Alternative method for enteric coating of HPMC capsules resulting in ready-to-use enteric-coated capsules

The aim of this study was to develop an alternative method for enteric coating of HPMC capsules that avoids the sealing step before coating, resulting in ready-to-use enteric-coated capsules for the use in retail or hospital pharmacy or R&D sections of pharmaceutical industry and for the production of enteric-coated heat and moisture sensitive biomaterials. HPMC caps and bodies 00 (Vcaps, Capsugel) were coated separately in a fluid bed apparatus prior to filling (GPCG-1, Glatt) with Eudragit^® L30D-55 or Eudragit^® FS 30 D (Röhm), Aqoat^® AS-HF (Shin-Etsu) and Sureteric^® (Colorcon), using an optimised coating process. The coated bodies were filled and closed with the coated caps without encountering problems of coating damage. The release in 0.1N HCl after 2 h from capsules coated with Eudragit^® L30D-55, Eudragit^® FS 30 D, Aqoat^® AS-HF and Sureteric^® was 0.6±0.3, 0.6±0.3, 1.2±0.2 and 7.3±1.9%, respectively. The alternative method was reproducible and offered a way to overcome the time-consuming and expensive sealing step required using the conventional coating procedure. The obtained enteric-coated HPMC capsules can be stored (un)-filled for at least 6 months without loosing enteric properties.     

Preparation and in vitro characterization of piroxicam enteric coated pellets using powder layering technique

The objective of this study was to develop piroxicam enteric coated pellets using nonpareil seeds by powder layering technique to minimize its gastrointestinal adverse effects. Inert seeds were prepared by incorporating sugar, Avicel PH 101 and lactose. The obtained cores were then treated by PVP 10 w/v % solution using centrifugal granulator (CF-granulator) and then coated with micronized piroxicam using HPMC solution (8 w/v %) as binder. The piroxicam pellets were finally coated with different polymers (Eudragit L30D-55, Eudragit L100, Eudragit NE30D, Acryleze, or mixture of Eudragits L30D-55 and NE30D) and plasticizers (triethyl citrate and polyethylene glycol 6000). Results showed that Eudragit L30D-55 with 3% weight gain accompanied with TEC produced suitable enteric coated pellets.     

In vitro evaluation of coating polymers for enteric coating and human ileal targeting

Recombinant interleukin-10 producing Lactococcus lactis is an alternative therapy for Crohn's disease. For in vivo interleukin-10 production, thymidine, the essential feed component of these recombinant bacteria should be coadministered. Different coating polymers were evaluated in vitro for enteric properties and targeting suitability to the ileum, the major site of inflammation in Crohn's disease. To guarantee ileal delivery, the polymer must dissolve from pH 6.8 and allow complete release within 40 min. Aqoat AS-HF coated pellets (15%) showed poor enteric properties and thymidine was released below pH 6.8. Eudragit FS30D coated pellets (15%) showed good enteric properties, but no thymidine was released within 40 min at pH 6.8. Eudragit S coated pellets (15%) showed good enteric properties after curing at elevated temperature while no thymidine was released within 40 min at pH 6.8. In another approach to pass the proximal small intestine intact, pellets were coated with 30% Eudragit L30D-55. At pH 6.0, they showed a lag-phase of 20 min. No influence of layer thickness was seen above pH 6.5. Alternatively, pellets were coated with a mixture of Eudragit FS30D/L30D-55 but they showed poor enteric properties and thymidine was released below pH 6.8. In conclusion, none of the tested polymers/mixtures ensured enteric properties and ileal targeting.     

Physical and enteric properties of soft gelatin capsules coated with eudragit ® L 30 D-55

The enteric coating of soft gelatin capsules (SGC) containing ibuprofen in either PEG 400 or Miglyol© was investigated. The effects of two plasticizers, triethyl citrate (TEC) and tributyl citrate (TBC), on the physical and enteric properties of SGC coated with Eudragit ® L 30 D-55 were studied. The water soluble plasticizer TEC was found to be a good plasticizing agent for the Eudragit® L 30 D-55 irrespective of the fill liquid, while the TBC provided satisfactory results only for capsules containing the hydrophobic fill liquid, Miglyol ®. The combination of TEC and TBC provided effective plasticization for the acrylic coating regardless of the fill liquid. A subcoat of HPMC showed no effect on the enteric protection of either Miglyol® - and PEG-containing capsules that were stored at room temperature and zero percent relative humidity. The moisture content of the gelatin shell of the film coated SGC stored at room temperature and at 0 or 96% relative humidity was followed as a function of time. The load strength of the capsules was measured during 3 months of storage using an Instron universal testing apparatus, and the physical-mechanical properties of the capsules were correlated with the moisture content of the SGC. As the moisture content of the gelatin decreased, all formulations exhibited an increase in load strength.     

