Critical re-investigation of the alditol acetate method for analysis of substituent distribution in methyl cellulose

The complexity of the substituent distribution in polysaccharide derivatives is discussed and defined. The challenges regarding analytical characterization that results from various interrelated categories of distributions, including molecular weight, chemical composition, and microstructure, are outlined. Due to these convoluted levels of complexity, results should always be interpreted with carefulness. Various analytical approaches which have been applied to starch and cellulose derivatives are recapped, including enzymatic, mass spectrometric, and chromatographic methods. The relation of heterogeneities of first and second order among and along the polysaccharide chains is addressed. Finally, examples of own analytical work on cellulose ethers are presented, including the MS analysis of methyl cellulose (MC) blends and fractionation studies of fully esterified MC, especially its 4-methoxybenzoates by gradient HPLC on normal phase. Preparative fractionation according to the degree of substitution (DS) allows follow-up analysis in order to get more detailed information on the substituent distribution in such sub-fractions.

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Solid-state NMR studies of methyl celluloses. Part 2: Determination of degree of substitution and O-6 vs. O-2/O-3 substituent distribution in commercial methyl cellulose samples

Cellulose ◽

10.1007/s10570-009-9304-2 ◽

2009 ◽

Vol 16 (6) ◽

pp. 1159-1166 ◽

Cited By ~ 6

Author(s):

Andrea Karrasch ◽

Christian Jäger ◽

Bodo Saake ◽

Antje Potthast ◽

Thomas Rosenau

Keyword(s):

Solid State ◽

Solid State Nmr ◽

Methyl Cellulose ◽

Degree Of Substitution ◽

Nmr Studies ◽

Substituent Distribution

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Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053085 ◽

1982 ◽

Vol 40 ◽

pp. 56-57

Author(s):

J. N. Turner ◽

D. N. Collins

Keyword(s):

Guinea Pigs ◽

Room Temperature ◽

Dose Group ◽

Methyl Cellulose ◽

Uranyl Acetate ◽

Target Organ ◽

Office Building ◽

Lead Citrate ◽

Control Groups ◽

Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

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Hepatoprotective Activity of Calotropis gigantea Root Bark Experimental Liver Damage Induced by D-Galactosamine in Rats

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2008.1.3.12 ◽

1970 ◽

Vol 1 (3) ◽

pp. 281-286

Author(s):

Pradeep Deshmukh ◽

Tanaji Nandgude ◽

Mahendra Singh Rathode ◽

Anil Midha ◽

Nitin Jaiswal

Keyword(s):

Methyl Cellulose ◽

Hepatoprotective Activity ◽

Albino Rats ◽

Root Bark ◽

Significant Activity ◽

Alcoholic Extract ◽

Calotropis Gigantea ◽

Wistar Albino Rats ◽

Experimental Liver ◽

Hepatoprotective Drug

The suspensions of alcoholic extract of root bark of the plant Calotropis gigantea in 0.6% carboxy methyl cellulose (CMC) were evaluated for hepatoprotective activity in Wistar albino rats by inducing hepatic injury with D-galactosamine (400 mg/kg). Alcoholic extract of root bark of the plant Calotropis gigantea at an oral dose of 200 mg/kg and 400 mg/kg exhibited a significant (P<0.001, P<0.01 and P<0.05) protection effect by normalizing the levels of aspartate amino transferase (ASAT/ GOT), alanine amino transferase (ALAT/GPT), alkaline phosphatase (ALP), total bilirubin (TB), lactate dehydrogenase (LDH), which were significantly (P<0.001) increased in rats by treatment with 400 mg/kg i.p. of D-galactosamine. Silymarin (25 mg/kg), a known hepatoprotective drug used for comparison exhibited significant activity (P<0.001).

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Formulation and In vitro Release Characterization of Metoprolol Succinate Extended Release Tablets

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2011.4.4.3 ◽

2012 ◽

Vol 4 (4) ◽

pp. 1537-1543

Author(s):

Sakthikumar T ◽

Rajendran N N ◽

Natarajan R

Keyword(s):

Drug Release ◽

Extended Release ◽

In Vitro Release ◽

Methyl Cellulose ◽

Wet Granulation ◽

Direct Compression ◽

Metoprolol Succinate ◽

Extended Release Formulations ◽

Vitro Release

The present study was aimed to develop an extended release tablet of metoprolol Succinate for the treatment of hypertension. Four extended release formulations F1-F4 were developed using varying proportions of hydroxylpropyl-methylcellulose K100M, sodium carboxy methyl cellulose and Eudragit L30 D55 by wet granulation. Five extended release formulations F5-F9 containing HPMC K100M and HPMC 5 cps in varying concentration were developed by direct compression. The physicochemical and in vitro release characteristics of all the formulations were investigated and compared. Two formulations, F7 and F8 have shown not more 25% drug release in 1st h, 20%-40% drug release at 4th hour, 40%-60% drug release at 8th hour and not less than 80% at 20th hour and the release pattern conform with USP specification for 24 hours extended release formulation. It can be conclusively stated that optimum concentration of HPMC K100M (58%-65%) by direct compression method can yield an extended release of metoprolol succinate for 24 hours.

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Novel Herbal Topical Patch Containing Curcumin and Arnica montana for the Treatment of Osteoarthritis

Current Rheumatology Reviews ◽

10.2174/1573397115666190214164407 ◽

2020 ◽

Vol 16 (1) ◽

pp. 43-60 ◽

Cited By ~ 1

Author(s):

Priyanka Kriplani ◽

Kumar Guarve ◽

Uttam Singh Baghel

Keyword(s):

Drug Release ◽

Factorial Design ◽

Analgesic Activity ◽

Ex Vivo ◽

Hydroxypropyl Methylcellulose ◽

Methyl Cellulose ◽

World Population ◽

Jojoba Oil ◽

Arnica Montana ◽

Transdermal Patches

Background: Osteoarthritis (OA) ranks fifth among all forms of disability affecting 10% of the world population. Current treatments available are associated with multiple side effects and do not slow down the progression of the disease. Moreover, no such effective treatment is available to date in various systems of medicine to treat osteoarthritis. Curcumin and Arnica have shown evident clinical advances in the treatment of osteoarthritis. Objective: The aim of the present study was to design, optimize and characterize novel herbal transdermal patches of curcumin and Arnica montana using factorial design. Methods: A multiple factorial design was employed to investigate the effect of hydroxypropyl methyl cellulose, ethyl cellulose and jojoba oil on elongation and drug release. Transdermal patches were evaluated by FTIR, DSC, FESEM, ex vivo drug permeation, anti osteoarthritic activity and analgesic activity. Results: Independent variables exhibited a significant effect on the physicochemical properties of the prepared formulations. The higher values of drug release and elongation were observed with the higher concentration of hydroxypropyl methylcellulose and jojoba oil. Anti osteoarthritic activity was assessed by complete Freund's adjuvant arthritis model; using rats and analgesic activity by Eddy's hot plate method, using mice. Combination patch exhibited good anti osteoarthritic and analgesic activity as compare to individual drug patches. Conclusion: The design results revealed that the combination patch exhibited good physicochemical, anti osteoarthritic and analgesic activity for the treatment of osteoarthritis in animals. More plants and their combinations should be explored to get reliable, safe and effective formulations that can compete with synthetic drugs.

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Optimization and Quality by Design Approach for Piroxicam Fast Dissolving Tablet Formulations Using Box-Behnken Design

Current Drug Therapy ◽

10.2174/1574885514666190409102614 ◽

2020 ◽

Vol 15 (2) ◽

pp. 152-165

Author(s):

Harekrishna Roy ◽

Sisir Nandi ◽

Ungarala Pavani ◽

Uppuluri Lakshmi ◽

Tamma Saicharan Reddy ◽

...

Keyword(s):

Quality By Design ◽

Methyl Cellulose ◽

Statistical Technique ◽

Quadratic Model ◽

Contour Plot ◽

Compression Technique ◽

Disintegration Time ◽

Box Behnken Design ◽

The Impact ◽

The Relationship

Background: The present study deals with the formulation and optimization of piroxicam fast dissolving tablets and analyzes the impact of an independent variable while selecting the optimized formulation utilizing Quality by Design (QbD) and Box-Behnken Design (BBD). Methods: Seventeen formulations were prepared by direct compression technique by altering the proportion of cross carmellose sodium, spray dried lactose and hydro propyl methyl cellulose (HPMC K4M). The BBD statistical technique was used to optimize formulations and correlate the relationship among all the variables. Also, the powder mixture characteristics and tablet physiochemical properties such as hardness, friability, drug content, Disintegration Time (DT) and dissolution test were determined using 900 ml of 0.1N HCl (pH-1.2) at 37 ± 0.5°C. Results: Significant quadratic model and second order polynomial equations were established using BBD. To find out the relationship between variables and responses, 3D response surface and 2D contour plot was plotted. A perturbation graph was also plotted to identify the deviation of the variables from the mean point. An optimized formula was prepared based on the predicted response and the resulting responses were observed to be close with the predicted value. Conclusion: The optimized formulation with the desired parameter and formulation with variables and responses can be obtained by BBD and could be used in the large experiment with the involvement of a large number of variables and responses.

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Properties of Calcium Sulfoaluminate Cement Mortar Modified by Hydroxyethyl Methyl Celluloses with Different Degrees of Substitution

Molecules ◽

10.3390/molecules26082136 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2136

Author(s):

Shaokang Zhang ◽

Ru Wang ◽

Linglin Xu ◽

Andreas Hecker ◽

Horst-Michael Ludwig ◽

...

Keyword(s):

Compressive Strength ◽

Flexural Strength ◽

Bond Strength ◽

Cement Mortar ◽

Retention Rate ◽

Methyl Cellulose ◽

Tensile Bond Strength ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate ◽

Cement Mortars

This paper studies the influence of hydroxyethyl methyl cellulose (HEMC) on the properties of calcium sulfoaluminate (CSA) cement mortar. In order to explore the applicability of different HEMCs in CSA cement mortars, HEMCs with higher and lower molar substitution (MS)/degree of substitution (DS) and polyacrylamide (PAAm) modification were used. At the same time, two kinds of CSA cements with different contents of ye’elimite were selected. Properties of cement mortar in fresh and hardened states were investigated, including the fluidity, consistency and water-retention rate of fresh mortar and the compressive strength, flexural strength, tensile bond strength and dry shrinkage rate of hardened mortar. The porosity and pore size distribution were also analyzed by mercury intrusion porosimetry (MIP). Results show that HEMCs improve the fresh state properties and tensile bond strength of both types of CSA cement mortars. However, the compressive strength of CSA cement mortars is greatly decreased by the addition of HEMCs, and the flexural strength is decreased slightly. The MIP measurement shows that HEMCs increase the amount of micron-level pores and the porosity. The HEMCs with different MS/DS have different effects on the improvement of tensile bond strength in different CSA cement mortars. PAAm modification can improve the tensile bond strength of HEMC-modified CSA cement mortar.

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