Trimethadione as a Model Drug for the Evaluation of Hepatic Drug-Metabolizing Capacity in Normal and α-Naphthylisothiocyanate-Intoxicated Rats

Pharmacology ◽  
1982 ◽  
Vol 25 (4) ◽  
pp. 202-209 ◽  
Author(s):  
Einosuke Tanaka ◽  
Haruki Kinoshita ◽  
Takemi Yoshida ◽  
Yukio Kuroiwa
Keyword(s):  
1982 ◽  
Vol 32 (6) ◽  
pp. 1182-1185 ◽  
Author(s):  
Einosuke TANAKA ◽  
Haruki KINOSHITA ◽  
Takemi YOSHIDA ◽  
Yukio KUROIWA
Keyword(s):  

1982 ◽  
Vol 32 (6) ◽  
pp. 1182-1185
Author(s):  
Einosuke TANAKA ◽  
Haruki KINOSHITA ◽  
Takemi YOSHIDA ◽  
Yukio KUROIWA
Keyword(s):  

1988 ◽  
Vol 6 (3) ◽  
pp. 374-382 ◽  
Author(s):  
Henrik E. Poulsen ◽  
Steffen Loft
Keyword(s):  

Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


Author(s):  
Surender Verma ◽  
S. Singh ◽  
D. Mishra ◽  
Atul Gupta ◽  
Rakesh Sharma

The objective of present study was to develop colon targeted drug delivery using bacterially triggered approach through oral route. Valdecoxib (COX-2 inhibitor) was chosen as a model drug in order to target it to colon which may prove useful in inflammatory bowel disease and related disorders. Matrix tablets of Valdecoxib were prepared by wet granulation technique utilizing different ratio of Guar gum and Sodium starch glycholate. The prepared matrix tablets were evaluated for uniformity of weight, uniformity of content, hardness and in vitro dissolution study in simulated gastric and intestinal fluid (Phosphate Buffer pH-1.2, pH-6.8 and pH-7.4), followed by Dissolution study in bio-relevant dissolution media Phosphate Buffer (pH-6.8) containing rat caecal content. The results revealed that the formulated batch had released lesser quantity of drug at pH 1.2 and pH 7.4 in 2 hors whereas in biorelevent dissolution media containing rat caecal content it released significantly higher amount of drug which was also significantly higher than the dissolution media of same pH without caecal content (microflora) and it was concluded that guar gum can be used as a potential carrier for targeting drugs to colon.


Author(s):  
V A. Vamshi Priya ◽  
G. Chandra Sekhara Rao ◽  
D. Srinivas Reddy ◽  
V. Prabhakar Reddy

The purpose of this study was to investigate the efficiency of superdisintegrants: sodium starch glycolate, croscarmellose sodium and crospovidone in promoting tablet disintegration and drug dissolution of Topiramate immediate release tablets. The efficiency of superdisintegrants was tested, by considering four concentrations, viz., like 2%, 3%, 4% and 5% in the formulations. The dissolution was carried out in USP apparatus II at 50 rpm with distilled water as a dissolution medium. The dissolution rate of the model drug topiramate was found highly dependent on the tablet disintegration, on the particle size of the superdisintegrant, on the solubility of the drug and also on the type of superdisintegrant in the dissolution medium. There was no effect of the diluent (Lactose monohydrate) on the disintegration of different concentrations of superdisintegrants. These results suggest that, as determined by the f2 metric (similarity factor), the dissolution profile of the formulation containing 4% sodium starch glycolate and lactose monohydrate as a diluent was similar to that of a marketed product.


Author(s):  
Y. Madhusudan Rao ◽  
Katakam V V ◽  
S Reddy ◽  
J M Somagoni ◽  
P K Panakanti ◽  
...  

