Layered Tablets: A Novel Oral Solid Dosage Form

Oral solid dosage forms hold a predominant position in the drug delivery system. Tablets are the most widely used and convenient dosage form. Due to their ease of manufacturing, the minimum cost of production, easy handling and storage, and better stability, tablets are most preferred. Patients who are prescribed more than one drug are in a situation to consume multiple tablets. To minimize the counts, one or more drugs are cast into layers to form a single tablet, thus called layered tablets. Layered tablets tend to improve patient compliance and reduce the cost of production by half. Layers can be of multiple drugs or the same drug at different doses or drugs with release enhancers or drugs with fillers. Layered tablets hold a greater potential with better patient outcomes as well as stay production-friendly

Hydrographical parameters and phytoplankton assemblages along the Pondicherry–Nagapattinam coastal waters, southeast coast of India

Hydrographical parameters and phytoplankton assemblages were determined along the Pondicherry, Parangipettai and Nagapattinam coastal waters, southeast coast of India. All the hydrographical parameters such as sea surface temperature, salinity, pH, total alkalinity, dissolved oxygen and nutrients like nitrate, nitrite, inorganic phosphate and reactive silicate, chlorophyll a and phytoplankton assemblages were studied for a period of five months (May, August, September 2010, March and November 2011). Over 121 species of phytoplankton represented by 93 species of diatoms, 16 species of dinoflagellates, 9 species of blue-green algae, 2 species of greens and 1 species of silicoflagellate were recorded. High phytoplankton species diversity was found in March 2011 when salinity and nitrate concentrations were low and reactive silicate and inorganic phosphates were moderate. Species diversity was low during May 2010 when increased sea surface temperature, salinity and low nutrients availability were observed. Coscinodiscus centralis, Diatoma vulgaris and Proboscia alata were dominant, especially Coscinodiscus sp. distributed in all stations whereas Skeletonema costatum, Odontella sinensis and Ditylum brightwellii were abundant in August and September 2010. From principal component analysis and multiple regression analysis, it is evident that variables like sea surface temperature and dissolved oxygen are the most important factors influencing the seasonal pattern of phytoplankton population