Development of an enteric-coated, layered multi-particulate formulation for ileal delivery of viable recombinant Lactococcus lactis.

Layering of recombinant hIL-10 producing Lactococcus lactis (L. lactis Thy12) on inert carriers is a promising technique for the preparation of a multi-particulate formulation of viable, hIL-10 producing L. lactis. To improve viability after layering and storage, L. lactis Thy12 was layered in different matrices (10% skim milk and/or 2.5, 5, 10% inulin). After layering, the highest viability was obtained in the 10% skim milk supplemented with 5% inulin matrix (8.7%). However, upon storage, 10% skim milk alone yielded the highest viability. Thereby, layered L. lactis Thy12 showed superior long term stability in comparison with freeze-dried L. lactis Thy12. The layering process was performed during 3h without encountering technical problems, with good layer consistence and constant viability. Enteric properties were obtained with a 30% Eudragit L30D-55 or 15% Eudragit FS30D coating and maintained during an initial six months storage period (-20 degrees C/20% RH). After in vitro simulation of the gastric stage, only 5% of the bacteria remained viable in Eudragit L30D-55 coated pellets, contrary to 85% in Eudragit FS30D coated pellets, indicating its superior protective capacity against gastric fluid. After eight months storage (-20 degrees C), 80% of the initial L. lactis Thy12 remained viable in the Eudragit FS30D coated pellets.     

双氯芬酸钠肠溶微丸型片剂的研制

本文制备了双氯芬酸钠肠溶微丸型片剂。以丙烯酸树脂EudragitNE30D和EudragitL30D-55不同比例的混合物作为衣膜材料，对不同粒径大小的双氯芬酸钠速释丸芯进行不同增重水平的包衣，并与不同压缩特性和用量比例的缓冲微丸混合，压片。所得的双氯芬酸钠肠溶微丸型片剂在人工胃液中2 h内累积释放百分数<10%，在人工肠液中1 h内累积释放百分数为(83±2.42)%。结果表明EudragitNE30D与EudragitL30D-55以一定比例混合制备得到适合压片的肠溶微丸，硬脂酸制备的缓冲微丸可用于微丸型片剂的制备。     

离心造粒包衣法制备洛索洛芬钠缓释微丸及体外释放度考察

目的:制备洛索洛芬钠缓释微丸。方法:采用离心造粒包衣法制备洛索洛芬钠微丸。首先制备微晶纤维素空白母核和洛索洛芬钠含药素丸,并在此基础上进行丙烯酸树脂水分散体(Eudragit NE30D、Eudragit L30D-55)包衣,并对包衣微丸的释药特征进行探讨。结果:微晶纤维素(MCC)空白母核32～40目的收率约78.6%,含药素丸18～24目收率约88.2%,使用Eudragit NE30D和Eudragit L30D-55比例是20:1的包衣液,包衣增重10%。包衣干燥后,即得洛索洛芬钠缓释微丸,洛索洛芬钠缓释胶囊体外释药行为较好地符合Higuchi方程。结论:在优化的工艺条件下可制得表面光滑、圆整度高的洛索洛芬钠缓释微丸。     

SM-1小粒径肠溶微丸的制备及体外评价

目的制备SM-1小粒径肠溶微丸,并优化其处方,以达到肠溶和便于小动物给药的目的。方法采用流化床空白丸芯上药法,在丸芯表面依次包覆含药层、羟丙基甲纤维素（HPMC）隔离层和丙烯酸树脂（EudragitL30D-55）肠溶层。以载药量、耐酸性及释放度为指标,对SM-1肠溶微丸的处方进行优化。结果隔离层增重8%,肠溶层增重15%的肠溶微丸粒径〈450μm（40目筛）,圆整度良好,载药量约为20%;在pH为2.0的盐酸溶液中2 h内肠溶衣层薄层完好,药物释放度〈4%;在pH为6.8的PBS溶液中,45 min内释放度均〉70%。结论采用流化床制备SM-1肠溶微丸工艺可行,重现性好,具有良好的肠溶特性,粒径〈380μm,可用于小动物给药。     

