Synthesis of Nanostructured Carboxycelluloses from Non-Wood Cellulose

Patent metadata

Field	Value
Publication number	US-2016130368-A1
Application number	US-201414895590-A
Country	US
Kind code	A1
Filing date	Jun 3, 2014
Priority date	Jun 3, 2013
Publication date	May 12, 2016
Grant date	—

Abstract

Disclosed herein is an improved process for the preparation of nanostructured oxidized/carboxy cellulose with high carboxy content and high yield, by subjecting non-wood, lignocellulose, sugarcane bagasse derived a-cellulose or cotton cellulose to oxidation at suitable temperature, wherein the particle shape is spherical, particle size of synthesized carboxy cellulose is in the range of 1-100 nm and degree of polymerization (DP) is in the range 50-70 Further the present invention provides pharmaceutical composition comprising of nanostructured oxidized/carboxy celluloses preferably 6-carboxy cellulose, and 2,3,6-tricarboxycellulose alone or in association with one or more pharmaceutically acceptable carrier(s) or excipient(s) for treatment of microbial infections. The carboxycelluloses were efficient in stabilizing multi-walled carbon nanotubes and single-walled carbon nanotubes in aqueous media.

First claim

1 . Spherical shaped Nanostructured carboxy cellulose with carboxy content in the range of 1.0% to 24% and molecular weight of 50-70 DP (degree of polymerization), wherein size of spherical carboxy cellulose is in the range of 10-100 nm.

2 . An improved process for the preparation of spherical shaped nanostructured carboxy cellulose with carboxy content in the range of 1.0% to 24% wherein the said process comprising the steps of;
a. oxidizing α-cellulose in the presence of 2:1 ratio (v/v) of 60-70% HNO 3 and 75-85% H 3 PO 4 and NaNO 2 (1.2-1.6 w/v %) at temperature ranging from 30° C.-80° C. for reaction time of 1 hr to 48 hrs to obtain nanostructured 6-carboxycellulose; b. optionally, oxidizing α-cellulose to 2,3,6 tricarboxycellulose.

3 . The process according to claim 2 , wherein cellulose used in step (a) and (b) is derived from sugarcane bagasse or from cotton.

4 . The process according to claim 2 , wherein the nanostructured carboxycellulose is in the form of spherical nanoparticles.

5 . The process according to claim 2 , wherein the size of nanoparticles of carboxy cellulose is in the range of 10-100 nm.

6 . The process according to claim 2 , wherein oxidation of α-cellulose or cotton cellulose to 2,3,6 tricarboxycellulose in step (b) was carried out by subjecting α-cellulose to oxidation in presence of sodium metaperiodate to obtain 2,3 dialdehyde cellulose; and oxidizing 2,3 dialdehyde cellulose in presence of nitroso producing agent 60-65% HNO3 and 85% P1 give range 75-85% H3PO4 in 2:1 (v/v) ratio, accompanied by NaNO2 in (1.2-1.6%) at temperature in the range 30° C.-80° C. for reaction time 15-20 hrs to afford nanostructured 2,3,6 tricarboxycellulose having carboxy content in the range 1-25% at C6 position of glucose unit of cellulose and in the range of 1-75% at C2 and C3 together of glucose unit of cellulose.

7 . The process according to claim 1 , wherein the nanostructured carboxycellulose exhibits solubility in dilute alkali solution selected from 0.1-15% of NaOH and organic solvents selected from the group consisting of acetonitrile, dimethylacetamide, dimethyl sulfoxide, dioxane, acetone, methanol, ethanol, chloroform, dichloromethane, tetrahydrofurane, toluene, dimethylformamide, pyridine.

8 . A pharmaceutical composition comprises nanoparticles of carboxy cellulose according to claim 1 , alone or along with one or more the pharmaceutically acceptable excipient(s) and/or vehicle(s), and/or carrier(s) useful for treating microbial infections wherein the bacterial species is selected from M. tuberculosis, E coli, B. subtilis S. aureus.

9 . A pharmaceutical composition according to claim 8 , alone or together with pharmaceutically acceptable excipient(s) and/or vehicle(s), wherein the MIC value is obtained in between 2-5 mg/ml.

10 . A method of inhibiting growth of microbes in mammals, comprising administrating nanoparticles of carboxy or oxidized cellulose according to claim 1 , alone or together with pharmaceutically acceptable excipient(s) and/or vehicle(s).

11 . A method of treating according to claim 8 , wherein the microbes are selected from the group consisting of bacteria, virus, fungi, parasites, yeast, mould; preferably bacteria selected from group M. tuberculosis, E coli, B. subtilis S. aureus.

12 . Use of carboxy cellulose according to claim 1 , as anti-microbial material in wound dressing gauze, hemostatic material, biocompatible material, biocomposites, detergent builder, catalyst, ion-exchange resin, polymer and hydrophobic cellulose nanoparticles.

Assignees

• Council Scient Ind Res

Inventors

• Varma Anjanikumar Jyoti-Prasad
• Sharma Priyanka Radheyshyam
• Sarkar Dhiman

Classifications

• A61K31/717

  Celluloses · CPC title

• C08B11/12 Primary

  substituted with carboxylic radicals {, e.g. carboxymethylcellulose [CMC]} · CPC title

• Y02A50/30

  Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change · CPC title