In Vitro and In Vivo Evaluation of Guar Gum-Based Matrix Tablets of Rofecoxib for Colonic Drug Delivery

2005 ◽  
Vol 2 (2) ◽  
pp. 155-163 ◽  
Author(s):  
S. Al-Saidan ◽  
Y. Krishnaiah ◽  
V. Satyanarayana ◽  
G. Rao
2005 ◽  
Vol 6 (1) ◽  
pp. E14-E21 ◽  
Author(s):  
Saleh M. Al-Saidan ◽  
Yellela S. R. Krishnaiah ◽  
S. Patro ◽  
Vemulapalli Satyanaryana

2017 ◽  
Vol 8 (4) ◽  
Author(s):  
M Balakrishnaiah ◽  
V. Rama Mohan Gupta

<p>An attempt has been made to develop and optimize an novel anti hypertensive trilayered controlled release matrix tablets incorporated with Olmesartan medoxomil solid dispersion prepared by direct compression and consisted of middle active layer with different grades of hydroxypropylmethylcellulose (HPMC), guar gum, ethyl cellulose. Upper and lower layers are prepared with Carnauba wax, guar gum and sodium CMC. The developed drug delivery system provided prolonged drug release rates over a period of 24 h. The release profile of the optimized formulation (HF14) was described by the Zero-order and Higuchi model. In-vivo bioavailability studies were carried out with the optimized formulation (HF14) and reference standard A fair correlation between the dissolution profile and bioavailability for the optimized formulation was observed. The results indicate that the approach used could lead to a successful development of a trilayer extended release formulation up to 24h. These results also demonstrated that the Olmesartan solid dispersion incorporated trilayer tablets shown more bioavailability because of its conversion from crystalline to amorphous form.</p>


Author(s):  
Rama Rao Tadikonda ◽  
Satyanarayana Sreemantula

The present investigation was carried out to evaluate the utility of guar gum as a hydrophilic matrix carrier in the design of oral controlled drug delivery. Based on the earlier reports, the low viscosity guar gum appears to be superior to medium and high viscosity grades of guar gum in providing a sustained delivery of theophylline along the GI tract. Conducting in vivo studies on theophylline matrix tablets containing 10% of low viscosity guar gum as a representative formulation assessed the in vivo performance of the guar gum matrix tablets. The in vivo studies were carried out in dogs. The effective concentration of theophylline was sustained for a period of 16 hours. The extended tmax, reduced absorption rate constant, prolonged MRT, unchanged Cmax and unchanged bioavailability indicate a controlled release of theophylline from the guar gum matrix tablets resulting in a sustained absorption and prolonged blood levels of theophylline. The theophylline matrix tablets showed blood levels well below 15 ?g/mL indicating freedom from adverse effects. Based on the studies, guar gum appears to be a potential carrier in the design of oral controlled drug delivery systems.


2004 ◽  
Vol 20 (3) ◽  
pp. 347-353 ◽  
Author(s):  
C. Bott ◽  
M. W. Rudolph ◽  
A. R. J. Schneider ◽  
S. Schirrmacher ◽  
B. Skalsky ◽  
...  

Author(s):  
Mohini Sihare ◽  
Rajendra Chouksey

Aim: Nateglinide is a quick acting anti-diabetic medication whose potent activity lasts for a short duration. One of the dangerous side effects of nateglinide administration is rapid hypoglycemia, a condition that needs to be monitored carefully to prevent unnecessary fatalities. The aim of the study was to develop a longer lasting and slower releasing formulation of nateglinide that could be administered just once daily. Methods: Matrix tablets of nateglinide were prepared in combination with the polymers hydroxypropylmethylcellulose (HPMC), eudragits, ethyl cellulose and polyethylene oxide and the formulated drug release patterns were evaluated using in vitro and in vivo studies. Conclusion: Of the seventeen formulated matrix tablets tested, only one formulation labelled HA-2 that contained 15% HPMC K4M demonstrated release profile we had aimed for. Further, swelling studies and scanning electron microscopic analysis confirmed the drug release mechanism of HA-2. The optimized formulation HA-2 was found to be stable at accelerated storage conditions for 3 months with respect to drug content and physical appearance. Mathematical analysis of the release kinetics of HA-2 indicated a coupling of diffusion and erosion mechanisms. In-vitro release studies and pharmacokinetic in vivo studies of HA-2 in rabbits confirmed the sustained drug release profile we had aimed for. Keywords: Hydroxypropylmethylcellulose, Matrix tablets, Nateglinide, Sustained release


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