Background: Conventional oral dosage forms have limited bioavailability and frequent dosing of the drug is needed to maintain the effective therapeutic concentration in the body. This results in poor patient compliance and fluctuations in the plasma drug levels, especially in the chronic diseases and disorders.
Objective: To overcome such problems and to enhance the efficiency and bioavailability of the drug, modified drug delivery systems such as extended release delivery systems (controlled release; sustained release) and delayed release delivery systems are developed which can prolong the release and hence action of the drug in the body.
Methods: Through this review, we throw the light on recent patents and patent applications on modified release systems pertaining to oral dosage forms. The various free patent search databases were used to collect and analyze the information on modified release delivery systems.
Results: Modified release systems such as extended release and delayed release delivery systems have been found to be of great significance due to their advantages over immediate release dosage forms. These systems are formulated using various approaches, different types of release controlling polymers such as natural, semisynthetic and synthetic polymers and found to avoid the limitations of conventional oral dosage forms.
Conclusion: Modified drug release systems have potential especially, in case of the chronic diseases, mental health disorders and lifestyle diseases and disorders. These systems have unique commercial advantages which will sustain the interest of both the researchers and the pharmaceutical companies.
Keywords: Modified release systems, extended release systems, controlled release systems, sustained release systems, delayed release systems, oral dosage forms, multilayer dosage form, multilayered tablets
In-Depth Study into Polymeric Materials in Low-Density Gastroretentive Formulations
