Polymorphisms and patent, market, and legal battles: Cefdinir case study

The ongoing patent battle relating to Cefdinir polymorphism and crystalline forms is described from a scientific point of view. This case study illustrates some of the strategies adopted by generic bulk manufacturers to challenge originator's patents on polymorphic forms

Crystalline(6R,7R)-7-[1,2,4]triazolo-3-yl)-2-[(Z)-trityloxyimino]-acety-lamino)- 3-[(R)-1\u2019-tert-butoxycarbonyl-2-oxo-[1,3\u2019]bipyrrolidinyl-(3E)ylidenemethyl-8-oxo- 5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydril ester; its manufacturing and use

new crystalline formBREVETTO CONCESS

PROCESSO DI PREPARAZIONE DI TIGECICLINA

Si descrive un processo per la preparazione di tigeciclina per reazione di 9-amminominociclina con un derivato N-protetto di tert-butilglicina seguita da rimozione del gruppo protettivo in condizioni blande

Crystalline form of Cefdinir ammonium salt as an intermediate for the preparation of pure Cefdinir

The invention relates to crystalline Cefdinir ammonium salt of formula (I)

Solid state photoreactivity of a dioxolenone methyl ester

The dioxolenonemethyl moiety of the oral penem prodrug FCE 25199 (1) was found to be a source of photochemical lability in the solid state. Reactions centered on the formation and decomposition of a hydroperoxide (3) have been observed and rationalized. Expedients have been devised to improve the shelf-life of crystalline 1 up to acceptable levels

Development of a practical high-yield industrial synthesis of pergolide mesylate

The development of a high-yield and low environmental impact synthesis able to deliver highly pure pergolide mesylate 1 is described. The process [seven chemical steps (four telescoped), three steps of isolation of intermediate, and only one drying] affords pergolide mesylate 1 in 75-81% overall yield from dihydrolysergic acid 4 with > 99.8% purity

Cefdinir: A comparative study of anhydrous vs. monohydrate form Microstructure and tabletting behaviour

Anhydrous cefdinir (AC) vs. monohydrated cefdinir (MHC) was compared in order to be used as antimicrobial in therapeutics. Different techniques have been used to characterize physically AC and MHC, and also a complete microstructural analysis of raw materials was carried out. Cefdinir and Maltodextrin QDM (R) 500 (3:2) formulations were compressed in order to obtain tablets with typical dose of Cefdinir, i.e. 300 mg. Dissolution profiles were obtained for both AC and MHC tablets. Finally tablet X-ray diffraction was performed to ensure the stability of the monohydrated form after tabletting being clearly different in both AC and MHC crystals. AC crystal structure was agreed with the known pattern of anhydrous Cefdinir described in the literature. Microstructural analysis showed large differences in specific surface area (SSA), confirmed by mercury intrusion. Crystal structures of both AC and MHC were stable under mixing, compression and storing processes. Dissolution profiles were faster for hydrate form, probably related to microstructural properties of the crystal which remained after tabletting. In conclusion, it is possible to isolate Cefdinir in two forms anhydrous and monohydrate, well characterized and differentiated. The use of this later improves dissolution of tablet dosage form due to the lack of interconversion during tablet manufacture. (c) 2006 Elsevier B.V. All rights reserved