Acknowledgements

I would like to express my sincere and deepest gratitude to my advisor, Dr.William F Elmquist for his guidance, patience, enthusiasm, encouragement and invaluable help throughout the graduate studies. His deep vision, broad knowledge and perpetual passion for science always inspired me and have been of great value for me. The past five years have been an invaluable experience in my life. I feel blessed to have Dr.Elmquist as my advisor and I am grateful to him in every possible way. I would like to express my sincere appreciation to Dr.Ronald Sawchuk, Dr. Jayanth Panyam, Dr.Tim Tracy and Dr.Richard Brundage for graciously serving on my oral and thesis committee. Their insightful comments and suggestions have provided a good basis for the present thesis. I thank my fellow labmates, Guoyu Pan, Naveed Shaik, Nagdeep Giri, Ying Chen, Sagar Agarwal, Tianli Wang and Ramola Sane, for all of the intellectual discussions, collaborations, and wonderful times we spent together. I am lucky to be part of this harmonious family and I will truly miss them. I would like to express my gratitude to all the faculty, staff members and students in the Department of Pharmaceutics for th