对乙酰氨基酚肠溶小丸片的制备工艺研究和质量考察

目的:考察衣膜材料、缓冲小丸的种类以及用量对肠溶型小丸片释药行为的影响。方法:以Eudragit NE30D和FS30D分别与Eudragit L30D-55以不同比例混合后,对含有对乙酰氨基酚的小丸进行包衣。包衣小丸分别与不同的辅料混合后压制成片剂,通过比较压片小丸和未压片小丸释药曲线的相似度(f2)值,来考察包衣膜材的延伸性。同时采用铸膜法制备与包衣处方相同的游离膜,并考察游离膜的机械性能。结果:Eudragit NE30D或Eudragit FS30D与Eudragit L30D-55以2∶1,1∶1和1∶2混合包衣小丸,压成片剂和未压成片的小丸的溶出曲线f2值分别为82,70,65和70,58,41,表明EudragitNE30D和Eudragit FS30D在加入一定量的Eudragit L30D-55后仍可以保护小丸压片时不破裂。采用不同材料制备的缓冲小丸,与包衣小丸混合压片,缓冲材料的种类对片剂的溶出曲线影响不大,主要是通过影响片剂的硬度和崩解时限而影响片剂的质量。结论:Eudragit NE30D和Eudragit FS30D均有着良好的延展性,添加Eudragit L30D-55后延展性变差...     

Development and in vitro Evaluation of Enteric Coated Multiparticulate System for Resistant Tuberculosis

The multiparticulate formulation of sodium para aminosalicylate for oral administration was developed by extrusion spheronization technique. Microcrystalline cellulose was used as filler in concentration of 14.4% w/w. Pellets were coated with Eudragit L 30 D-55 using fluidized bed processor. Different weight gains of acrylic polymer were applied onto the pellets and evaluated for in vitro dissolution behavior in 0.1 N HCl for two hours and then media was changed to phosphate buffer pH 6.8. A 60% w/w coating level of Eudragit L30 D 55 has produced the most acceptable results against the gastric attack. 3% Seal coat of HPMC E5 was also applied in order to protect the drug from migration into the Eudragit coat and film coat was applied in order to prevent aggregation of pellets in the dissolution media. Morphological characteristics of developed pellets were also investigated by scanning electron microscopy and found to be smooth and spherical. Developed system was found to be suitable for the delivery of Sod PAS in to intestinal region.     

Use of enteric polymers for production of microspheres by extrusion-spheronization

To simplify the manufacture of enteric dosage forms, incorporation of enteric polymers into the matrix of phenylbutazone microspheres produced by extrusion-spheronization was compared to the coating of cores. The effect of different polymers, cellulose acetate phthalate (CAP), hydroxypropylmethyl cellulose phthalate (HPMCP) and Eudragit L100-55 and the amount of granulating liquid were evaluated for the effect of selected physical properties and drug release behavior. Using the enteric polymers in the microsphere cores showed a similar pattern of release to the coated spheres with no notable difference in drug release behavior being observed between the dosage forms. The microspheres with Eudragit L100-55 in the matrix were less friable and disintegration times were much closer to the coated microspheres than formulations including the other polymers. Variation of the amount of Eudragit L100-55 in the cores allowed optimization of disintegration and drug release profiles.     

Influence of an enteric polymer on drug release rates of theophylline from pellets coated with Eudragit RS 30D

The purpose of this research study was to investigate the influence of an enteric polymer on the drug release properties of theophylline pellets coated with Eudragit RS 30D. Theophylline pellets were coated with aqueous colloidal dispersions of Eudragit RS 30D containing various amounts of Eudragit L 100-55. The effect of storage conditions on the release of drug from coated pellets was determined as a function of the pH of the dissolution medium. The results from the dissolution study showed significant changes in the dissolution rate of theophylline from pellets coated with Eudragit RS 30D when cured at 40 degrees C for 4 days. No change in the drug release rate was observed when Eudragit L100-55 was present in the Eudragit RS 30D dispersion. Increasing the ratio of Eudragit L100-55 to Eudragit RS 30D resulted in faster drug release rates from the coated pellets. An increase in the pH of the dissolution medium was found to enhance drug release from the pellets coated with Eudragit RS 30D containing Eudragit L 100-55. Theophylline pellets when coated with Eudragit RS 30D containing the enteric polymer Eudragit L100-55 demonstrated no aging effects when stored at elevated temperatures. The overcoating of the pellets with Eudragit RD 100 did not affect the drug release profiles and prevented the particles from agglomerating during curing and storage.     

