title: Emulsion of Chloramphenicol: an Overwhelming Approach for Ocular Delivery.
abstract: BACKGROUND
  Ophthalmic formulations of chloramphenicol have poor bioavailability of chloramphenicol in the ocular cavity.
  
  
  OBJECTIVE
  The present study aimed at exploring the impact of different oil mixtures in the form of emulsion on the permeability of chloramphenicol after ocular application.
  
  
  METHODS
  Selection of oil mixture and ratio of the components was made by an equilibrium solubility method. An emulsifier was chosen according to its emulsification properties. A constrained simplex centroid design was used for the assessment of the emulsion development. Emulsions were evaluated for physicochemical properties; zone of inhibition, in-vitro diffusion and ex-vivo local accumulation of chloramphenicol. Validation of the design using check-point batch and reduced polynomial equations were also developed. Optimization of the emulsion was developed by software Design® expert 6.0.8. Assessment of the osmolarity, ocular irritation, sterility testing and isotonicity of optimized batch were also made.
  
  
  RESULTS
  Parker Neem®, olive and peppermint oils were selected as an oil phase in the ratio 63.64:20.2:16.16. PEG-400 was selected as an emulsifier according to a pseudo-ternary phase diagram. Constrained simplex-centroid design was applied in the range of 25-39% water, 55-69% PEG-400, 5-19% optimized oil mixture, and 1% chloramphenicol. Unpaired Student's t-test showed for in-vitro and ex-vivo studies that there was a significant difference between the optimized batch of emulsion and Chloramphenicol eye caps (a commercial product) according to both were equally safe.
  
  
  CONCLUSIONS
  The optimized batch of an emulsion of chloramphenicol was found to be as safe as and more effective than Chloramphenicol eye caps.
authors.affiliation: School of Pharmacy, RK University, Rajkot-Bhavnagar highway, Rajkot, Gujarat 360020.
authors.forename: Kalpesh C
authors.initials: KC
authors.lastname: Ashara
authors.affiliation: School of Pharmacy, RK University, Rajkot-Bhavnagar highway, Rajkot, Gujarat 360020.
authors.forename: Ketan V
authors.initials: KV
authors.lastname: Shah
mesh_terms: D060433:Administration, Ophthalmic; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D002701:Chloramphenicol / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004655:Emulsions / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D005123:Eye / Q000378:metabolism*; D005989:Glycerides; D006041:Goats; D036142:Mentha piperita; D000069463:Olive Oil; D009883:Ophthalmic Solutions; D010938:Plant Oils; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D013729:Terpenes
chemical_list: D000900:Anti-Bacterial Agents; D004655:Emulsions; D005989:Glycerides; D000069463:Olive Oil; D009883:Ophthalmic Solutions; D010938:Plant Oils; D013729:Terpenes; D011092:Polyethylene Glycols; C002443:neem oil; D002701:Chloramphenicol; C015424:peppermint oil; C000595213:polyethylene glycol 400
keywords: biphasic system; chloramphenicol; constrained simplexcentroid design; emulsion; ocular accumulation