The non-uniformity of microcrystalline cellulose bilayer tablets

The material response of the constrained microcrystalline cellulose particles during the manufacture of bilayer tablets has been investigated. This work exploits the ability of a non-contact optical profilometer to elucidate both the intricate roughness detail and the inherent form of a compacted sample surface within one measurement. Thus the effects of the imposed non-uniform stress pattern that develops during the two sequential compaction cycles have been determined. The indirect measurement procedure has been able to infer the degree of particle deformation and hence the relative local porosity can be determined. The application of two compaction cycles has shown to exasperate the inhomogeneity of the localised regions of stored elastic strain energy and this is highlighted by the non-uniform and complex ejected tablet geometry. The localised stored energy release by volume expansion in the radial direction is thought to be responsible for the fracture of tablets during the ejection phase of the manufacturing process. When the magnitude of the final layer compaction stress is greater than the initial layer compaction stress the radial volume expansion can even result in the rupture of junctions between particles in the adjacent layers at the periphery of the interfacial zone. Thus the energy dissipation by volume expansion is a possible explanation for the stress concentrating crack commonly present at interfacial boundary zone within the bilayer formulations.     

Evaluation of performance of co crystals of mefloquine hydrochloride in tablet dosage form

Objective: The objective of present investigation was to evaluate performance of cocrystals of Mefloquine Hydrochloride (MFL) in tablet dosage form. Our previous investigation showed significant effect of cocrystal formers on improving the solubility and dissolution rate of Mefloquine hydrochloride by cocrystallization method when prepared by solution cocrystallization method.

Materials and methods: Prepared cocrystals of MFL with different ratio of cocrystal formers were incorporated in tablet dosage form and evaluated for micrometric properties, drug content, hardness, disintegration test, vitro dissolution studies and stability studies. Performance was compared with laboratory prepared tablet of MFL 250 mg.

Results: The considerable improvement in the dissolution rate was observed in case of cocrystals based tablets than pure MFL tablets.

Discussion and conclusion: So we can incorporate cocrystals in tablet dosage form to enhance in vitro and in vivo performance. To the best of our knowledge, this is the first report, cocrystals has been evaluated in tablet dosage form.     

Determination of carbamazepine polymorphic contents in double-layered tablets using transmittance- and reflectance-near-infrared spectroscopy involving chemometrics

Background: Since polymorphs exhibit differences in chemical and physicochemical stability, characteristics, and dissolution rate of the bulk powder, they may significantly affect on the bioavailability of pharmaceutical compounds. Aim: The purpose of the present study is to establish a method for determining the carbamazepine (CBZ) polymorphic content of a double-layered tablet containing various ratios of forms I and III by using transmittance- and reflectance-near-infrared (TNIR and RNIR) spectroscopy involving chemometrics. Methods: Both TNIR and RNIR instruments were used to analyze both top (form I) and wire (form III) sides of the compacts, respectively. NIR spectra were analyzed to predict polymorphic content by a principal component regression analysis. NIR data of the tablets were divided into two wavelength ranges: between 860 and 1680 nm (FW), and 1245 and 1285 nm (NW). Results: The calibration models for polymorphic content based on TNIR had a linear relationship, but those based on RNIR did not. The accuracy of the calibration models suggested that the double-sided data set is more robust than the single-sided data set. Since the spectra of FW involved various information, the calibration models showed a linear correlation, but it is difficult to understand their model. In contrast, those of NW provided limited information on polymorphic forms making it very easy to understand the model. Conclusion: Limiting the wavelength of the spectra is useful to help understand the calibration-complicated model.     

盐酸奈福泮缓释片药代动力学及生物等效性

目的: 验证盐酸奈福泮缓释片的缓释特性并判定其生物等效性。方法: 18 名健康受试者随机分成两组, 采用双周期交叉试验设计, 单剂量、 多剂量连续给药, 用高效液相色谱法测定血药浓度, 以3p97 药代动力学程序求算相关参数。 结果: 单剂量给药的结果表明 :缓释片在给药后 2 ~ 12 h 内血药浓度维持在 20 ~ 40 mg·L^-1 之间, c_max 为(45.8 ±15.7) mg·L^-1, t_peak 为(3.4 ±0.8) h; 普通片在给药后 0.5 ~ 8 h 内血药浓度维持在 20 mg·L^-1 以上,c max 为(72.7 ±26.0) mg·L^-1, t_peak 为(1.6 ±0.6) h。两制剂的 AUC 分别为(363.4 ±107.7) 及(374. 8 ±125.7) mg·h·L^-1, 平均相对生物利用度为1.02 ±0.25。多剂量给药的结果表明:缓释片和普通片的c_max 分别为(31.5 ±12.7) 及(33.7 ±10.5) mg·L^-1, c_min 分别为(13.4±4.4) 及(10.9 ±5.4) mg·L^-1, t_peak分别为 (2.6 ±0.6) 及 (1.2 ±0.5) h, FI 分别为0.77±0.26 及 1.04±0.18。结论: 该缓释片具有缓释特征, 两制剂生物利用度 (AUC) 具有等效性。     

