Trials to Improve Bioavailability of a Drug or certain Drugs

General IntroductionDrug delivery systems are used for maximizing therapeutic index of the drug and also for reduction in the side effects. Oral route remains the prefer route for the administration of therapeutic agents because low cost of therapy and ease of administration leads to higher level of patient compliance (Navneet et al.‚ 2010; Gopalakrishnan and Chenthilnathan, 2011). Approximately 50% of the drug delivery systems available in the market are oral drug delivery system (Shivkumar et al. ‚ 2004). The oral route is considered as the most promising route of the drug delivery and effective oral drug delivery may depend upon many factor such as gastric emptying process, gastrointestinal transit time of the dosage form, drug release from the dosage form and site of absorption of drug. The high level of patient compliance has been observed in taking oral dosage forms is due to the ease of administration and handling of these forms. Although a lot of advancements have been seen in oral controlled drug delivery system in the last few decades, this system has been of limited success in case of drugs with a poor absorption window throughout the GIT. To modify the GI transit time is one of the main challenge in the development of oral controlled drug delivery system.Drugs having short half-life are eliminated quickly from the blood circulation. Various oral controlled delivery systems have been designed which can overcome the problems of unpredictable gastric emptying. This has led to the development of oral gastro retentive floating dosage forms.