VARIABLES INFLUENCING DRUG RELEASE PATTERN OF MICROSPHERES: A TECHNICAL REVIEW

Purpose of writing this review on microspheres was to compile the recent literature with special focus on the various variables which affect the drug release pattern of microspheres. There are various approaches in delivering a therapeutic substance to the target site in a controlled release fashion. One such approach is using microspheres as a carrier for drugs. For success of microspheres as drug delivery system, it’s necessary they release the drug in controlled release manner for longer duration. This can be made possible by optimizing the formulation as well as process variables. Therefore before designing the microspheres formulation, it’s necessary to understand the effect of various variables on the drug release pattern of these microspheres. The intent of the paper is providing the deep understanding of various variables those are useful during the development of microspheres system. This paper also summarize the various relevant aspects of microsphere

SELF-MICRO EMULSIFYING DRUG DELIVERY SYSTEMS (SMEDDS): A REVIEW ON PHYSICO-CHEMICAL AND BIOPHARMACEUTICAL ASPECTS

Nearly 40% of new drug candidates exhibit low solubility in water, which is a challenge in development of optimum oral solid dosage form in terms of formulation design and bioavailability of new pharmaceutical products. Many strategies have been used to overcome these problems either by means of modifying the solubility or maintaining the drug in dissolved form throughout gastric transit time. Much attention has focused on lipid solutions, emulsions and emulsion pre-concentrates, which can be prepared as physically stable formulations suitable for encapsulation of such poorly soluble drugs. Recently, self-micro emulsifying drug delivery systems (SMEDDS) especially have attracted increasing interest primarily because  these are physically stable, easy to manufacture, can be filled in soft gelatin capsules and then will generate a drug containing micro-emulsion with a large surface area upon dispersion in the gastrointestinal tract. The emulsions will further facilitate the absorption of the drug due via intestinal lymphatic pathway and by partitioning of drug into the aqueous phase of intestinal fluids. In the present review, an overview of SMEDDS as a key technology for formulating lipophilic drugs and various factors that potentially affect the oral bioavailability of such drugs are presented. Keywords: Low solubility, Oral bioavailability, Self-micro emulsion, Intestinal lymphatic pathway.Â

Outer membrane protein folding from an energy landscape perspective

The cell envelope is essential for the survival of Gram-negative bacteria. This specialised membrane is densely packed with outer membrane proteins (OMPs), which perform a variety of functions. How OMPs fold into this crowded environment remains an open question. Here, we review current knowledge about OFMP folding mechanisms in vitro and discuss how the need to fold to a stable native state has shaped their folding energy landscapes. We also highlight the role of chaperones and the β-barrel assembly machinery (BAM) in assisting OMP folding in vivo and discuss proposed mechanisms by which this fascinating machinery may catalyse OMP folding