Cardiopulmonary side-effects and pharmacokinetics of an emulsion of propofol (Disoprivan (R)) in comparison to propofol solved in polysorbate 80 in goats

The aim of this study was to determine whether any pharmacokinetic or pharm acodynamic differences exist in goats between propofol in its currently lic ensed form (Disoprivan(R)) and a new 1% solution of propofol (NSP) containi ng polysorbate 80. Nine goats received, on two different occasions in a ran domized double-blinded order, 4 mg/kg propofol intravenously (i.v.; Disopri van(R) or NSP). To detect differences in cardiopulmonary effects and pharma cokinetics, the Wilcoxon signed rank test for paired data was used. In the NSP group the duration of initial apnoea was significantly longer, and 6 an d 12 min after drug application p(A)O(2) levels were significantly lower th an in the Disoprivan(R) group. Mean cardiovascular parameters did not diffe r significantly between the groups but in the NSP group in six goats marked changes in blood pressure occurred: systolic arterial pressures fell to a minimum of 40-60 mmHg within the first 10 min. This was followed by a marke d increase in blood pressure,with maxima exceeding 300 mmHg. In the NSP gro up the half-life of propofol was significantly longer, the clearance rate w as smaller and the areas under the drug concentration-time curves were larg er than in the Disoprivan(R) group. The cardiopulmonary side-effects of NSP suggest that propofol dissolved in polysorbate 80 is not a suitable altern ative to the current formulation of propofol.