On December 2, 2004, Faour, Joaquina; Vergez, Juan A. published a patent.Name: 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate The title of the patent was Breakable, controlled-release tablets comprising a preformed passage. And the patent contained the following:
The invention relates to a simple and improved osmotic device for the controlled release of an active agent from the core into the use environment. According to the invention, the active agent is first released through a preformed passage and, subsequently, through a second passage which is formed in situ. Optionally, the size of one or both of the passages increases during the use of the osmotic device. Moreover, the preformed passage and/or the second passage increases the release speed of the active agent and enables the release of larger particles containing the active agent and/or the release of active agents which are essentially insoluble in the use environment. Owing to the in situ formation of the second opening, the device can release a greater percentage of active agent than that which would be released without said second opening. The experimental process involved the reaction of 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate(cas: 86393-32-0).Name: 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate
The Article related to drug delivery tablet controlled release, Pharmaceuticals: Pharmaceutics and other aspects.Name: 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid hydrochloride hydrate
Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics