Comparação do volume da gota e custo do tratamento dos genéricos de maleato de timolol 0,5%

Drop volume of artificial tear solutions: pharmacoeconomic study

“…The densitometry method for determining the volume was used to determine the volume of the drop (3)(4)(5)(6) . We used the analytical scale Ohaus® Adventurer Pro AV264P (precision of 0.0001 and capacity of 240 g) with certificate of calibration, Laborglas® volumetric pipette of 1.0 mL and Laborglas® watch glass to determine the mass of the liquids.…”

“…Each vial of eyedrops was lightly pressed until a drop fell off from a height of 5.0 cm from the watch glass used on the scale, and the process was repeated until the cumulative total of 10 drops studied was reached. For proper tilt, a protractor was used as a guide in a reference plane, and in relation to the vial base (3,6) .…”

“…Later, the mass of 1.0 ml of each eyedrop was measured with a volumetric pipette. This way, the average volume of each droplet was determined by the ratio between the mass of 1.0 ml and the weight of 10 drops of each eyedrop (volume-to-weight ratio) (3,6) .…”

“…Te average number of droplets contained in each vial was also determined, taking into account the average volume of each drop and the total volume of the vial as advertised by the manufacturer on the product label (3)(4)(5)(6) .…”