title: Impact of administration angle on the cost of artificial tear solutions: does bottle positioning minimize wastage?
abstract: OBJECTIVE
  The aim of this study was to describe the cost considerations of multidose artificial tear products according to drop volume and the number of usable drops per bottle, based on a 45- versus 90-degree administration angle.
  
  
  METHODS
  Densitometric assessment of the drop volume of five multidose artificial tear products of a 15-mL labeled bottle size in conjunction with predictive cost analysis.
  
  
  RESULTS
  The correlation between drop volume and density was not significant (Spearman correlation, P = 0.4500; alpha < 0.05). Overall, drop size ranged from 65.9 microL to a nadir of 30.8 microL, with a statistically significant difference (Student t test, P < 0.05) between 45- and 90-degree volumes for all but one product. Cost analysis demonstrated up to a $1.93 per bottle cost savings by the administration of drops at a 45- rather than a 90-degree bottle angle.
  
  
  CONCLUSIONS
  Products that provide a higher number of drops per dollar of product offer economic advantages that may not be otherwise discernible by the examination of the product retail price alone. Furthermore, it is shown that altering the angle of administration may, in general, result in significant economic ramifications in the use of multidose artificial tear products longitudinally.
authors: Department of Ophthalmology, Rush University College of Medicine, Chicago, IL 60612, USA. bgaynes@rush.edu
authors: Bruce I
authors: BI
authors: Gaynes
authors: Ramesh M
authors: RM
authors: Singa
authors: Gabriel
authors: G
authors: Schaab
authors: Yevgeniva
authors: Y
authors: Sorokin
mesh_terms: D000287:Administration, Topical; D003365:Costs and Cost Analysis; D003720:Densitometry; D016527:Drug Costs; D004349:Drug Packaging / Q000191:economics*; D015352:Dry Eye Syndromes / Q000188:drug therapy; D006801:Humans; D004366:Nonprescription Drugs / Q000008:administration & dosage / Q000191:economics*; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000191:economics*
chemical_list: D004366:Nonprescription Drugs; D009883:Ophthalmic Solutions