title: Topical ocular delivery of fluoroquinolones.
abstract: BACKGROUND
  Topical fluoroquinolones are used in ophthalmology to treat ocular infections. They are bactericidal and inhibit bacterial DNA replication by inhibiting DNA gyrase and topoisomerase. Fluoroquinolones possess two ionizable groups: a carboxylic group (pKa1 = 5.5 - 6.34) and a heterocyclic group (pKa2 = 7.6 - 9.3), in the nucleus, which acquire charge at pH above and below the isoelectric point (pI = 6.75 - 7.78). At isoelectric point, fluoroquinolones remain unionized and show enhanced corneal penetration but exhibit reduced aqueous solubility and the drug may precipitate from aqueous solution. Aqueous ophthalmic solutions of fluoroquinolones are obtained by using hydrochloride or mesylate salt which is acidic and irritating to the eyes. Hence, pH of the solution is kept between 5 and 7 to ensure aqueous solubility and minimum ocular irritation.
  
  
  METHODS
  This review gives an overview of various physicochemical and formulation factors affecting the ocular delivery of fluoroquinolones and strategies for getting higher ocular bioavailability for ocular delivery of fluoroquinolones. These strategies could be employed to improve efficacy of fluoroquinolones in eye preparation.
  
  
  CONCLUSIONS
  Broad-spectrum antibacterials, such as the ophthalmic fluoroquinolones, are powerful weapons for treating and preventing potentially sight-threatening infections. The fourth-generation fluoroquinolones have quickly assumed an outstanding place in the ophthalmic applications. Especially valuable for their broad-spectrum coverage against Gram-positive and Gram-negative organisms, these agents have become the anti-infective of preference for many ophthalmologists. Moxifloxacin seems to be a promising powerful molecule among all fluoroquinolones for treatment of bacterial infections.
authors: Chitkara University, Chitkara College of Pharmacy , Chandigarh-Patiala National Highway, Rajpura-140401, Patiala, Punjab, India. pkpawar80@yahoo.com
authors: Pravin
authors: P
authors: Pawar
authors: Rajesh
authors: R
authors: Katara
authors: Sushil
authors: S
authors: Mishra
authors: Dipak K
authors: DK
authors: Majumdar
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D024841:Fluoroquinolones / Q000008:administration & dosage*; D006801:Humans; D009883:Ophthalmic Solutions
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D009883:Ophthalmic Solutions