title: Topical drug delivery systems: a patent review.
abstract: BACKGROUND
  Topical administration is the favored route for local delivery of therapeutic agents due to its convenience and affordability. The specific challenge of designing a therapeutic system is to achieve an optimal concentration of a certain drug at its site of action for an appropriate duration.
  
  
  METHODS
  This review summarizes innovations from the past 3 years (2012-2015) in the field of topical drug delivery for the treatment of local infections of the vagina, nose, eye and skin. The review also throws some light on the anatomy and physiology of these organs and their various defensive barriers which affect the delivery of drugs administered topically.
  
  
  CONCLUSIONS
  Topical administration has been gaining attention over the last few years. However, conventional topical drug delivery systems suffer from drawbacks such as poor retention and low bioavailability. The successful formulation of topical delivery products requires the careful manipulation of defensive barriers and selection of a soluble drug carrier. Extensive research is required to develop newer topical drug delivery systems aiming either to improve the efficacy or to reduce side effects compared to current patented systems.
authors.affiliation: a Department of Pharmaceutical Sciences and Drug Research , Punjabi University , Patiala , India.
authors.forename: Deepinder
authors.initials: D
authors.lastname: Singh Malik
authors.affiliation: a Department of Pharmaceutical Sciences and Drug Research , Punjabi University , Patiala , India.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Mital
authors.affiliation: a Department of Pharmaceutical Sciences and Drug Research , Punjabi University , Patiala , India.
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Kaur
mesh_terms: D000287:Administration, Topical; D000818:Animals; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D015195:Drug Design; D006801:Humans; D010330:Patents as Topic; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000378:metabolism
chemical_list: D004337:Drug Carriers; D004364:Pharmaceutical Preparations
keywords: Hydrogels; nano-carriers; sustained release; topical delivery