[20] Imipramine: A model drug for P450 research

1996 ◽  
pp. 177-186 ◽  
Author(s):  
Kim Brøsen ◽  
Erik Skjelbo ◽  
Karin Kramer Nielsen
Keyword(s):  
Model Drug

Controlled Release of Metformin Hydrochloride I. In vitro Release from Physical Mixture Containing Xanthan Gum as Hydrophilic Rate Retarding Polymer

1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza
Keyword(s):  
Controlled Release ◽  
Xanthan Gum ◽  
In Vitro Release ◽  
Correlation Coefficients ◽  
High Ratio ◽  
Water Soluble ◽  
Metformin Hydrochloride ◽  
Model Drug ◽  
Very High

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

Formulation and Evaluation of Microbially- triggered tablets of Valdecoxib

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Surender Verma ◽  
S. Singh ◽  
D. Mishra ◽  
Atul Gupta ◽  
Rakesh Sharma
Keyword(s):  
Phosphate Buffer ◽  
Guar Gum ◽  
Oral Route ◽  
Matrix Tablets ◽  
In Vitro Dissolution ◽  
Wet Granulation ◽  
Dissolution Study ◽  
Caecal Content ◽  
Model Drug

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.

The Effect of Different Superdisintegrants and their Concentrations on the Dissolution of Topiramate Immediate Release Tablets

2009 ◽  
Vol 2 (2) ◽  
pp. 531-5366
Author(s):  
V A. Vamshi Priya ◽  
G. Chandra Sekhara Rao ◽  
D. Srinivas Reddy ◽  
V. Prabhakar Reddy
Keyword(s):  
Immediate Release ◽  
Drug Dissolution ◽  
Dissolution Profile ◽  
Dissolution Medium ◽  
Lactose Monohydrate ◽  
Sodium Starch Glycolate ◽  
Tablet Disintegration ◽  
Croscarmellose Sodium ◽  
Model Drug ◽  
Usp Apparatus

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.

Preparation and Evaluation of a Gas Formation-based Multiple-Unit Gastro-Retentive Floating Delivery System of Dipyridamole

2012 ◽  
Vol 5 (1) ◽  
pp. 1607-1616
Author(s):  
Y. Madhusudan Rao ◽  
Katakam V V ◽  
S Reddy ◽  
J M Somagoni ◽  
P K Panakanti ◽  
...  
Keyword(s):  
Drug Release ◽  
Delivery System ◽  
Polymeric Membrane ◽  
Wet Granulation ◽  
Physical Parameters ◽  
Gastric Residence Time ◽  
Gas Formation ◽  
Multiple Unit ◽  
Model Drug

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.

Exploration of Neem Gum, Acrylamide Grafted Neem Gum and Carboxymethylated Neem Gum as Retardant in Tablet Formulation

2020 ◽  
Vol 16 (9) ◽  
pp. 1404-1410
Author(s):  
Rishabha Malviya
Keyword(s):  
Diclofenac Sodium ◽  
Tablet Formulation ◽  
Angle Of Repose ◽  
Wet Granulation ◽  
Binding Agent ◽  
Grafted Polymer ◽  
Model Drug ◽  
Tablet Dosage ◽  
Tapped Density ◽  
Derivatives Of

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.

Bibliometrics and Visualization of the Mechanisms of Parkinson's Diseases Based on Animal Models

2020 ◽  
Vol 20 (10) ◽  
pp. 1560-1568 ◽  
Author(s):  
Yan-Qiu Wang ◽  
Yi-Bing Chen ◽  
Dong Xu ◽  
Yuan-Lu Cui
Keyword(s):  
Oxidative Stress ◽  
Animal Models ◽  
Mitochondrial Protein ◽  
Bibliometric Method ◽  
Metabolism Disorder ◽  
Parkinson’S Diseases ◽  
Model Drug ◽  
6 Hydroxydopamine ◽  
Rats And Mice ◽  
Energy Metabolism Disorder

Objective: Energy metabolism disorder is one of the causes of Parkinson's disease (PD). Rodents, such as rats and mice are often used to establish animal models of PD. This paper used a bibliometric method to analyze the studies of rat and mouse PD models published between 2009 and 2018 in the Web of Science (WOS) database using CiteSpace V software. In addition, we conducted a literature review on the development status and research hotspots in this field in the past ten years. Methods: The related articles on rat and mouse PD models were retrieved from the WOS database, and an analysis of the keywords in these articles was conducted using CiteSpace V. A timeline graph was developed by the software in order to show the focus of researchers in the PD field. Results : A total of 8,636 articles were obtained. Results of the cluster analysis in the PD field such as neuroinflammation, oxidative stress, and autophagy, contributed to the systematic review about the pathogenesis of PD. At the same time, based on the property of the model drug, this review has summarized and compared different administration techniques and mechanisms of 6-hydroxydopamine (6- OHDA), 1-methyl-4-phenyl-1, 2, 4, 5-tetrahydropyridine (MPTP), paraquat and rotenone. Conclusion: According to the bibliometric analysis, studies on PD were focused on the mechanisms of oxidative stress, neuroinflammation, and autophagy. Activated microglia releases inflammatory cytokines; mitochondrial dysfunction is caused by oxidative damage of mitochondrial protein; abnormal autophagy-lysosome pathway can lead to abnormal protein deposition in dopaminergic neurons. In addition, although many animal models of PD have been established, there are some limitations of such models. Therefore, it is necessary to develop models that accurately mimic human PD.

