Preparation, Characterization and Applications of Nanoemulsions: An Insight

Nanoemulsions are defined as isotropic, thermodynamically stable, transparent or translucent; dispersions of oil and water stabilized by surfactant molecules (forms an interfacial film) having the droplet size of 20-500nm. Ease of preparation and scale-up, stability and increased bioavailability are features of these formulations which have attracted the attention of researchers. Its basic principle lies in its ability to spontaneously generate fine o/w microemulsion under mild agitation following dilution with aqueous phases. These conditions mimic the digestive motility in the GIT necessary to provide the agitation required for In vivo self emulsification. Unlike emulsions, self-nanoemulsified drug delivery systems (SNEDDS) generates microemulsion with a narrow droplet size distribution of less than 50 nm due to which these systems have also been addressed as nanoemulsions. Nanoemulsions (NE) are lipidic nanoformulations with droplet diameter in nanometer range have established tremendous attention as drug delivery formulations for lipophilic drugs due to their capability to increase solubility, permeation across biological membranes as well as their therapeutic efficiency of lipid soluble drugs due to predictable size-distribution, high drug loading and stability under biological environment. However there is still relatively narrow insight regarding preparation, characterization and applications of nanoemulsions. This limitation unfolds the premise for current review article. In this review, we attempt to explore varying intricacies, methods of preparation, characteristics, and drug delivery applications of nanoemulsions to spike interest of those contemplating a foray in this field. Keywords: Nanoemulsions, Novel drug delivery system, increased bioavailability

Pharmacognostic Standardization and Phytochemical Evaluation of Ailanthus altissima (Mill.) Swingle leaves

The present study was focussed to carry out the detailed pharmacognostic studies in terms of organoleptic characters, physicochemical parameters, macroscopical, microscopical characters and phytochemical screening for major groups of compounds and other WHO recommended parameters for standardization of the leaves of (Mill.) family Simaroubaceae. Phytochemical screening of methanolic and aqueous extracts of leaves of Ailanthus altissima demonstrated the presence of Carbohydrates, flavonoids, tannins, cardiac glycosides, phenols, saponins, diterpenes, fats and oils. However alkaloids and anthraquinone glycosides were found absent in all the extracts. Information obtained from phytochemical and pharmacognostical analysis can be used as markers in the identification and standardization of this plant for monograph development and as herbal remedy. Keywords: Tree of heaven, Phytochemical, Pharmacognostic analysis, Bioactive compounds, Ailanthus altissima

Floating Oral In-Situ Gel: A Review

The drugs having a narrow absorption window in the gastrointestinal tract (GIT) when administered by oral route are often limited by poor bioavailability due to incomplete drug release and short residence time at the site of absorption. Novel drug delivery systems in the form of gastroretentive systems such as floating systems, mucoadhesive, high-density, expandable have been developed as they provide controlled delivery of drugs with prolonged gastric residence time. Liquid orals are more prone to low bioavailability because they are eliminated quickly from the stomach since they are subjected to faster transit from the stomach/ duodenum. The problems of immediate release and short gastrointestinal residence of liquids are eliminated by formulating as oral in situ gels as they provide the best means to overcome these problems The in situ gel dosage form is a liquid before administration and after it comes in contact with gastric contents due to one or more mechanisms gets converted to gel which floats on gastric contents. This achieves increased residence as well as sustained release. This approach is useful for systemic as well as local effect of drugs administered. This review gives a brief idea about floating oral in-situ gel formation and research done by various scientists on a number of drugs and polymers. Keywords: Floating drug delivery, gastric retention time, In-situ gel