scholarly journals Effect of stearic acid on the properties of metronidazole/methocel K4M floating matrices

2009 ◽  
Vol 45 (3) ◽  
pp. 497-505 ◽  
Author(s):  
Belem Lara-Hernández ◽  
Alejandra Hernández-León ◽  
Leopoldo Villafuerte-Robles

The properties of metronidazole/Methocel K4M sustained release floating tablets have been studied varying the proportion of the lubricant, stearic acid, on formulations with and without sodium bicarbonate. The variables studied include technological properties of the tablets such as tablet hardness and ejection pressure, the drug release profile, the hydration kinetics and the floating behaviour. The presence of stearic acid and sodium bicarbonate improves the floating behaviour for more than 8 hours. The hydration volume, the tablet hardness and the ejection pressure decrease as the stearic acid content increases and the polymer content decreases. Drug dissolution increases with increasing proportions of stearic acid and decreasing proportions of the polymer in the tablets. The presence of sodium bicarbonate extends the differences in dissolution produced by stearic acid. These results are attributed to decreasing matrices coherence with an increasing quantity of stearic acid and a reducing polymer proportion. The carbon dioxide bubbles produced by sodium bicarbonate expand the matrices facilitating the dissolution, although their presence obstructs also the diffusion path through the hydrated gel layer.

Pharmaceutics ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 417 ◽  
Author(s):  
Emese Sipos ◽  
Nóra Kósa ◽  
Adrienn Kazsoki ◽  
Zoltán-István Szabó ◽  
Romána Zelkó

Aceclofenac-loaded poly(vinyl-pyrrolidone)-based nanofiber formulations were prepared by electrospinning to obtain drug-loaded orally disintegrating webs to enhance the solubility and dissolution rate of the poorly soluble anti-inflammatory active that belongs to the BCS Class-II. Triethanolamine-containing ternary composite of aceclofenac-poly(vinyl-pyrrolidone) nanofibers were formulated to exert the synergistic effect on the drug-dissolution improvement. The composition and the electrospinning parameters were changed to select the fibrous sample of optimum fiber characteristics. To determine the morphology of the nanofibers, scanning electron microscopy was used. Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) were applied for the solid-state characterization of the samples, while the drug release profile was followed by the in vitro dissolution test. The nanofibrous formulations had diameters in the range of few hundred nanometers. FT-IR spectra and DSC thermograms indicated the amorphization of aceclofenac, which resulted in a rapid release of the active substance. The characteristics of the selected ternary fiber composition (10 mg/g aceclofenac, 1% w/w triethanolamine, 15% w/w PVPK90) were found to be suitable for obtaining orally dissolving webs of fast dissolution and potential oral absorption.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Matej Pavli ◽  
Julijana Kristl ◽  
Andrej Dolenc ◽  
Alenka Zvonar ◽  
Franc Vrečer ◽  
...  

AbstractOur aim was to investigate the texture of hydrated biopolymer matrices that are now being considered in the design of pharmaceutical controlled-release dosage forms, in order to determine their influence on the release of an active compound. Prolonged release of pentoxifylline, a highly soluble drug, is needed for once-daily administration to achieve its therapeutic effect. For this purpose, pentoxifylline was incorporated in a polymer matrix made of a combination of xanthan and locust bean gum (XLBG), both of which are of biotechnological origin. Different methods were used to investigate the interplay of the XLBG gel structure characteristics in the absence and presence of 200 mM CaCl2 on pentoxifylline release: drug-release studies, determination of swelling, erosion, and viscoelasticity of the gel, as well as its texture analysis and microscopic imaging. From the results obtained, the following conclusions can be drawn: the pentoxifylline release from XLBG matrices in water was prolonged for 24 h whereas from the control lactose formulation was completed within 30 min. The presence of Ca2+ ions in water resulted in faster pentoxifylline release, in spite of less swelling and erosion. However, the rheology, texture analysis and scanning electron microscopy revealed that in the presence of the Ca2+ ions the gel layer of the XLBG was more cohesive and thinner, as the attraction for water molecules was lower due to the condensation of counter-ions on the xanthan carboxylic-moieties, and consequently greater interpolymer interactions. Therefore, relatively larger amounts of free water molecules were available within the XLBG hydrogel in the presence of Ca2+, allowing faster drug dissolution and diffusion. Here, the presence of Ca2+ ions had a completely opposite effect on XLBG gel structure and drug release in comparison with other more investigated matrix polymers like alginate or non-ionic cellulose ethers. A firm matrix structure that is accompanied by low swelling and erosion cannot guarantee a more prolonged drug release.


1970 ◽  
Vol 7 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Ferdous Khan ◽  
Md Shaikhul Millat Ibn Razzak ◽  
Md Ziaur Rahman Khan ◽  
Kazi Rashidul Azam ◽  
Sams Mohammad Anowar Sadat ◽  
...  

