lag times compared to hard gelatin capsules because of the higher hardness/filling state of the soft gelatin capsules. The swelling pressure was therefore more directed to the external polymer coating with the soft gelatin capsules. Typical pulsatile drug release profiles were obtained at lower polymer coating levels, while the release was slower and incomplete at the higher coating levels. CAPr-coated capsules resulted in a more complete release than EC-coated capsules.     

Mixed Polymer Coating for Modified Release from Coated Spheroids

Modified-release drug spheroids coated with an aqueous mixture of high-viscosity hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) were formulated. The preparation of core drug spheroids and the coating procedures were performed using the rotary processor and a bottom-spray fluidized bed, respectively. Dissolution studies indicated that incorporation of suitable additives, such as poly(vinylpyrrolidone) (PVP) and poly(ethylene glycol) 400 (PEG) improved the flexibility and integrity of the coat layer by retarding the drug release. An increase in coating levels applied generally retarded the release rate of the drug. However, the ratio of HPMC to NaCMC in the mixed, plasticized polymeric coat played a more dominant role in determining the dissolution T_50% values. The optimal ratio of HPMC to NaCMC for prolonged drug release was found to be 3:1, whereas an increase in the amount of NaCMC in the mixed polymer coat only increased drug release. The synergistic viscosity effect of HPMC and NaCMC in retarding drug release rate was greater in distilled water than in dissolution media of pH 1 and 7.2. Cross-sectional view of the scanning electron micrograph showed that all of the coated spheroids exhibited a well-fused, continuous, and distinct layer of coating film. The drug release kinetics followed a biexponential first-order kinetic model.     

Mixed polymer coating for modified release from coated spheroids

Modified-release drug spheroids coated with an aqueous mixture of high-viscosity hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) were formulated. The preparation of core drug spheroids and the coating procedures were performed using the rotary processor and a bottom-spray fluidized bed, respectively. Dissolution studies indicated that incorporation of suitable additives, such as poly(vinylpyrrolidone) (PVP) and poly(ethylene glycol) 400 (PEG) improved the flexibility and integrity of the coat layer by retarding the drug release. An increase in coating levels applied generally retarded the release rate of the drug. However, the ratio of HPMC to NaCMC in the mixed, plasticized polymeric coat played a more dominant role in determining the dissolution T50% values. The optimal ratio of HPMC to NaCMC for prolonged drug release was found to be 3:1, whereas an increase in the amount of NaCMC in the mixed polymer coat only increased drug release. The synergistic viscosity effect of HPMC and NaCMC in retarding drug release rate was greater in distilled water than in dissolution media of pH 1 and 7.2. Cross-sectional view of the scanning electron micrograph showed that all of the coated spheroids exhibited a well-fused, continuous, and distinct layer of coating film. The drug release kinetics followed a biexponential first-order kinetic model.