Introduction: Uses of methotrexate (MTX) are well established for the treatment of various types of malignancy, psoriasis, rheumatological diseases and the medical termination of pregnancy. Formulation and targeting approaches for MTX with controlled release carriers, multiparticulate systems, prodrug and drug conjugates have been found to improve bioavailability, reduce adverse effects and maximize clinical efficacy, compared with conventional methods. Areas covered: This exhaustive literature survey on different electronic databases covers drug delivery and clinical trials on MTX. This review deals with the challenges and achievements of controlled release, multiparticulate, prodrug and drug conjugate systems of MTX. Expert opinion: Therapeutic drug monitoring of MTX is crucial to attain a good efficacy. In spite of the advantages of multiparticulate, prodrug and drug conjugates, clinical applications of such formulations of MTX are still under infancy. These drug delivery systems require the special at...

It is advantageous to deliver some drugs with short half-life, and which are to be given frequently for chronic ailments, in the form of controlled-release (CR) formulations. The orally administered drugs, in the form of conventional matrix or reservoir type formulations, pose problems of bioavailability fluctuations due to gastric pH variations. Moreover, the release of drug(s) from these systems is affected by the hydrodynamic conditions of the body. Osmotically controlled drug delivery systems utilize the principles of osmotic pressure for the controlled delivery of active agent(s). The release rate of drug(s) from these systems is independent of the physiological factors of the gastrointestinal (GI) tract to a large extent. In the present review, theory underlying the delivery of drugs from osmotic systems is presented. Different types of oral osmotic systems, their advantages over conventional matrix and reservoir types of systems, and their applications are also discussed. Finally, some of the limit...