In current decade, pharmaceutical industries of Bangladesh are giving much emphasize on the formulation of time release preparation to treat various chronic diseases in order to decrease the frequency of administratio...In current decade, pharmaceutical industries of Bangladesh are giving much emphasize on the formulation of time release preparation to treat various chronic diseases in order to decrease the frequency of administration and to improve patient compliance. Objectives: The objective of this investigation is to design and evaluate sustained release matrix tablet of Gliclazide by direct compression method employing polymers of hydroxypropylmethyl cellulose (HPMC) derivatives (K15M CR and K4M CR) and to select the optimized formulations and compression process by performing a comparative release kinetic study with a reference product, Diamicron MR (one of the worldwide brand of Gliclazide sustain released tablet manufactured by Servier one of the French pharmaceutical company) tablet. Methods: Release kinetics of Gliclazide matrix tablets were determined using USP paddle method at Phosphate buffer (pH 7.4). The release mechanism was explored and explained with zero order, first order, Higuchi and Korsmeyer model. Result: It is found that formulation with lower polymeric concentration follows Higuchi release kinetics and that the formulation with higher concentration best fits with zero order release kinetics. Among the formulations, F1 and F6 show almost similar dissolution profile with Diamicron MR Tablet, which can be suitable candidates for further in-vivo bioequivalence study. Conclusion: Findings of this investigation suggest that F1 and F6 formulations are potential candidates for further bioequivalence study among other formulations.展开更多
This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries. By using super-and sub-solution techniques, we first give the sufficient conditions that the classical solu...This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries. By using super-and sub-solution techniques, we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively, and then give the necessary and sufficient conditions that two components u and ν blow up simultaneously. Finally, the uniform blow-up profiles in the interior are presented.展开更多
Clear effects criterion is one of the important rules for selecting optimal fractional factorial designs,and it has become an active research issue in recent years.Tang et al.derived upper and lower bounds on the maxi...Clear effects criterion is one of the important rules for selecting optimal fractional factorial designs,and it has become an active research issue in recent years.Tang et al.derived upper and lower bounds on the maximum number of clear two-factor interactions(2fi's) in 2n-(n-k) fractional factorial designs of resolutions III and IV by constructing a 2n-(n-k) design for given k,which are only restricted for the symmetrical case.This paper proposes and studies the clear effects problem for the asymmetrical case.It improves the construction method of Tang et al.for 2n-(n-k) designs with resolution III and derives the upper and lower bounds on the maximum number of clear two-factor interaction components(2fic's) in 4m2n designs with resolutions III and IV.The lower bounds are achieved by constructing specific designs.Comparisons show that the number of clear 2fic's in the resulting design attains its maximum number in many cases,which reveals that the construction methods are satisfactory when they are used to construct 4m2n designs under the clear effects criterion.展开更多
文摘In current decade, pharmaceutical industries of Bangladesh are giving much emphasize on the formulation of time release preparation to treat various chronic diseases in order to decrease the frequency of administration and to improve patient compliance. Objectives: The objective of this investigation is to design and evaluate sustained release matrix tablet of Gliclazide by direct compression method employing polymers of hydroxypropylmethyl cellulose (HPMC) derivatives (K15M CR and K4M CR) and to select the optimized formulations and compression process by performing a comparative release kinetic study with a reference product, Diamicron MR (one of the worldwide brand of Gliclazide sustain released tablet manufactured by Servier one of the French pharmaceutical company) tablet. Methods: Release kinetics of Gliclazide matrix tablets were determined using USP paddle method at Phosphate buffer (pH 7.4). The release mechanism was explored and explained with zero order, first order, Higuchi and Korsmeyer model. Result: It is found that formulation with lower polymeric concentration follows Higuchi release kinetics and that the formulation with higher concentration best fits with zero order release kinetics. Among the formulations, F1 and F6 show almost similar dissolution profile with Diamicron MR Tablet, which can be suitable candidates for further in-vivo bioequivalence study. Conclusion: Findings of this investigation suggest that F1 and F6 formulations are potential candidates for further bioequivalence study among other formulations.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos.10471013,10471022)the Ministry of Education of China Science and Technology Major Projects (Grant No.104090)
文摘This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries. By using super-and sub-solution techniques, we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively, and then give the necessary and sufficient conditions that two components u and ν blow up simultaneously. Finally, the uniform blow-up profiles in the interior are presented.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10571093,10671099and 10771123)the Research Foundation for Doctor Programme (Grant No. 20050055038)+1 种基金the NaturalScience Foundation of Shandong Province of China (Grant No. Q2007A05)Zhang’s research was also supportedby the Visiting Scholar Program at Chern Institute of Mathematics
文摘Clear effects criterion is one of the important rules for selecting optimal fractional factorial designs,and it has become an active research issue in recent years.Tang et al.derived upper and lower bounds on the maximum number of clear two-factor interactions(2fi's) in 2n-(n-k) fractional factorial designs of resolutions III and IV by constructing a 2n-(n-k) design for given k,which are only restricted for the symmetrical case.This paper proposes and studies the clear effects problem for the asymmetrical case.It improves the construction method of Tang et al.for 2n-(n-k) designs with resolution III and derives the upper and lower bounds on the maximum number of clear two-factor interaction components(2fic's) in 4m2n designs with resolutions III and IV.The lower bounds are achieved by constructing specific designs.Comparisons show that the number of clear 2fic's in the resulting design attains its maximum number in many cases,which reveals that the construction methods are satisfactory when they are used to construct 4m2n designs under the clear effects criterion.
