Begell House Inc.
Critical Reviews™ in Therapeutic Drug Carrier Systems
CRT
0743-4863
20
6
2003
Remote Controlled Capsules in Human Drug Absorption (HDA) Studies
26
10.1615/CritRevTherDrugCarrierSyst.v20.i6.10
Ian R.
Wilding
Pharmaceutical Profiles Ltd., Ruddington Fields, Ruddington, Nottingham, UK, NG11 6JS
David V.
Prior
Pharmaceutical Profiles Ltd., Ruddington Fields, Ruddington, Nottingham, UK
The biopharmaceutical complexity of today's new drug candidates provides significant challenges for pharmaceutical scientists in terms of both candidate selection and optimizing subsequent development strategy. In addition, life cycle management of marketed drugs has become an important income stream for pharmaceutical companies, but the selection of least risk/highest benefit strategies is far from simple. The proactive adoption of human drug absorption (HDA) studies using remote controlled capsules offers the pharmaceutical scientist significant guidance for planning a route through the maze of product development. This review examines the position of HDA studies in drug development, using a variety of case histories and an insightful update on remote controlled capsules to achieve site-specific delivery.
Diagnostic Microspheres: An Overview
28
10.1615/CritRevTherDrugCarrierSyst.v20.i6.20
Vivek Ranjan
Sinha
University Institute of Pharmaceutical Sciences, UGC Centre for Advanced Studies, Panjab
University, Chandigarh, India, 160014
V.
Goyal
University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
J. R.
Bhinge
University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh; and Center with Potential for Excellence in Biomedical Sciences, Panjab University, Chandigarh, India
B. R.
Mittal
Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
A.
Trehan
Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
Diagnostic methods have become increasingly complex and frequently involve the use of agents that must meet the same approval criteria as drugs. The search for diagnostic contrast agents has spread from X-ray to other imaging modalities, especially to magnetic resonance imaging (MRI) and ultrasound. A wide variety of methods have been used to develop microencapsulated agents, from liposomal entrapment to use of biodegradable polymers. Various scientific and technological advancements have been made in the research and development of diagnostic microspheres. Diagnostic microspheres can be used to understand the human body functions in both healthy and sick people. For example, they allow the detection of malignancies vs. benign tissue changes. Diagnostic microspheres give useful clinical information for various diseases, are very stable, and have proven efficacy in the quantitative measurement of blood flow to an organ. This review discusses various aspects of diagnostic microspheres, such as the choice of contrast agents and radioactive molecules, and their applications in blood flow measurements and organ imaging.
Gastric Retentive Dosage Forms: A Review
28
10.1615/CritRevTherDrugCarrierSyst.v20.i6.30
Sui Yuen Eddie
Hou
Depomed, Inc., Menlo Park, California, USA
Verne E.
Cowles
Depomed, Inc., Menlo Park, California, USA
Bret
Berner
Depomed, Inc., Menlo Park, California, USA
Gastric retentive dosage forms have been investigated to provide controlled release therapy for drugs with reduced absorption in the lower gastrointestinal (GI) tract or for local treatment of diseases of the stomach or upper GI tract. Gastric retentive dosage forms rely on either natural GI physiology, such as floating or large tablets that depend on delayed emptying from the fed stomach, or those dosage forms that are designed to fight the physiology and avoid emptying in the fasted state through dosage forms of even larger sizes with or without flotation or bioadhesion. To understand the behavior of the dosage forms, an introduction to GI motility and its measurement is provided. Because the fed mode underlies the successful development of dosage forms that rely on size or flotation, the emptying of these dosage forms in the fed mode and identification of the key factors influencing the variability of gastric retention are discussed. The design and limitations of size or density-based fed mode, and mucoadhesive and expandable fasting-state gastric retentive systems are presented.
Volume 20 Indices
4
10.1615/CritRevTherDrugCarrierSyst.v20.i6.40