麝香保心pH依赖型梯度释药微丸的研究

目的制备麝香保心pH依赖型梯度释药微丸并进行体内外考察。方法分别以HPMC,Eudragit L-30D-55和Eudragit L100-Eudragit S100(1∶5)为包衣材料制备pH依赖型梯度释药微丸,并进行体外释放度、胃肠道转运和体内药代动力学研究。结果冰片和人参总皂苷体外释放度的f₂值为79.6,3种包衣微丸分别在胃、十二指肠和空回肠部崩解,由3种微丸组成的缓释胶囊中冰片的T_max与原丸剂相近,而C_max明显降低,相对生物利用度为96%。结论 缓释胶囊中的冰片和人参总皂苷在体外可同步缓释,在体内具有pH依赖性崩解溶散的特征,冰片作为指标性成分具有梯度缓释的药代动力学特点。     

In vitro release and in vivo absorption in beagle dogs of meloxicam from Eudragit FS 30 D-coated pellets

The objective of this study was to develop meloxicam-loaded colon-specific pellets coated with Eudragit FS 30 D and further evaluate their in vitro release and in vivo absorption in beagle dogs. Meloxicam-loaded cores (drug loading, 4.8%, w/w) were prepared by layering drug-binder (HPMC)-solubilizer (beta-cyclodextrin) solution onto nonpareils (710-850 microm) and then coated with a copolymer of methyl acrylate, methyl methacrylate and methacrylic acid (Eudragit FS 30 D). The obtained pellets with 15% (w/w) coating level had a spherical form and a smooth surface with coating thickness approximately 28 microm. The in vitro drug release from the pellets was pH-dependent with sufficient gastric resistance (pH 1.2: no release; pH 6.8: 6%; pH 7.0: 52%; pH 7.2: 100%; pH 7.4: 100%, after 3 h incubation). In vivo study was carried out using pentagastrin-pretreated beagle dogs. The onset of meloxicam absorption from the coated pellets with 15% (w/w) Eudragit FS 30 D (3.0+/-0.8 h) was significantly delayed (p<0.05) compared to that from the uncoated drug-layered cores (0.6+/-0.3 h). The area under the meloxicam plasma concentration-time curve (AUC(0-->96)(h) was not significantly different between the two preparations (p>0.05), although AUC(0-->96)(h) obtained after oral administration of coated pellets (142.5+/-59.6 microg h/ml) was lower than that obtained after administration of uncoated drug-layered cores (180.8+/-61.9 microg h/ml). These results suggested that meloxicam could be delivered to the colon with 15% (w/w) coating level of Eudragit FS 30 D and this polymer coating had no significant influence on the relative bioavailability of meloxicam of the pellets.     

盐酸青藤碱肠溶缓释微丸的制备

目的：制备盐酸青藤碱肠溶缓释微丸。方法：分别以Eudragit NE30D为缓释膜材，HPMC E5为隔离层膜材，Eudragit L30D-55为肠溶层膜材，采用流化床包衣法制备盐酸青藤碱肠溶缓释微丸，并考察缓释层、隔离层和肠溶层包衣增重对药物释放的影响。结果：制备的肠溶缓释微丸在人工胃液中释放度<10%，人工肠液中缓慢释放8 h。结论：该制备工艺简单易行，重现性好，有望应用于工业化生产。     

盐酸帕罗西汀肠溶缓释片的制备及体外释放研究

目的制备盐酸帕罗西汀肠溶缓释片,并对其体外释放度进行考察。方法采用HPMC K100LV和HPMC K4M作为骨架材料,以水乳糖为填充剂制备盐酸帕罗西汀缓释片芯,再使用Eudragit L30D-55包肠溶衣,制成盐酸帕罗西汀肠溶缓释片,并采用f_2相似因子法评价自制制剂和参比制剂在释放介质中的体外释放行为。结果体外释放度实验显示,自制制剂和参比制剂的f_2相似因子值大于50。结论制备的盐酸帕罗西汀肠溶缓释片的释药行为与参比制剂的体外释放行为相似。     

Influence of aqueous coatings on the stability of enteric coated pellets and tablets.

