ABSTRACT
Objective: To optimize the mixing technology of Daphnes Giraldii Cortex gel plaster (DGCGP) by using rheological parameters elastic modulus (G'), viscous modulus (G″), yield stress (τ0), creep compliance [J(t)] and loss coefficient (tanδ) as evaluation indexes. Methods: Using orthogonal design, L9(34) orthogonal design was used to screen out the best mixing technology of DGCGP and predict the suitable coating conditions by taking the temperature, rotating speed and mixing time of the mixed materials as influencing factors and the rheological parameters of the medicated compound as evaluating indexes. Results: The optimum DGCGP mixing process was as following: 70℃ at 10 r/min for 2 h. Under this condition, the viscoelasticity, temperature and shear resistance, deformation resistance and stability of the mixture were all good. Conclusion: DGCGP prepared by this optimized process had good appearance, soft texture, good adhesion with skin, good viscoelasticity and better quality.
ABSTRACT
Objective: To provide scientific basis for the temperature condition of Daphnes Giraldii Cortex (DGC) post-cross-linked gel plaster during storage and transportation. Methods: Taking linear viscoelastic region, modulus, yield stress, phase angle, composite viscosity and creep compliance as evaluation indexes, amplitude scanning, frequency scanning, temperature scanning and creep testing were carried out on the cross-linked gel plaster matrix after DGC by an advanced rotary rheometer, and relevant data of elastic modulus, viscosity modulus, phase angle, composite viscosity, creep compliance and yield stress of the samples which were stored at room temperature, -20 ℃ and -50 ℃ for 1, 3, 8, and 13 d were respectively obtained. Results: All samples of DGC post-crosslinking gel plaster showed elastic characteristics and stable state. After storage under different conditions, the state is still stable and the dispersibility is better. The peel strength of samples stored for 8 d and 13 d was decreased. The retention of samples stored at -50 ℃ for 13 d was decreased. Conclusion: DGC plaster containing post-crosslinked gel matrix had stable state, good dispersibility, initial adhesion, peel strength and shape retention when samples were stored below 0 ℃ for 3 d.
ABSTRACT
As a new technique of determining the viscoelasticity of soft biomaterials and cell cytoplasm in living cells, particle tracking microrheology (PTM) is mainly applied in the biomechanical research field, such as cell movement, embryo development, laminopathies. PTM has many advantages over the conventional detection methods in cell mechanics. Using this technique, the Brownian motion of probe particles embedded in the medium could be measured by the video-microscopy, and the movement trajectories of the probe could be mathematically transformed into the mean squared displacements (MSDs) thus to extract the parameters such as the frequency-dependent viscoelastic modulus or the creep compliance from the time dependent MSDs of the probes. The basic principles of PTM technique and its application in biomechanics will be reviewed in this paper.