title: Site specific chronotherapeutic drug delivery systems: a patent review.
abstract: Oral dosage forms are known to provide a zero order or first order release in which the drug is released at a substantially steady rate of release per unit of time. However, there are instances where maintaining a constant blood level of a drug is not desirable. In such cases a pulsatile drug delivery may be more advantageous. Pulsatile drug delivery systems can be classified into site-specific systems in which the drug is released at the desired site within the intestinal tract (e.g., the colon), or time-controlled devices in which the drug is released after a well-defined time period. Environmental factors like pH or enzymes present in the intestinal tract control the release of a site-controlled system whereas the drug release from time-controlled systems is controlled primarily by the delivery system and not by the environment. The delayed liberation of orally administered drugs has been achieved through a range of formulation approaches, including single or multiple unit systems provided with release-controlling coatings, capsular devices and osmotic pumps. Our aim in this review is to outline the rational and prominent design strategies behind site-specific oral pulsatile delivery. The present article provides a good patent review regarding the Site Specific Chronotherapeutic Drug Delivery Systems.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Jamia Hamdard, Hamdard Nagar, New Delhi - 110 062, India.
authors.forename: Nitin
authors.initials: N
authors.lastname: Saigal
authors.forename: Sanjula
authors.initials: S
authors.lastname: Baboota
authors.forename: Alka
authors.initials: A
authors.lastname: Ahuja
authors.forename: Javed
authors.initials: J
authors.lastname: Ali
mesh_terms: D000284:Administration, Oral; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D006801:Humans; D010330:Patents as Topic; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D013678:Technology, Pharmaceutical / Q000379:methods*; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D004364:Pharmaceutical Preparations