Microbubbles are micron-sized contrast-increasing agents for diagnostic ultrasound imaging. At half of the excitation frequency due to nonlinear oscillations, they generate a subharmonic response, the magnitude of which changes by the ambient pressure. Subharmonic Aided Pressure Estimation (SHAPE) is a noninvasive method to measure local in vivo pressure utilizing subharmonic emission from microbubbles using medical ultrasound. In this study, we investigated the in vitro dosage effect of Sonazoid, a commercially available microbubble, on SHAPE. We subjected Sonazoid microbubbles to acoustic excitations ranging from 100 to 700 kPa peak negative pressure (PNP) and at a frequency of 3 MHz. We increased the ambient pressure up to 20 kPa and investigated the change in subharmonic signal during eight pressurizing-depressurizing cycles. We observed two different behaviors of subharmonic responses over investigated parameters. Subharmonic response increased significantly with increasing ambient pressure under low PNP excitations for sufficiently high concentrations. Meanwhile, increased ambient pressure at higher PNPs drastically reduced the subharmonic response for sufficiently low concentrations. Reported findings are crucial for characterizing the SHAPE performance of Sonazoid microbubbles, offering valuable insights for improved, consistent, and cost-efficient practice.