| Summary: | Inkjet printing is a technology that is witnessing many applications across numerous areas of research. This technology is adopted here to address some challenges in medicine and pharmaceutical science. A thermal inkjet (HP 5940) was modified and used for this work; the robustness of the modified printer was confirmed afterwards. With printing of bacteria as a theme in this thesis, an initial assessment of the effect of ink jetting on the viability of bacterial cells was conducted and the damage was found to be negligible. An analytical application of ink jetting in antimicrobial susceptibility testing was conducted. A model was developed whereby varying antibiotic concentrations were printed onto agar-coated glass slides; a fixed bacterial population was then printed onto the varying antibiotic concentrations. The concentration of printed antibiotic exhibiting no bacterial growth after incubation was then computed based on an initial cartridge characterisation using HPLC. Minimum inhibitory concentrations obtained for antibiotics tested, using the designed model, when compared with standard broth microdilution technique were within an acceptable range, i.e., one doubling dilution apart. The inkjet printing technology was also applied in formulating probiotics. Probiotics for site-specific delivery into the lower small intestines or colon were formulated by printing the probiotic strain (Lactobacillus acidophilus LA 5) onto edible starch paper and encapsulating organisms in PhloralÒ pre-coated capsules to protect organisms from the harshness of stomach fluids. The encapsulated formulation exhibited over 40% recovery at sites of interest with 78.3% of the administered strain adhering to intestinal cells. The formulation was able to eliminate completely a population of E. coli when co-incubated. The potential of ink jetting in formulating probiotic oro-dispersible films (ODFs) was also explored. ODFs containing Streptococcus salivarius and xylitol were prepared and the benefits in managing dental caries were assessed. The probiotic ODFs reduced Streptococcus mutans numbers by 2.86 log cycles.
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