Solid lipid nanoparticles are at the forefront of the rapidly developing field of nanotechnology with several potential applications in drug delivery, clinical medicine and research, as well as in other varied sciences. Due to their unique size-dependent properties, lipid nanoparticles offer the possibility to develop new therapeutics. The ability to incorporate drugs into nanocarriers offers a new prototype in drug delivery that could be used for secondary and tertiary levels of drug targeting. Hence, solid lipid nanoparticles hold great promise for reaching the goal of controlled and site specific drug delivery and hence have attracted wide attention of researchers. This review presents a broad treatment of solid lipid nanoparticles discussing their advantages, limitations and their possible remedies. The different types of nanocarriers which were based on solid lipid like solid lipid nanoparticles, nanostructured lipid carriers, lipid drug conjugates are discussed with their structural differences. Different production methods which are suitable for large scale production and applications of solid lipid nanoparticles are described. Appropriate analytical techniques for characterization of solid lipid nanoparticles like photon correlation spectroscopy, scanning electron microscopy, differential scanning calorimetry are highlighted. Aspects of solid lipid nanoparticles route of administration and their biodistribution are also incorporated. If appropriately investigated, solid lipid nanoparticles may open new vistas in therapy of complex diseases.

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A type of dosage form (similar to the liposomal drug delivery system), w/o/w liquid membrane capsular delivery system, has been developed for controlling the drug release. Chlorpheniramine maleate was used as a model drug. Extensive work was planned and meticulously executed for evolving a stabilization process of the designed multiple emulsion. The problem was tackled from diflerent angles such as choice of emulsifier and viscosity builder and their concentrations, the HLB values of the emulsijiers, phase volume ratio both in case of primary emulsijication (4 w/o), and secondary emulsijication (4 w/o/w), manufacturing procedures, etc., from the first to the last step. Study of various parameters ultimately culminated in a marketable stable product rhat is expected to keep its physical stability over a period of 12 to 18 months, which will cover the usual shelflife of a pharmaceutical preparation. Evaluation of this system showed a gradual and consistent drug release from the delivery system by a modified dialysis method through Visking selective permeable tubing.

As a consequence of modern drug discovery techniques, there has been a steady increase in the number of new pharmacologically active lipophilic compounds that are poorly water soluble and solubility is one of the most important parameter to achieve desired concentration of drug in systemic circulation for therapeutic response. It is a great challenge for pharmaceutical scientist to convert those molecules into orally administered formulation with sufficient bioavailability.  Among the several approaches to improve oral bioavailability of these molecules, Self-micron emulsifying drug delivery system (SMEDDS) is one of the approaches usually used to improve the bioavailability of hydrophobic drugs. However, conventional SMEDDS are mostly prepared in a liquid form, which can have several disadvantages. Accordingly, solid SMEDDS (S-SMEDDS) prepared by solidification of liquid/semisolid self-micron emulsifying (SME) ingredients into powders have gained popularity. This article provides an overview of the recent advancements in S-SMEDDS such as methodology, techniques and future research directions.