苯那普利的联合用药选择:左旋氨氯地平与硝本地平缓释片的对比分析

目的:比较苯那普利与苯磺酸左旋氨氯地平和硝本地平缓释片合用, 治疗单用苯那普利不能控制其血压降至目标水平的原发性高血压患者的疗效、副反应。方法:112 例单用苯那普利治疗不能控制至理想血压的患者, 在原有剂量不变下, 加用苯磺酸左旋氨氯地平或硝本地平缓释片治疗, 用药后4周判断降压效果, 不良反应。结果:加用苯磺酸左旋氨氯地平后有效率为85.71 %, 加用硝本地平缓释片为78.57 %, 两组无显著的统计学意义(P >0.05), 加用苯磺酸左旋胺氯地平后的显效率有(73.21 %) 高于加用硝本地平缓释片(54.38 %, P <0.05);不良反应显著低于加用硝本地平组(7.14 %vs 28.5 %, P <0.01) 。结论:对单用苯那普利治疗不能控制其理想血压的患者, 苯那普利合用苯磺酸左旋胺氯地平或苯那普利合用硝本地平缓释片治疗都是有效的。苯那普利和苯磺酸左旋胺氯地平联合更适合于此类病人的抗高血压治疗。     

TLC-UV法测定复方黄连素片中盐酸小檗碱

采用TLC法将复方黄连素片中的盐酸小檗碱与其它成分分离,定位后,用紫外可见分光光度计测定其含量。TCL-UV法精密度RSD%为1.45%;回收率为98.28%,RSD%为1.73%（n=6）。结果表明,该法高效、灵敏、重现性好,可用作复方黄连素片的质量控制方法。     

Film-Coated Enteric Tablet Formulation of Ketorolac Tromethamine

Abstract

A great majority of polymers used for pharmaceutical film-coating purposes have been derivatives of cellulose or methacrylate copolymers (Eudragit series) in most recent studies. The type and frequency of the ester substituents in the chemical structure of these polymers determines their water permeability and pH-solubility characteristics; therefore, different members of the series may be employed for taste-masking or as enteric-coating agents or dissolution rate-controlling membranes in sustained-release dosage forms. Ketorolac tromethamine (KT) is a non-steroidal drug with potent analgesic and anti-inflammatory activity and is absorbed rapidly (T_max < 1.0 hr) with an efficiency of > 87% following oral and intramuscular administration. The most frequent adverse effects occurring with KT are gastrointestinal disturbances such as peptic ulceration and gastrointestinal bleeding. For this reason, enteric-coated film tablets of KT were prepared in this study by the spray technique. Eudragit S-100 and L-100 were selected as coating materials. Polyethylene glycol (PEG) 4000 was used as a plastifying agent. Core tablets of KT were prepared by the direct compression technique. Tablet specifications were determined and evaluated statistically.     

加氢催化剂压片成型及强度影响因素研究

催化反应中,压片成型催化剂需要兼顾催化性能和机械强度。通过研究压片用模具尺度、压片机压强、压力保持时间、催化剂粘结剂用量、催化剂粒径对加氢催化剂成型和强度的影响,确定加氢催化剂压片成型优化条件:直径5mm圆柱形磨具、压力10 MPa、压力保持时间2 s、添加粘结剂的质量分数2.5%、粉末粒径(80～150)目。在确定优化压片条件下,可以得到径向抗压碎力40 N·mm~(-1)的催化剂样品。催化剂在模式装置上评价的结果比较理想,转化率超过99%,选择性超过99%,且催化剂在1 000 h后仍然可以保持较好的性能。     

Estimation of bottle filling counts for conventional pharmaceutical tablets and capsules

A method has been developed using commonly available data for estimating the number of tablets or hard shell capsules that can be filled into bottles. The single unit volumes of conventional pharmaceutical biconvex tablets and capsules can be calculated from simple geometric relationships, which then can be used to determine the packing fraction of the units in bottles. The packing fractions of capsules and tablets studied in this work ranged from 0.53 to 0.63 and 0.56 to 0.62, respectively, and were dependent on bottle size and shape. This method can be used to assess a variety of packaging configurations computationally during drug product development.