The aim of this study was to prepare mini tablets to be filled into a capsule that is designed to float on the gastric contents based on gas formation technique. The drug-containing core mini-tablets were prepared by wet granulation method followed by a coating of the core units with seal coating, an effervescent layer and a gas-entrapping polymeric membrane (Eudragit RS30D, RL30D). Dipyridamole, which is predominantly absorbed in the upper part of GI tract and unabsorbed/insoluble at the lower intestine, was used as a model drug. The effect of the preparative parameters like amount of the effervescent agent layered onto the seal coated units, type and coating level of the gas-entrapping polymeric membrane, floating ability and drug release properties of the multiple-unit FDDS were evaluated. The formulations were evaluated for pharmacopoeial quality control tests. Physical parameters were found to be within the acceptable limits. The system using Eudragit® RL30D as a gas-entrapping polymeric membrane exhibited floating properties. The time to float decreased as amount of the effervescent agent increased and coating level of gas-entrapping polymeric membrane decreased. The optimum system exhibited complete floating within 3 minutes and maintained that buoyancy over a period of 8 hours. The drug release was sustained and linear with the square root of time. Increasing the coating level of the gas-entrapping polymeric membrane decreased drug release. Both the rapid-floating and sustained-release properties were achieved in the multiple-unit floating delivery system developed in this study. The in vivo gastric residence time was examined by radiograms and it was found that the units remained in the stomach for about 6 hours. The analysis of the dissolution data after storage at 40°C and 75% RH for 6 months showed no significant change indicating good stability.


2019 ◽  
Vol 25 (35) ◽  
pp. 3740-3750 ◽  
Author(s):  
Ning Sun ◽  
Dongli Li ◽  
Xiaoqing Chen ◽  
Panpan Wu ◽  
Yu-Jing Lu ◽  
...  

Oleanolic acid is an analogue of pentacyclic triterpenoids. It has been used as a hepatic drug for over 20 years in China. Currently, there are only five approved drugs derived from pentacyclic triterpenoids, including oleanolic acid (liver diseases), asiaticoside (wound healing), glycyrrhizinate (liver diseases), isoglycyrrhizinate (liver disease) and sodium aescinate (hydrocephalus). To understand more about the bioactivity and functional mechanisms of oleanolic acid, it can be developed as a potent therapeutic agent, in particular, for the prevention and treatment of heart diseases that are the leading cause of death for people worldwide. The primary aim of this mini-review is to summarize the new applications of oleanolic acid and its derivatives as cardioprotective agents reported in recent years and to highlight their therapeutic perspectives in cardiovascular diseases.


2020 ◽  
Vol 16 (9) ◽  
pp. 1404-1410
Author(s):  
Rishabha Malviya

Background: In the previous study, investigators have synthesized acrylamide grafted and carboxymethylated derivatives of neem gum and evaluated their potential in the formulation of nanoparticles. In continuation of previous work, authors have evaluated neem gum polysaccharide (NGP), acrylamide grafted neem gum polysaccharide (NGP-g-Am) and carboxymethylated neem gum polysaccharide (CMNGP) as binding agent in the tablet dosage form. Methods: Diclofenac sodium was used as a model drug while microcrystalline cellulose and talc were used as excipient in the preparation of granules employing wet granulation technique. NGP, NGP-g-Am and CMNGP were utilized as binding agent in the preparation of granules. Prepared granules were characterized for various pre-compression and post-compression parameters. Results and Discussion: Binding agents were used in the concentration of 4-24%w/w. NGP incorporated granules showed more bulk density and lower values of tapped density, Carr’s index, bulkiness, Hausner’s ratio and angle of repose as compared to NGP-g-Am consisting granules. NGP-g-Am consisting tablets showed more hardness and zero friability as compared to NGP based tablets. Drug content was found lower for the tablets having grafted polymer in place of NGP. CMNGP were also utilized to prepare granules but granules were not be able to compress keeping all the compacting parameters same as used in the case of NGP and NGP-g-Am consisting granules. NGP and NGP-g-Am were able to sustain drug release up to 6 and 8 h, respectively. Conclusion: It can be concluded that NGP-g-Am induces better properties when used as a binder in the tablet formulation than native polymer, while CMNGP cannot be utilized as a binding agent in the preparation of a tablet.


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