24/06/2005 - Controller General of Patents, Designs, and Trade Marks

(21) Application No. 613/DEL/2003 A (22) Date of filing of Application: 16/04/2003
(54) Title of the invention: “A Process For The Preparation of pH Sensitive, Mucoadhesive Hydrogel
Nanoparticles for Systemic Delivery of Water Soluble Drugs Through
Oral Route”
(51) International Classification 7 :
A61K 009/14; A61K 9/16; A61K47/32;
A61K 9/51; A61K 9/54
(30) Priority Data :
(31) Document No.:NIL
(32) Date : NIL
(33) Name of convention country : NIL
(66) Filed U/s 5(2) : NIL
(61) Patent of addition to application No. :
NA
(62) Filed on : NA
(63) Divisional to Application No. :NIL
(64) Filed on : NA
Total Pages: 14
(57) Abstract:
(71) Name of the applicant:
University of Delhi,
Address of the Applicant:
Department of Chemistry, Delhi–110007,
(72) Name of the Inventor:
Prof. MAITRA,Amarnath;
MOZUMDAR, Sobho;
MITRA, Susmita;
BHARALI, Dhruba Jyoti;
This invention relates to a process for the preparation of pH sensitive, mucoadhesive,
hydrogel nanoparticles for the systemic delivery of water soluble drugs through oral routes
comprising mainly the steps of:
Step 1 –dissolving a surfactant in oil to obtain reverse micelles,
Step 2 –adding an aqueous solution of vinyl pyrrolidone (VP), n–isopropyl acrylamide
(NIPAAM) and acrylic acid (AA) monomers in the molar ratio of 40:30:30
(VP:NIPAAM:AA), a cross–linking agent, initiator, activator and water to said reverse
micelles to form an optically clear and transparent reverse micellar solution,
Step 3 –subjecting said solution to polymerization in the presentce of an inert gas to obtain
nanoparticles having uniform size between 10 mm to 50 mm diameter with low
polydispersity,
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