In vivo Drug Release Rate from Hard Gelatin Capsules

1965 ◽  
Vol 54 (8) ◽  
pp. 1207-1208 ◽  
Author(s):  
John H. Wood
Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 260 ◽  
Author(s):  
Dongwei Wan ◽  
Min Zhao ◽  
Jingjing Zhang ◽  
Libiao Luan

This study aimed to develop a novel sustained release pellet of loxoprofen sodium (LXP) by coating a dissolution-rate controlling sub-layer containing hydroxypropyl methyl cellulose (HPMC) and citric acid, and a second diffusion-rate controlling layer containing aqueous dispersion of ethyl cellulose (ADEC) on the surface of a LXP conventional pellet, and to compare its performance in vivo with an immediate release tablet (Loxinon®). A three-level, three-factor Box-Behnken design and the response surface model (RSM) were used to investigate and optimize the effects of the citric acid content in the sub-layer, the sub-layer coating level, and the outer ADEC coating level on the in vitro release profiles of LXP sustained release pellets. The pharmacokinetic studies of the optimal sustained release pellets were performed in fasted beagle dogs using an immediate release tablet as a reference. The results illustrated that both the citric acid (CA) and ADEC as the dissolution- and diffusion-rate controlling materials significantly decreased the drug release rate. The optimal formulation showed a pH-independent drug release in media at pH above 4.5 and a slightly slow release in acid medium. The pharmacokinetic studies revealed that a more stable and prolonged plasma drug concentration profile of the optimal pellets was achieved, with a relative bioavaibility of 87.16% compared with the conventional tablets. This article provided a novel concept of two-step control of the release rate of LXP, which showed a sustained release both in vitro and in vivo.


1980 ◽  
Vol 4 (3) ◽  
pp. 175-183 ◽  
Author(s):  
E. Hunter ◽  
J.T. Fell ◽  
R.T. Calvert ◽  
H. Sharma

RSC Advances ◽  
2015 ◽  
Vol 5 (32) ◽  
pp. 25164-25170 ◽  
Author(s):  
Bo Zhang ◽  
Teng Zhang ◽  
Quanxi Wang ◽  
Tianrui Ren

A controlled release system was prepared, it based on UF modified PCC cells in which TEB are loaded into cells. It can control the drug release rate, depress the initial “burst effect”, and was efficacious in controlling wheat powdery mildew.


Biomaterials ◽  
2001 ◽  
Vol 22 (21) ◽  
pp. 2857-2865 ◽  
Author(s):  
Giacomo Fontana ◽  
Mariano Licciardi ◽  
Silvana Mansueto ◽  
Domenico Schillaci ◽  
Gaetano Giammona

2015 ◽  
Vol 15 (01) ◽  
pp. 1550012
Author(s):  
YANG ZHANG ◽  
RENJIE WU ◽  
YING HU ◽  
YU DONG ◽  
LIFENG SHEN ◽  
...  

Background: Antibiotic-impregnated calcium sulfate delivery systems (ACDS) are commonly used to treat chronic osteomyelitis. Our research is to investigate drug release in vitro over a longer period, as a cautious predictor of in vivo release. Methods: The local release behavior of antibiotic in vitro was simulated. The consecutive dynamic eluting experiment was performed based on the pro-operative characteristic of osteomyelitis patients and the determined results of drug concentration in the human drainage tissue fluid (DTF). The concentration of each drug in the receiving solution was detected by ultra-performance liquid chromatography-tandem quadrupole detector mass spectrometry. The ACDS was reviewed by scanning electronic microscopy (SEM) after 48 h, and prepared to be eluted for another examination after 33 days. The mechanism of antibiotic release was analyzed by using the Ritger–Peppas and Weibull equations. Results: The cumulative release rate of vancomycin in a vancomycin-calcium sulfate delivery system (VCDS) was 77.50 % (3.0 mm diameter) and 72.43 % (4.8 mm diameter), while that of the tobramycin in a tobramycin-calcium sulfate delivery system (TCDS) was 88.0 % (3.0 mm diameter) and 84.55 % (4.8 mm diameter). At the 15th day, approximately 27.92% of vancomycin was and 29.35% of tobramycin was released from the local implant in vivo. Using SEM, numerous vancomycin and tobramycin particles were found to be attached to the columnar calcium sulfate crystals at the start of the experiment. The release behavior of the two antibiotics followed a combination of Fickian diffusion and Case II transport mechanisms within the first 48 h, and a Fickian diffusion mechanism during the subsequent time period. The correlation coefficient of tobramycin and vancomycin in vivo and in vitro was 0.9704–0.9949 and 0.9549–0.9782, respectively. Conclusion: A good correlation of the in vivo and in vitro cumulative release rates was observed by comparing the cumulative release rate of drugs in vitro by means of the dynamic eluting model, and in the DTF. Therefore, our study has proved that it is possible to use the dynamic eluting model as a cautious predictor of in vivo release.


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