This thesis encompasses three significant projects. The study includes the characterization and evaluation of the properties of a commercial contraceptive transdermal patch, Ortho Evra® by Dielectric Analysis and Differential Scanning Calorimetry (DSC). This study helps in monitoring the mobility of the drug and transport properties by Isothermal and Scanning Dielectric Analysis as a function of temperature and frequency. The drugs in this product are norelgestromin and ethinyl estradiol. DSC was used to detect any crystalline character of the drugs by their fusion properties. Having no melting endotherm and detecting a glass transition temperature suggested that the drugs in the patches were amorphous. The amorphous form of the drug has more bioavailability. The isothermal DEA a plot of Log frequency vs. reciprocal temperature (K) revealed two critical modulating frequencies at body temperature 37°C for the two API drugs with DEA peak frequencies at 460 and 560 Hz.
The main project includes studying the polarization of macro and micro molecular liquid drugs by Dielectric Analysis, B-Cell (a customized isothermal dielectric device) and Differential Scanning Calorimetry. This study demonstrated in vitro transport of selected non-ionic high (e.g. insulin) and low (e.g. Diphenhydramine) molecular weight drugs through excised biological tissue membranes using alternating current (AC) electrokinetics. This new technique of the drug delivery system enhances benefits over systemic oral therapies, in which clinically sufficient quantities of the active ingredient do not reach the intended target organ and/or use of the drugs result in serious side effects. An optimally-tuned low-voltage applied AC electrical field has been found capable of inducing polarization and delivering micro and macromolecules through a biological membrane. The relationships between factors such as delivery time, AC voltage amplitude and frequency, and transported drug concentration were investigated. A factorial design was used to establish experimental parameters for the insulin solution evaluating DEA variables of voltage, frequency, time, temperature, drug dose, and membrane thickness. A clear result of the experimental design for insulin was that the low frequency was significant in enhanced drug delivery. Dielectric Analysis was used to modulate the drugs delivery response measured by a change in the log conductivity vs. log frequency curve at a lower frequency of 500 Hz and a higher frequency of 1000 Hz for insulin at 37°C. Imposition of a low frequency of 500 Hz aliened dipoles and higher frequency aided the mobility of the drug ions into the biomembranes. The delivery was confirmed qualitatively and quantitatively by enhanced conductivity for the drugs based on the “polaron theory” of conductivity or the “hopping model” and UV spectroscopy.
The third project includes a study to develop a standard protocol to determine the water content and type by thermal analysis of Milk of Magnesia. Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA) were used in a novel manner for examining the commercial pharmaceutical suspensions and to note the difference between the brand and the generic forms.