Application of quality by design in granulation process for ginkgo leaf tablet (Ⅳ)： influence and control of raw materials' quality variation / 中国中药杂志

Raw materials' quality variation could affect the quality consistency of product and the clinical efficacy. In this paper, the high shear wet granulation (HSWG) process of the ginkgo leaf tablet was taken as the research object. Ginkgo biloba extracts and excipients microcrystalline cellulose collected from various sources and batches were used to simulate raw materials' quality variation. Real-time torque was recorded to analyze the viscosity of the wetting mass, and then by combining with physical fingerprint, the impact of physical quality variation of powders on granule properties could be investigated. Based on regime map thesis, whether the granules' nucleation mode was in mechanical dispersion regime was determined by calculating dimensionless parameters, which would lead to the unstable output in considerations of granule yield ratio and particle size distribution (PSD) curve. The orthogonal partial least square (OPLS) model was adopted to build the relationship between the micromeritic properties and the mediangranule size (D50) of Ginkgo biloba granules and then the critical material attributes (CMAs) were screened by variable importance in the projection (VIP) indexes. The results demonstrated that the properties of powders including hygroscopicity, angle of repose, Hausner ratio, Carr index, D10 and loss on drying affected the granule size. Besides, Ginkgo biloba granules were compressed into tablets. In view of tensile strength analysis, the raw materials' quality variation did not result in decrease of tensile strength of the ginkgo leaf tablets. The design space of critical quality attributes (CQAs) and the process design space which could cope with raw materials' quality variation were proved to be robust..

Analysis of Torque Curve in Isokinetic Knee Dynamometer

OBJECTIVE: To analyze the patterns of isokinetic knee torque curves in normal population and determine the characteristics of those curves. METHOD: Two hundred and eightly-six normal subjects were included. The isokinetic knee torque curves were divided into three parts; to the angle of peak torque generation, to the point 10~20 degrees prior to end of joint motion, and to the end of joint motion. Each part was classified as convex(1), flat(2) and concave(3) type according to the shape. The curves were named such as 1-2-2 in order. Types of the curves, peak torque, angle of knee at peak torque, total acceleration energy, age, and sex of the subjects were compared. RESULTS: For knee extensors, frequencies of the curve types were 1-2-2(A), 1-2-1(B), 1-3-1(C), and 1-3-2(D). Mean ages of type A and B curves were slightly higher than types of C and D. Mean peak torque was greatest in type D. For knee flexors, the frequencies were 1-2-2(A), 1-2-1(B), and 1-1-2(C). Female predominance were found in type B while type C was found mostly in male. Mean peak torque was greatest in type C. CONCLUSION: The most common torque curve type was 1-2-2 for knee extensors and flexors. Torque curve types of knee extensors showed differences in age and torque curve types of knee flexors showed differences in sexual distribution.

Torque Curves and Heart Rate Responses to Isometric, Eccentric and Concentric Isokinetic Exercises of the Knee and Elbow Joints

OBJECTIVE: To investigate the torque curves and heart rate responses to isometric, eccentric and concentric isokinetic exercises with a maximal voluntary contraction of the right knee and elbow joints in 30 healthy men(26.6+/-2.2 years). METHOD: Subjected performed the eccentric and concentric isokinetic exercises with 10 repetitions at 60o/sec, while performing the isometric exercises at a joint angle of 60 degrees for the same period of time with Cybex 6000. Peak torque, angle of peak torque, and total work were measured and the flexor-to-extensor ratios of peak torque were calculated. Heart rates were recorded simultaneously at rest and immediately after the exercise, and the time required to return to the resting heart rate level was also recorded for each exercise session. RESULTS: Peak torque and total work for the eccentric exercise were significantly higher than those for the concentric exercise(p<0.01) of the knee and elbow joints. Eccentric peak torques for flexors and extensors of the knee joint occurred at a significantly longer muscle length than the concentric peak torques(p<0.01). Flexor-to-extensor ratios of a peak torque of the knee joint between the eccentric and concentric isokinetic exercises did not show a significant difference. Torques at a joint angle of 60 degrees were highest in the eccentric isokinetic exercise, followed in the order by isometric, and then concentric isokinetic exercises of the knee joint(p<0.01), and concentric torque at a joint angle of 60 degrees was significantly lower than those of the eccentric and isometric exercises of the elbow joint. The increase in heart rate and the time of returning to the resting heart rate level were independent of the size of the contracting muscle mass and the types of exercise. The increment ratio for the heart rate was 70.4+/-23.6%. CONCLUSION: In conclusion, the response of heart rate to the exercise is not influenced by the contracting muscle mass or the types of exercise in a short duration of maximal voluntary contraction, implying that special precautionary measures are not required for the isometric, eccentric and concentric isokinetic exercises.