title: Nanomedicine for glaucoma: liposomes provide sustained release of latanoprost in the eye.
abstract: OBJECTIVE
  To report the development and therapeutic evaluation of a liposomal nanocarrier for sustained release of latanoprost, in the rabbit eye.
  
  
  METHODS
  We fabricated latanoprost-loaded egg-phosphatidylcholine (EggPC) liposomes using the film hydration technique. The delivery vehicles were nano-sized (Z avg = 109 ± 18 nm), had a narrow poly dispersity index (PDI = 0.19 ± 0.04), and a very high loading efficiency (94% ± 5%). Based on in vitro data, we evaluated this formulation for lowering intraocular pressure (IOP) in rabbit eyes. Following a single subconjunctival injection of the latanoprost loaded formulation, the eyes were clinically monitored and the IOP recorded.
  
  
  RESULTS
  Latanoprost-loaded EggPC liposomes demonstrated a high drug/lipid mole ratio of 0.181, remained stable for at least 6 months on storage (4°C), and at least 1 month at 25°C. A slow and sustained release of 60% of latanoprost was achieved by 14 days in the in vitro release study. The same formulation demonstrated a greater sustained IOP lowering effect compared with daily administration of topical latanoprost beyond 90 days (4.8 ± 1.5 vs 2.5 ± 0.9 mmHg; P < 0.001). No signs of inflammation were evident in the eyes from slit-lamp examination analysis.
  
  
  CONCLUSIONS
  The loading required for a long-term sustained delivery of latanoprost for up to 90 days in the rabbit eyes was achieved with EggPC liposomes. A single injection of latanoprost-loaded EggPC liposomes can lower the IOP for up to 90 days, with a greater IOP lowering effect than daily topical administration of latanoprost.
authors.affiliation: Materials Science and Engineering, Nanyang Technological University, Singapore.
authors.forename: Jayaganesh V
authors.initials: JV
authors.lastname: Natarajan
authors.forename: Marcus
authors.initials: M
authors.lastname: Ang
authors.forename: Anastasia
authors.initials: A
authors.lastname: Darwitan
authors.forename: Sujay
authors.initials: S
authors.lastname: Chattopadhyay
authors.forename: Tina T
authors.initials: TT
authors.lastname: Wong
authors.forename: Subbu S
authors.initials: SS
authors.lastname: Venkatraman
mesh_terms: D060433:Administration, Ophthalmic; D000704:Analysis of Variance; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations; D004355:Drug Stability; D005123:Eye / Q000378:metabolism; D005260:Female; D005901:Glaucoma / Q000188:drug therapy* / Q000378:metabolism; D056965:Injections, Intraocular; D007429:Intraocular Pressure / Q000187:drug effects; D000077338:Latanoprost; D008081:Liposomes / Q000008:administration & dosage / Q000737:chemistry; D050997:Nanomedicine / Q000379:methods*; D010316:Particle Size; D010713:Phosphatidylcholines / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D011817:Rabbits
chemical_list: D000959:Antihypertensive Agents; D003692:Delayed-Action Preparations; D008081:Liposomes; D010713:Phosphatidylcholines; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost