title: Ointment is evenly spread on the skin, in contrast to creams and solutions.
abstract: BACKGROUND
  The efficacy of topical therapy depends on the patient spreading the topical drug in an even layer to give a standard dose. Ointments are believed to be more effective than creams and solutions.
  
  
  OBJECTIVE
  To compare the application and spreading of four different pharmaceutical vehicles.
  
  
  METHODS
  Twenty-nine healthy volunteers applied a fixed amount (0.1 g) of solution (S), ointment (O), cream (C) and low-viscosity cream (LVC) to the abdominal skin. Area of spread, skin surface lipids (dependent on formulation) and changes in skin surface temperature (cooling due to evaporation of formulation water/alcohol) were measured.
  
  
  RESULTS
  Area of spread: O = C = LVC = S. Skin surface lipids: O > C > LVC > S. Difference in skin surface lipids between centre and periphery: O < C = LVC = S. Cooling: O < C = LVC < S.
  
  
  CONCLUSIONS
  The four formulations were spread to similar areas. The ointment was spread evenly in the treated area while the other formulations were unevenly spread, with a lower dose in the periphery. Creams and solutions have disadvantages as vehicles, as rapid evaporation of formulation water/alcohol, measured as cooling, influences spread, resulting in an uneven topical dose within the treated area. In contrast, ointment is evenly spread and is thus a more appropriate formulation. Patients should be instructed to apply creams and solutions to multiple sites and to spread them quickly.
authors.affiliation: Dermatological Research Department, Leo Pharmaceutical Products, DK-2750 Ballerup, Denmark.
authors.forename: U I
authors.initials: UI
authors.lastname: Ivens
authors.forename: B
authors.initials: B
authors.lastname: Steinkjer
authors.forename: J
authors.initials: J
authors.lastname: Serup
authors.forename: V
authors.initials: V
authors.lastname: Tetens
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000704:Analysis of Variance; D001831:Body Temperature / Q000187:drug effects; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009824:Ointments / Q000008:administration & dosage*; D010349:Patient Compliance; D019999:Pharmaceutical Solutions / Q000008:administration & dosage*; D011446:Prospective Studies
chemical_list: D009824:Ointments; D019999:Pharmaceutical Solutions