A R Shabaraya

Oral route has been considered as most convenient route but restricted to only hydrophilic compounds having GI stability and greater dissolution. The delivery of lipophilic compounds has been area of interest since most of the drugs under discovery shows limited bioavailability. Self-emulsifying delivery systems (SMEDDS) has drawn a greater attention in the formulation of poorly soluble compounds where increase in the absorption and permeation of the drug has observed. The self-emulsification which occurs in the case of SMEDDS has shown a potential advantage over conventional emulsion due to the fine globules formed upon dilution. The recent trends such as dry emulsion, s-SMEDDS, SNEDDS thoroughly investigated. This article, attempts to present the overview of the SMEDDS along with its formulation, application and characterization.

Colon targeted drug delivery system is capable of protecting the drug in route to the colon i.e. drug gets released and absorbed once it reaches the colon. A multiparticulate system combining pH sensitive property and biodegradability has been investigated to prepare and evaluate Eudragit S-100 coated Sodium alginate microspheres for colon targeting of Tramadol Hydrochloride. Uncoated Tramadol Hydrochloride microspheres were prepared by ionotropic gelation technique using different ratios of Tramadol Hydrochloride and Sodium alginate. Coated Tramadol Hydrochloride microspheres were prepared by coacervation phase separation technique using different ratios of uncoated Tramadol Hydrochloride and Eudragit S-100/ Eudragit L-100. Uncoated and coated Tramadol Hydrochloride microspheres were evaluated for percentage yield, particle size, surface morphology, flow properties, drug content and entrapment efficiency and were found to be within the acceptable range. The uncoated microspheres sustained the release upto 8 hrs whereas coated microspheres sustained the release upto 12 hrs in a pH progression medium mimicking the condition of GIT. The drug release from MC4 formulation coated with Eudragit S-100 (1:4) showed desired rate as there was no drug release observed upto 4-5 hrs, while in colonic fluid controlled drug release was observed releasing about 69.66 % after 12 hrs. The release kinetics followed Peppas showing Super Case II transport. Stability studies suggested formulations were stable. It is concluded from the present investigation that Eudragit S-100 coated Sodium alginate microspheres are promising controlled release carriers for colon targeted delivery of Tramadol Hydrochloride.

Fast dissolving tablets are the tablets which dissolves rapidly and shows higher bioavailability than conventional tablets. The concept of formulating Fast dissolving tablets of Loratadine (antiallergic drug) offer suitable and practical approach in serving the desired objective of faster disintegration and dissolution characteristic with increase bioavailability and to know the effects of three synthetic superdisintegrants (Crosscarmeloss sodium, Sodium starch glycolate and Crospovidone). In the present work two methods of solid dispersion were compared for improving the bioavailability i.e Solvent Evaporation and Fusion method with beta cyclodextrin as a carrier to increase the solubility of the drug. Comparison between these three synthetic superdisintegrants was done by taking different ratios individually and in combination. Combination of these three superdisintegrants shows synergistic effect when it is compared to individually. Prepared tablets were subjected to different evaluation parameters such as hardness, thickness, friability, weight variation, drug content uniformity, in vitro disintegration time, wetting time, in vitro dissolution studies and stability studies are carried out by using the best formulation. From all the formulations prepared and evaluated F11 was found to the best formulation. Key words: Fast dissolving tablets, Solid dispersion, Crosscarmeloss sodium, Sodium starch glycolate, Crospovidone, Evaluation parameters.

Gastro retentive drug delivery is an approach to prolong gastric residence time, thereby targeting site-specific drug release in the upper gastro intestinal tract (GIT) for local and systemic effect. The present study has been a satisfactory attempt to formulate floating drug delivery system of Valacyclovir, an orally administrated antiviral drug with a view of improving its oral bioavailability and giving sustained release of the drug. In present study design expert trial 8.0.6.1 software is used for designing of experiment. In central composite design based on response surface methodology yielded nine experimental runs. These nine formulations are evaluated for precompressional parameters like bulk density, tapped density, angle of repose and carr’s index. Formulations are also evaluated for postcompressional parameters like hardness, thickness, weight variation etc. all the formulations shows results in the acceptable range. All preliminary formulations are subjected to invitrobouyancy and dissolution study. The data obtained from the in vitro release study was fit to various kinetic models to explain the release profile of the drug. Kinetic models used were zero and first-order equations, Krosmeyersand peppas and Higuchi models. Based on results obtained from the prelimimary formulations five optimized formulations are selected and validated. Short-term stability study was done for optimized formulations.