Thesis
Studies of a lyophilised nasal delivery system
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2000
- Thesis identifier
- T9921
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- The in vitro and in vivo drug release characteristics and physico-mechanical properties of a putative lyophilised nasal dosage form, prepared using hydroxypropyl methylcellulose (HPMC), as a hydrophilic gel forming excipient have been investigated. The in vitro release of model compounds (nicotine and UK-92, 480) was studied in a diffusion cell, which, with a minimum dissolution volume on the donor side, was intended to mimic the low hydration environment of the nasal mucosa. In vitro drug release rate decreased with the concentration of HPMC used, whether the donor side of the cell was presented with a solution, powder or lyophilised plug of the drug - excipient mixture. However at any particular HPMC concentration, drug (nicotine) release rate was faster from solution than from lyophilised plug. The difference in release rate between solution and lyophilisate was greater at high polymer concentrations and indicated that the high viscosity solution that resulted from hydration of the lyophilised plug in the diffusion cell was responsible for the difference. However, release (nicotine) rate was found to be relatively independent of HPMC molecular weight. The bioavailability of nicotine from lyophilised plug after absorption from the sheep nasal cavity was found to be higher than from other intranasally administered dosage forms such as powder and solution. The mechanical properties of hardness, fracturability, springiness and resilience of the (HPMC) plugs and adhesivity of hydrated plugs, which are important parameters for handling, insertion and residence time on the nasal mucosal surface, were studied using a Texture Analyser. These parameters could be manipulated by changing the concentration of individual formulation components. For lyophilisates in the weight range 5-40 mg, the quantity of water required for complete hydration, which occurred in about 15 sec, lay in the range 50-120 pl. A manufacturing process for the production of lyophilised nasal inserts is also described.
- Advisor / supervisor
- Stevens, Howard N.E.
- Baillie, Alan J.
- Resource Type
- DOI
- Funder
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