RESUMO
Objective: To study the correlation between the empty bottle volume, negative pressure and gas production of the freeze-dried powder in the out-patient pharmacy intravenous admixture center of a children' s hospital in order to provide reference for the drug production. Methods:20 ml Syringes were used to measure the volume of empty bottles, negative pressure and produced gas. The relationship between the theoretical drug dissolution volume and the actual dissolution volume was compared, and the precautions for the drug production were put forward. Results:Among the tested 30 drugs, 6 ones were with the actual dissolution volume half of the theoretical dissolution volume, 8 ones were with negative pressure in the bottles, and 3 ones were with produced gas after dissol-ving. It was appropriate that the empty bottle volume be 4 ml larger than the theoretical dissolution volume, and it was appropriate that the negative pressure volume of drugs was slightly larger than the theoretical dissolution volume. Negative pressure should be still kept in the bottles after the gas production. Conclusion:The design of part of freeze-dried powder injection needle shows defects resulting in drug mixing difficulties to a certain extent.