Pancreatin pellets, placebo pellets and tablets containing vitamin B2 were coated with various aqueous and organic enteric polymers, HPMCAS, HP, Eudragit L 100-55, Eudragit L 30 D-55, CAP, CAT, CMEC and PVAP, comparatively investigated and tested for storage stability. With the exception of Eudragit L 100-55 and Eudragit L 30 D-55, higher amounts of coating material were needed to achieve gastro-resistance with aqueous coating than with organic coating. Film formation from aqueous dispersions of micronized HP 55 was affected by the degree of micronization and was improved by reducing the particle size of the polymer. Undercoating was another suitable measure to decrease the amount of coating material required. The choice of plasticizer was of special importance in the aqueous dispersions, and type and quantity must be appropriate for the polymer applied. Non-polymeric plasticizers such as triethyl citrate (TEC) evaporated along with water during the spraying or drying process and high temperatures promoted such losses. The moisture-sensitive pancreatic enzymes were damaged both by humidity and heat during aqueous coating. The extent of damage was dependent on the coating equipment used. Upon storage, coatings obtained from aqueous dispersions showed changes in enteric performance or release characteristics as a consequence of three chemical/physical mechanisms: hydrolysis of ester linkages in the polymer or plasticizer, evaporation of the plasticizer, delayed film formation. The active ingredient pancreatin induced hydrolysis of the ester based film-former hydroxypropyl methylcellulose acetate succinate (HPMCAS). However, even without the influence of enzymes, the phthalic ester groups of aqueous hydroxypropyl methylcellulose phthalate (HP) were partly cleaved after 11 months storage. In HPMCAS-coated pancreatin pellets, the plasticizer glyceryl triacetate was almost completely hydrolyzed by the enzymes, whilst triethyl citrate was lost by evaporation through permeable packaging material at elevated temperatures. Open storage at elevated temperatures and humidities caused changes in the surface structure of HPMCAS coatings, consisting of a smoothing of the originally somewhat porous film and sticking. When applied to vitamin B2 tablets, Eudragit L 100-55, Opadry enteric (PVAP) and Aqoat (HPMCAS) proved to be quite stable aqueous enteric coatings, whereas cellulose acetate phthalate CAP or cellulose acetate trimellitate CAT coatings as ammonia-neutralized aqueous solution or as water-based pseudolatex Aquateric were unstable when stored under stress conditions.     

红霉素肠溶微丸制备工艺

采用挤出—滚圆技术制备红霉素微丸丸芯，并用正交设计筛选其制备工艺；以甲基丙烯酸共聚物水分散体为包衣材料，建立微丸包衣数学模型指导包衣工艺。     

柠檬酸三乙酯在奥美拉唑肠溶微丸中的应用

目的研究柠檬酸三乙酯（triethyl citrate,TEC）在奥美拉唑肠溶微丸中的应用。方法分别比较包衣中含TEC和不含TEC对Eudragit L30D-55膜（尤特奇肠溶包衣材料）性质的影响和对奥美拉唑肠溶微丸释药及其表面衣膜质量的影响。结果含10％TEC的Eudragit L30D-55膜较不含TEC的Eudragit L30D-55膜的玻璃化转变温度（Tg）值降低19．75℃。含10％TEC和含5％TEC的肠溶微丸释放度分别为98．7％和82．6％,远远高于不含TEC的微丸。结论TEC能显著改善树脂类包衣材料的Tg,提高膜的柔韧性和完整性,并且能够有效地控制药物释放,可广泛应用于制剂包衣中。     

Combination of a hot-melt subcoating and an enteric coating for moisture protection of hygroscopic Sennae fructus tablets

The objective of this study was to investigate the efficiency of moisture protection of hot-melt coatings solely and in combination with an enteric coating on hygroscopic tablet cores containing a spray-dried Sennae fructus extract. Tablet cores were subcoated with different hot-melt coating materials: medium chain tryglycerides, stearic acid, Precirol^® ATO 5, and Compritol^® 888 ATO, at varying amounts and coated with Eudragit^® L 30D-55 for enteric resistance. Subcoating penetration, tablet disintegration, dissolution times, tablet hygroscopicity, and tablet properties such as weight, height, diameter, and hardness were analyzed. 3?mg/cm² of tablet surface seemed to be sufficient if sustained release is not required. Thereby, hot-melt coating did not adversely affect the tablet properties with regard to subsequent processing steps. Compared to the tablet cores it was possible to reduce the moisture uptake by 85% at 75% relative humidity with tablets coated with a combination of Precirol^® ATO 5 and Eudragit^® L 30D-55. This combination was more efficient than high amounts of Eudragit^® L 30D-55. Hot-melt coating proved to be a suitable technique for the application of subcoating material to tablet cores serving as a barrier against water permeation into hygroscopic tablet cores without exceeding the required disintegration times.