Peroral glipizide and gabapentin causes bioavailability fluctuations due to erratic absorption, which result in unpredictable pharmacological actions. Recent advances in drug delivery have led to search for routes of drug administration that could deliver these drugs to systemic circulation without compromising efficacy or posing any threats to the patient. Transdermal route is known to by-pass these challenges encountered in traditional drug administration procedures like hepatic first pass metabolism, gastrointestinal disturbances, low absorption, high frequency of administration and poor compliance. This alternative route requires careful selection of vehicles that can circumvent barrier properties of the SC. Microemulsion and co-solvents are known to possess these qualities.This book, therefore, provides insights into the manipulation of co-solvents and coconut oil-based microemulsions for efficient delivery and sustainable systemic circulation of gabapentin and glipizide. Inall, the prospect of further development is high and this provides drug delivery scientists, endocrinologists, neurologists and dermatologists towards management of Type-2 diabetes and bipolar disorders.