FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule13)
1. TITLE OF THE INVENTION:
ORAL SUSPENSION OF CEFDINIR
2. APPLICANT (S)
(a) NAME: WOCKHARDT LTD.
(b) NATIONALITY: INDIAN
(c) ADDRESS: Wockhardt Towers, Bandra-Kurla Complex, Bandra
(East), Mumbai - 400 051.
3. PREAMBLE TO THE DESCRIPTION
The present invention provides a powder for oral suspension comprising greater than 10% by weight of cefdinir or pharmaceutically acceptable salts thereof alongwith pharmaceutically acceptable excipients.
The following specification particularly describes the invention and the manner in which it is to be performed.
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4. Description
The present invention provides a powder for oral suspension comprising greater than 10% by weight of cefdinir or pharmaceutically acceptable salts thereof alongwith pharmaceutically acceptable excipients.
Cefdinir, an extended-spectrum third generation semi-synthetic cephalosporin, is meant for oral administration and characterized by broad antibacterial spectrum against gram-positive and gram-negative bacteria. It is commercially available under the trade name of Omnicef®. Chemically Cefdinir is [(-) 6R, 7R]-7-((Z)-2-(2-amino-4-thiazolyl)-2-hydroxyiminoacetamido)-3-vinyl-8-oxo-5-thia-1-azabicyclo [4.2.0]oct-2-ene-2-carboxylic acid (Formula I). Cefdinir is indicated for the treatment of patients with mild to moderate infections like community acquired pneumonia, acute exacerbations of chronic bronchitis, acute maxillary sinusitis, pharyngitis /tonsillitis and uncomplicated skin and skin structure infections caused by susceptible strains of microorganisms.


CH=CH,

FORMULA I
US Patent No. 4,559,334 provides 7-substituted-3-vinyl-3-cephem compounds and a pharmaceutically acceptable salt thereof.
US Patent No. 4,935,507 provides a crystalline form of cefdinir and process for preparation thereof.
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US Application No. 20050131079 provides a powder for oral suspension of cefdinir and method of preparing the same. Also provides powder for oral suspension of cefdinir comprising 6%, 8% and 10% by weight of cefdinir.
US Application No. 20060135500 provides oral pharmaceutical suspension of crystalline Cefdinir. Also provides kit for preparation of an oral pharmaceutical suspension containing crystal form C Cefdinir
US Application No. 20050245738 provides crystalline form of cefdinir, process for the preparation thereof and pharmaceutical composition containing crystalline cefdinir.
US 20060122165 relates to crystalline form of cefdinir and processes for the preparation thereof. Also provides pharmaceutical compositions comprising said crystalline form of cefdinir and to processes for preparing them.
PCT Application 2004104010 relates to a crystalline form of cefdinir and processes for producing the crystalline cefdinir. Also provides pharmaceutical compositions that include the 'Form R'.
PCT Application 2005100368 relates to amorphous 7-[2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamide]-3-vinyl-3-cephem-4-carboxylic acid (syn isomer), methods for its preparation, and pharmaceutical compositions comprising the same.
The present inventors while working on the development of cefdinir powder for suspension have surprisingly developed a powder for oral suspension comprising greater than 10 % by weight of cefdinir in admixture with pharmaceutically acceptable excipients and the said suspension after reconstitution was found to have desired consistency and pourability. Also the cefdinir oral suspension after
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reconstitution was found to be stable for 14 days when stored at room temperature (25°C)
In one of the aspects of present invention there is provided a powder for oral suspension comprising greater than 10% by weight of cefdinir in admixture with pharmaceutically acceptable excipients.
The powder for oral suspension comprises of cefdinir as an active ingredient. The said powder is prepared by sifting individually and then mixing a suitable diluent, buffering agent, preservative and viscosity-enhancing agent (Mixture 1). Cefdinir and a suitable glidant