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Brookfield AMETEK

Medicine: Cough Suppressant/Expectorant

Laboratory Viscometer Application Data Sheet

USE

To relieve coughs and chest congestion.

METHOD 1

Test Equipment:

  • Spring Torque Range: RV
  • Spindle: Enhanced UL Adapter; ULA-EY
  • Accessories: TC-502 Programmable Bath
  • Speed, rpm: 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160 and 170 rpm.
  • Temperature: 22C

* While a particular model/version may be used as an example in this method, any current or past model/version from the same series may also be used. Please consult a sales associate to discuss the most current instrumentation and software available.

We used a Brookfield RVDV-III+ Rheometer, with Rheocalc v3.1 software for automated instrument control and data acquisition. The temperature was regulated using an ULA-EY water jacket connected to a TC-502P Refrigerated Programmable Bath. We ran three trials to determine repeatability. A syringe was used to measure and dispense 16 mL of the substance into the sample chamber. The spindle and chamber were cleaned before each trial, and fresh material was used in each trial. We equilibrated the sample, spindle and chamber for at least three minutes prior to testing. We ran our test in a speed ramp fashion. Using traditional RV speeds like 50 and 100 rpm can make a sufficient test for this type of material. However, since we used a DV-III+ Rheometer we had the capability of running the test at a wide variety of speeds. Representative data from the analyses are shown in Figure 1, below:


Figure 1: Cough Suppressants A and B, at 22C.

Figure 1 illustrates that both Brand A and Brand B are essentially Newtonian fluids. Newtonian fluids are characterized by a constant viscosity, independent of shear rate. Slight differences in viscosity over our range of shear rates can be accounted for by the 1% tolerance of the instrument. Figure 1 also shows that Brand A is more viscous than Brand B.

METHOD 2

Test Equipment:

  • Spring Torque Range: LV
  • Spindle: Enhanced UL Adapter; ULA-EY
  • Accessories: TC-502 Programmable Bath
  • Speed, rpm: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15 rpm.
  • Temperature: 22C

* While a particular model/version may be used as an example in this method, any current or past model/version from the same series may also be used. Please consult a sales associate to discuss the most current instrumentation and software available.

We used a Brookfield LVDV-III+ Rheometer, with Rheocalc v3.1 software for automated instrument control and data acquisition. The temperature was regulated using an ULA-EY water jacket connected to a TC-502P Refrigerated Programmable Bath. We ran three trials to determine repeatability. A syringe was used to measure and dispense 16 mL of the substance into the sample chamber. The spindle and chamber were cleaned before each trial, and fresh material was used in each trial. We equilibrated the sample, spindle and chamber for at least three minutes prior to testing. We ran our test in a speed ramp fashion. Using Traditional LV speeds like 3, 6 and 12 rpm can make a sufficient test for this type of material. However, since we used a DV-III+ Rheometer we had the capability of running the test at a wide variety of speeds. Representative data from the analyses are shown in Figure 2, below:


Figure 2: Cough Suppressants A and B, at 22C.

Figure 2 illustrates that both Brand A and Brand B are essentially Newtonian fluids. Newtonian fluids are characterized by a constant viscosity, independent of shear rate. Slight differences in viscosity over our range of shear rates can be accounted for by the 1% tolerance of the instument. Figure 2 also shows that Brand A is more viscous than Brand B.