3 (2) Factorial Design Assisted Crushed Puffed Rice-HPMC-Chitosan based Hydrodynamically Balanced System of Metoprolol Succinate

2020 ◽  
Vol 10 (3) ◽  
pp. 237-249
Author(s):  
Shashank Soni ◽  
Veerma Ram ◽  
Anurag Verma
Keyword(s):  
Drug Release ◽  
Factorial Design ◽  
Hydroxypropyl Methylcellulose ◽  
Batch Size ◽  
Metoprolol Succinate ◽  
Zero Order Kinetics ◽  
Two Factors ◽  
Puffed Rice ◽  
Model Drug

Introduction: Hydrodynamically balanced system (HBS) possesses prolonged and continuous delivery of the drug to the gastrointestinal tract which improves the rate and extent of medications that have a narrow absorption window. The objective of this work was to develop a Hydrodynamically Balanced System (HBS) of Metoprolol Succinate (MS) as a model drug for sustained stomach specific delivery. Materials and Methods: Experimental batches were designed according to 3(2) Taguchi factorial design. A total of 9 batches were prepared for batch size 100 capsules each. Formulations were prepared by physically blending MS with polymers followed by encapsulation into hard gelatin capsule shell of size 0. Polymers used were Low Molecular Weight Chitosan (LMWCH), Crushed Puffed Rice (CPR), and Hydroxypropyl Methylcellulose K15 M (HPMC K15M). Two factors used were buoyancy time (Y1) and time taken for 60% drug release (T60%; Y2). Results: The drug excipient interaction studies were performed by the thermal analysis method which depicts that no drug excipient interaction occurs. In vitro buoyancy studies and drug release studies revealed the efficacy of HBS to remain gastro retentive for a prolonged period and concurrently sustained the release of MS in highly acidic medium. All formulations followed zero-order kinetics. Conclusion: Developed HBS of MS with hydrogel-forming polymers could be an ideal delivery system for sustained stomach specific delivery and would be useful for the cardiac patients where the prolonged therapeutic action is required.

scholarly journals Semi-Crystalline Copolymer Hydrogels as Smart Drug Carriers: In Vitro Thermo-Responsive Naproxen Release Study

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 158
Author(s):  
Snežana Ilić-Stojanović ◽  
Ljubiša Nikolić ◽  
Vesna Nikolić ◽  
Slobodan Petrović ◽  
Violeta Oro ◽  
...  
Keyword(s):  
Drug Carrier ◽  
Drug Carriers ◽  
Xrd Analysis ◽  
Hplc Method ◽  
Potential Candidate ◽  
Swelling Kinetic ◽  
Model Drug ◽  
Xrd Techniques ◽  
Responsive Hydrogels

In this study, poly(N-isopropylacrylamide-co-2-hydroxypropyl methacrylate) hydrogels were synthesized using free radical initiated copolymerization method. Four hydrogels with different cross-linker concentrations were prepared. Semi-crystalline, cross-linked copolymer networks were confirmed by FTIR, SEM and XRD analysis. Variation of swelling behaviour was monitored gravimetrically and thermo-responsiveness has been noticed. An application of synthesized thermo-responsive hydrogels as carriers for the modulated release of anti-inflammatory model drug was investigated. Moreover, naproxen loading into these hydrogels was also determined using FTIR, SEM and XRD techniques and release was analyzed using HPLC method at simulated physiological conditions. Swelling kinetic and mechanism of water transport, as well as diffusion of naproxen through the hydrogels were analyzed. Thus, the aim of this work was to study various compositions of obtained hydrogels and their possibility of application as a thermo-responsive carrier for prolonged naproxen release in order to evaluate as a potential candidate for drug carrier in future pharmaceutical applications.

scholarly journals Reduced Graphene Oxide Fibre Electrodes for Drug Sensing

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 18
Author(s):  
Sutthima Sriprasertsuk ◽  
John R. Varcoe ◽  
Carol Crean
Keyword(s):  
Cyclic Voltammetry ◽  
Graphene Oxide ◽  
Carbon Fibre ◽  
Reduced Graphene Oxide ◽  
Limit Of Detection ◽  
Linear Range ◽  
Oxidation Peak ◽  
Reduced Graphene ◽  
Fibre Sensor ◽  
Model Drug

Reduced graphene oxide (rGO) fibre electrodes and their ability to sense paracetamol (as model drug) were studied. rGO was electrodeposited onto carbon fibre by two different approaches: potentiostatic deposition and cyclic voltammetry (CV) in the presence of graphene oxide solution. Carbon fibre electrodes coated with rGO (after five CV cycles) could sense paracetamol with an oxidation peak at 0.62 V (vs. Ag/AgCl). The limit of detection of this fibre sensor was found to be 36.3 µM with a linear range of 50–500 µM of paracetamol (R2 = 0.9901).

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