Begell House Inc.
Critical Reviews™ in Therapeutic Drug Carrier Systems
CRT
0743-4863
24
1
2007
Pharmaceutical Approaches to Preparing Pelletized Dosage Forms Using the Extrusion-Spheronization Process
1-40
10.1615/CritRevTherDrugCarrierSyst.v24.i1.10
Namrata R.
Trivedi
Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 26 South Dunlap Street, Memphis, TN 38163, USA
Maria Gerald
Rajan
Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 26 South Dunlap Street, Memphis, TN 38163, USA
James R.
Johnson
Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 26 South Dunlap Street, Memphis, TN 38163, USA
Atul J.
Shukla
Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 26 South Dunlap Street, Memphis, TN 38163, USA
Pelletized dosage forms date back to the 1950s, when the first product was introduced to the market. Since then, these dosage forms have gained considerable popularity because of their distinct advantages, such as ease of capsule filling because of better flow properties of the spherical pellets; enhancement of drug dissolution; ease of coating; sustained, controlled, or site-specific delivery of the drug from coated pellets; uniform packing; even distribution in the GI tract; and less GI irritation. Pelletized dosage forms can be prepared by a number of techniques, including drug layering on nonpareil sugar or microcrystalline cellulose beads, spray drying, spray congealing, rotogranulation, hot-melt extrusion, and spheronization of low melting materials or extrusion-spheronization of a wet mass. This review discusses recent developments in the pharmaceutical approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process over the last decade. The review is divided into three parts: the first part discusses the extrusion-spheronization process, the second part discusses the effect of varying formulation and process parameters on the properties of the pellets, and the last part discusses the different approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process.
Lipid-Based Cochleates: A Promising Formulation Platform for Oral and Parenteral Delivery of Therapeutic Agents
41-62
10.1615/CritRevTherDrugCarrierSyst.v24.i1.20
Ravi
Rao
College of Pharmacy and Allied Health Professions, St. John's University, Queens, NY 11439
Emilio
Squillante, III
College of Pharmacy and Allied Health Professions, St. John's University, Queens, NY 11439, USA
Kwon H.
Kim
College of Pharmacy and Allied Health Professions, St. John's University, Queens, NY 11439
Cochleates are lipid-based supramolecular assemblies that display great potential as delivery systems for systemic delivery of drugs, including peptides, proteins, vaccines, oligonucleotides, and genes. This is mainly attributed to their high stability and biocompatibility and their ability to deliver both hydrophilic and lipophilic drugs. Cochleates have a unique multilayered spiral structure, which is composed of a negatively charged phospholipid and a divalent cation, and can encapsulate diverse drug molecules of various shapes and sizes while minimizing toxicity associated with polymeric materials present in micro- and nanoparticle systems. This review describes current technological advances in the preparation methods, physicochemical characterization, and potential applications of cochleates as a drug delivery system for systemic delivery of various types of therapeutic agents.
Oral Colon-Specific Drug Delivery of Protein and Peptide Drugs
63-92
10.1615/CritRevTherDrugCarrierSyst.v24.i1.30
Vivek Ranjan
Sinha
University Institute of Pharmaceutical Sciences, UGC Centre for Advanced Studies, Panjab
University, Chandigarh, India, 160014
Asmita
Singh
University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
Ruchita V.
Kumar
University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
Sanjay
Singh
Department of Pharmaceutics, IT, BHU, Varanasi, India
Rachana
Kumria
Ind-Swift Ltd. Parwanoo, 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
With the advent of new technologies and radical growth in the field of biotechnology, dozens of protein and peptide drugs have been marketed. However, there are several challenges for successful delivery of such molecules. A number of routes have been used for the delivery of these fragile molecules by exploring various novel delivery technologies, including microspheres, liposomes, gel spheres, nano-spheres, niosomes, microemulsions, use of permeation enhancers, use of protease inhibitors, etc. But the route that has attracted the attention of worldwide drug delivery scientists is the oral route due to its various advantages. Even though the proteolytic activity is higher in a few segments of the gastrointestinal tract (GIT), this route has certain segments that have lower proteolytic activity, for example, the colon. The colon has captured attention as a site for the delivery of these molecules because of its greater responsiveness to absorption enhancers, protease inhibitors, and novel bioadhesive and biodegradable polymers. Although the success rate of these approaches, when used alone is pretty low, when used in combinations, these agents have demonstrated wonders in increasing the drug bioavailability. This review focuses on the challenges, pharmaceutical concepts, and approaches involved in the delivery of these fragile molecules, specifically to the colon. This review also includes studies conducted on colonic targeting of such drugs. Further studies may lead to improvements in therapy using protein/peptide drugs and refinements in the technology of colon-specific drug delivery.