This investigation describes the preparation and in vitro evaluation of gastroretentive floating tablets of theophylline. Hydrophilic polymer METHOCEL K4M was used for its gel forming and release controlling properties. Sodium bicarbonate and citric acid were incorporated as gas generating agents. The effects of soluble components (sodium bicarbonate and citric acid), gel forming agent (METHOCEL K4M) and dose variation on drug release profile and floating properties were investigated. It has been observed that in all cases increase of the amount of floating agent caused a decrease of the floating lag time. Increase of theophylline load showed an increase of the floating lag time, which was independent of floating agent content. The release mechanisms were explored and explained with zero order, first order, Higuchi, Korsmeyer and Hixon-Crowell equations. The release rate, extent and mechanisms were found to be governed by the content of polymer and floating agent. The content of active ingredient was also a vital factor in controlling drug release pattern. It was found that polymer content and amount of floating agent significantly affected the time required for 50% of drug release (T50%), percentage drug release after 8 hours, release rate constant, and diffusion exponent (n). Kinetic modeling of dissolution profiles revealed that the drug release mechanism could range from diffusion controlled to case II transport, which was mainly dependent on presence of relative amount of theophylline, polymer and floating agent. Key words: Gastroretention, Floating tablet, Theophylline  DOI = 10.3329/dujps.v7i1.1220 Dhaka Univ. J. Pharm. Sci. 7(1): 65-70, 2008 (June)


2012 ◽  
Vol 2 (1) ◽  
pp. 11-17
Author(s):  
Manish Jaimini ◽  
Yuveraj Singh Tanwar ◽  
Birendra Srivastava

Floating matrix tablets of losartan potassium were developed with an aim to prolong its gastric residence time and increase the bioavailability of drug. Rapid gastrointestinal transit could result in incomplete drug release from the drug delivery system above the absorption zone leading to diminished efficacy of the administered dose. The tablets were prepared by wet granulation technique, using polymers Methocel K15 and Methocel K100 in combination with other standard excipients. Sodium bicarbonate was incorporated as gas generating agent. The effects of sodium bicarbonate and polymers on drug release profile and floating properties were investigated. It was found that viscosity of Methocel K15 and Methocel K100 along with sodium bicarbonate had significant impact on the release and floating properties of the delivery system. The decrease in the release rate was observed with an increase in the viscosity of the polymeric system. Polymer with high viscosity Methocel K100 was shown to be beneficial than low viscosity polymer Methocel K15 in improving the floating properties of gastric floating drug delivery system (GFDDS). The observed difference in the drug release and floating properties of GFDDS could be attributed to the difference in the basic properties of two polymers, Methocel K15 and Methocel K100 due to their water uptake potential and functional group substitution. The release mechanism were explored and described with zero-order, first-order and Korsmeyer-Peppas equations. The drug release profiles and buoyancy of the floating tablets were stable when stored at 40°C/75% RH for 6 months.DOI: http://dx.doi.org/10.3329/icpj.v2i1.12872 International Current Pharmaceutical Journal 2012, 2(1): 11-17 


2009 ◽  
Vol 59 (3) ◽  
pp. 301-312 ◽  
Author(s):  
Noushin Bolourchian ◽  
Naghmeh Hadidi ◽  
Seyed Foroutan ◽  
Bijan Shafaghi

Development and optimization of a sublingual tablet formulation for physostigmine salicylateThis study is aimed to design and optimize a sublingual tablet formulation of physostigmine salicylate, an effective drug in Alzheimer's disease and nerve gas poisoning, by means of the D-optimal experimental design methodology. Polyvinyl pyrrolidone, lactose, starch 1500 and sodium starch glycolate were used in the formulations as independent variables. Tablets were prepared by the direct compression method and evaluated for their physical properties (tablet hardness, disintegration time and friability), which were regarded as responses in a D-optimal design. Due to the significance of the special cubic model for data fitted, compared to other models, it was used to examine the obtained results. Response surface plots were plotted to study the tablet properties and the optimized overlay plot was generated based on the results and targets considered for the responses. After verification of the optimum checkpoint formulations, an optimized formulation was chosen due to its desirable physical properties and closely observed and predicted values. Drug assay, content uniformity of the dosage unit, drug dissolution and accelerated stability studies were done on the optimum formulation as further experiments. All the obtained results complied with the requirements of a sublingual tablet formulation.


