ABSTRACT
OBJECTIVE： To design and optimize the formulation and technology of Theophylline hydrophilic gel matrix sustained-release tablets （self-made sustained-release tablets for short） based on the concept of “Quality by Design” （QbD）. METHODS： Diluent type， tablet diameter， the property of adhesive （ratio of different adhesive types）， the amount of adhesive were regarded as critical process parameters （CPPs）. Similarity factor of dissolution curves of self-made Theophylline sustained-release tablets and reference preparation and its accumulative release rate at different time points were regarded as critical quality attributes （CQAs）. L18（34） orthogonal tablet was adopted for design and trial， and secondary polynomial regression model was established. By using Modde 12.0 software， the design space and its acceptable range （PAR） were calculated through the optimal model. The optimal formulation and technology of Theophylline sustained-release tablets was determined， and validation test and Monte Carlo simulation verification were conducted. RESULTS： The optimal model with good coincidence， accuracy， validity and reproducibility was obtained， which could better fit the relationship between CQAs and CPPs. The design space and PAR value were obtained by further calculation （The optimum value of diluent was lactose； tablet diameter was 9.07-9.33 mm， and the optimal value was 9.20 mm； ratio of HPMC K4M to HPMC was 0.50-0.83， and the optimal value was 0.80； total amount of HPMC was 0.036 0-0.041 3 g per tablet， and the optimal value was 0.038 g per tablet）. The optimal formulation and technology included that ratio of theophylline， HPMC K4M and HPMC K100M were 50％， 15.48％ and 3.87％， respectively； the rest was filled with lactose and the diameter of the tablet was 9.20 mm. The results of validation confirmed that self-made Theophylline sustained-release tablets had similar in vitro release behavior compared with reference preparation. CONCLUSIONS： Based on the concept of QbD， the formulation and technology of Theophylline sustained-release tablets can meet the requirements of design， and the CPPs can be adjusted within the PAR range to meet the requirements of CQAs. This shows that the QbD concept is scientific and effective in the design and optimization of the formulation and technology of sustained and controlled release preparations.
ABSTRACT
Objective To prepare brucine solid lipid nanoparticles (SLN) and its lyophilized powder, and then hydrogel matrix sustained-release tablets (HMST) of brucine SLN (SLN-HMST) were prepared. The factors that may influence drug release in vitro and release mechanism were also investigated in present study. Methods Based on single factor test, orthogonal test was designed to gain the optimum prescription. Zero-order, First-order and Higuchi models were used for the model fitting of drug release. Ritger-Pappas models were employed to study release mechanism of brucine SLN-HMST. Results Brucine SLN-HMST was better agreed with First-order kinetics model. The equation was ln(1-Mt/M∞) = -0.212 1 t + 0.106 4 (r = 0.992 3). The cumulative release could achieve 91.48% in 12 h. The sustained release features were obviously. The drug release from the tablets was controlled by diffusion and degradation of the matrix. Conclusion The prepared brucine SLN-HMST can deliver drug continually for 12 h with good reproducibility.
ABSTRACT
Objective: To prepare hydrogel matrix sustained-release tablets of resveratrol solid lipid nanoparticles, and the factors that might influence drug release and in vitro release models were also investigated in present study. Methods: The resveratrol-solid lipid nanoparticles (Res-SLN) were prepared by thin-film ultrasonic dispersion method, and then the hydrogel matrix was prepared by dispersed in excipients of hydrogel matrix sustained-release tablets. Single factor analysis was used to study the effects of varieties of adhesives, PEG, HPMC, and the amounts of HPMC K15 on drug release. Then the orthogonal design was used to gain the optimum formulation. Zero-order, first-order, Higuchi, and Ritger-Pappas models were used for the model fitting of drug release. Results: Hydrogel matrix sustained-release tablet of Res-SLN was better accorded with Zero-order kinetics model. The equation was Mt/M∞ = 0.078 7 t + 0.003 6 (r = 0.998 0). In vitro release behavior was in line with Ritger-Peppas equation, and the drug release from the tablets was controlled by degradation of the matrix. Conclusion: Prescription of hydrogel matrix sustained-release tablet of Res-SLN is reasonable; The preparation technology is feasible and exhibits perfect sustained-release characteristics in vitro in 12 h.
ABSTRACT
OBJECTIVE:To prepare Venlafaxine hydrochloride sustained-release tablets,and to investigate the characteristics of drug release. METHODS:Using glyceryl behenate as lipidic matrix material and HPMC as hydrophilic matrix material,the kind and dosage of excipients were screened by single factor experiment. Using 4,8,24 h accumulative release rate and the deviation summation of ideal values as index,the viscosity of HPMC,the amounts of HPMC K15M and glyceryl behenate were optimized by orthogonal test. The dissolution curves were fitted by different equations. RESULTS:The optimal formulation was as follows as venlafaxine hydrochloride 8.5 kg,HPMC K15M 15 kg,glyceryl behenate 26 kg,magnesium stearate 0.5 kg. 4,8,24 h accumula-tive release rates of prepared matrix sustained-release tablets were 34.3%,63.9% and 99.2%,respectively. The releases profiles of hydrophilic and lipidic matrix sustained release tablets followed first-order equation in vitro mainly through matrix erosion. CON-CLUSIONS:Venlafaxine hydrochloride hydrophilic and lipidic matrix sustained-release tablets with good sustained-release effect have been prepared successfully.