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Title: Creep modelling and rheological studies on surfactant based stimulus responsive drug delivery platforms
Author: Yu , Tao
Awarding Body: Queen's University Belfast
Current Institution: Queen's University Belfast
Date of Award: 2013
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This thesis has introduced the construction and early development of a mathematical creep model for the assessment of retention of gels for vaginal applications. The creep model can provide important information in terms of the potential retained periods in vivo for a gel formulation, and hence evaluating the success or failure of the platform design. It was found that the use of creep model was independent upon the type of materials, shear stress, temperature, dilution, or the incorporation of drugs. The retention of platforms for vaginal, nasal, periodontal administrations may be evaluated using creep model. Moreover, the applied shear stress was found to have overcome the restriction of the Linear Viscoelastic Region. It should be emphasized here again that the creep model is the first model ever in the literature that offers possibility to mathematically measure the retention of a gel formulation. The characterizations of non-ionic surfactant based systems (Tetronic304, Tween80, Brij30, TritonXIOO and Procetyl) for vaginal applicat ions were conducted following the introduction of the creep model . The combinations consisting of non-ionic surfactants and mucoadhesive polymers showed moisture responsive properties. The low viscosity in the absence of moisture may offer advantages in administration and spreading of formulations. The subsequent gelling in situ in the presence of moisture may provide prolonged retention for sustained drug delivery. The effects of surfactant, mucoadhesive polymer, drug loading, dilution, and shear stress on rheological properties, especially on retention were examined. Another-moisture responsive formulation known to possess the Lyotropic Liquid Crystals structure, and composed ofTetronic904, Procetyl and Artificial Saliva was then designed for the Tetracycline Hel release within the periodontal pocket. The results showed that the liquid isotropic phase and lamellar phase were responsible for easy administration and the hexagonal and cubic phase were appropriate to provide sustained release profile.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available