Author(s):  
Neeraj Kumar ◽  
Harish Dureja ◽  
Amrish Chandra

Lung cancer is the second most frequent cancer and among the top cause of death worldwide. Chemotherapy is the main therapeutic option for non-small-cell lung cancer (NSCLC), which accounts for the majority of all lung malignancies. The aim of the current work was to develop a tablet formulation having increased drug release profile to improve the bioavailability in order to reduce the dose of the drug. In this present study, Erlotinib tablet was prepared using micronization technique which showed increase drug release profile. Film-coated tablets containing Erlotinib hydrochloride (150 mg) were prepared by dry granulation technique and coated using Opadry ready-mix. Tablets were characterized for Hardness, Friability, Potency and Drug release profile. Drug release was checked in 0.1 N HCL containing 0.5 % SLS and biorelevant dissolution media up to 60 minutes. Tablets of the selected batch were subjected to dissolution in biorelevant media and compare with reference product. The improvement in the drug release was observed in the biorelevant media in comparison with reference product. The in-vitrodissolution data demonstrated the potential of micronization technology to prepare tablets with improved bioavailability of the drug.


2006 ◽  
Vol 28 (62) ◽  
Author(s):  
Antonio Zenon Antunes Teixeira ◽  
Garima Saini ◽  
Alexander Macgregor

The aims of this study were to develop a predictive immediate release tablet formulation system for soluble drugs. Ranitidine hydrochloride, silicifiedmicrocrystallinecellulose (SMCC), polyplasdone XL and hydroxyprophylmethylcellulose (HPMC) E6 were evaluated for powder properties. The effects of binder (HPMC E6) and disintegrant (Polyplasdone XL) were investigated. A 32 factorial design was applied to optimize the drug release profile. The amount of binder and disintegrant were selected as independent variables. The times required for 50% (t50) and 80% (t80) drug dissolution and similarity factor (f2) were chosen as dependent variables. The results of factorial design indicated that a high amount of binder and low amount of disintegrate favored the preparation of drug release. The difference (f1) and similarity (f2) factors were used to measure the relative error and the closeness (similarity) between the factorial design batches and brand name drugs. No significant difference was observed between the brand drug and ranitidine batches F1, F2, F5, F6 and F9. Ranitidine batch F2 yielded the highest value of f2(71%)and the lowest of f1(10%). This research indicates that the proper amount of binder and disintegrant can produce drug dissolution profiles comparable to their brands.


2021 ◽  
Vol 10 (4) ◽  
pp. 46-53
Author(s):  
I. D. Kasymov ◽  
A. V. Basevich

Introduction. The article presents the results of studying the technological properties of individual excipients widely used in the compositions of existing orally dispersed tablets (ODT) for subsequent planning a multifactorial experiment. Samples of excipients were analyzed according to such pharmacopoeial indicators as description, flowability, bulk density, compressibility, fractional composition, solubility in water.Aim. The aim of the work is to create a list and study the technological properties of candidate substances for the role of auxiliary substances in the composition being developed by the ODT.Materials and methods. The technological properties of excipient samples were studied according to the methods of the State Pharmacopoeia of the XIV edition using the flowability tester GTL (ERWEKA, Germany), the bulk density tester SVM 221 (ERWEKA, Germany), the tablet press PGR-10 (LabTools, Russia) and the tablet hardness tester TBH 125 TDP (ERWEKA, Germany).Results and discussion. As a result of the study, experimental data on the technological properties of excipient samples were collected, and the selected samples were compared according to pharmaceutical and technological indicators.Conclusion. In the course of the study, a list of auxiliary substances for the development of the composition of ODT was formed and studies of their technological properties were carried out. The obtained experimental data will allow to develop an optimal matrix of a multifactorial experiment for the development of the composition of ODT and justify the choice of excipients.


2012 ◽  
Vol 15 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Md Nazmul Hussain ◽  
Md Abdullah Al Masum ◽  
Sharmin Akhter ◽  
Florida Sharmin ◽  
Md Selim Reza

Gastro retentive floating tablet of Simvastatin was prepared by direct compression technique using Methocel K4M as the rate controlling polymer. The hydrophilic cellulose derivative, Methocel K4M was evaluated for its gel forming and release controlling properties. Sodium bicarbonate and citric acid were incorporated as gas generating agents. The effects of soluble components (sodium bicarbonate and citric acid) and gel forming agents on drug release profile and floating properties were investigated. The tablets from all formulations were evaluated for thickness, diameter, weight variation, hardness, and friability. The tablets were also tested for the buoyancy studies and in vitro drug release studies. The drug release study was evaluated for eight hours using USP XXII paddle-type dissolution apparatus using 0.1N HCl with 1% Sodium Lauryl Sulphate as dissolution medium. The release mechanisms were explored and explained with zero order, first order, Higuchi, Hixon Crowell and Korsmeyer equations. The release rate, extent and mechanisms were found to be governed by the polymer content. It was found that the mean dissolution time, percentage drug release, release rate constant and diffusion exponent were influenced significantly by the amount of polymer incorporation. DOI: http://dx.doi.org/10.3329/bpj.v15i2.12575 Bangladesh Pharmaceutical Journal 15(2): 119-126, 2012


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