The aim of the present study was to enhance the dissolution rate of gliclazide using its solid dispersions (SDs) with polyethylene glycol (PEG) 6000. The phase solubility behavior of gliclazide in presence of various concentrations of PEG 6000 in 0.1 N HCl was obtained at 37 degrees C. The solubility of gliclazide increased with increasing amount of PEG 6000 in water. Gibbs free energy (deltaG(o)(tr)) values were all negative, indicating the spontaneous nature of gliclazide solubilization and they decreased with increase in the PEG 6000 concentration, demonstrating that the reaction conditions became more favorable as the concentration of PEG 6000 increased. The SDs of gliclazide with PEG 6000 were prepared at 1:1, 1:2 and 1:5 (gliclazide/PEG 6000) ratio by melting-solvent method and solvent evaporation method. Evaluation of the properties of the SDs was performed by using dissolution, Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. The SDs of gliclazide with PEG 6000 exhibited enhanced dissolution rate of gliclazide, and the rate increased with increasing concentration of PEG 6000 in SDs. Mean dissolution time (MDT)of gliclazide decreased significantly after preparation of SDs and physical mixture with PEG 6000. The FTIR spectroscopic studies showed the stability of gliclazide and absence of well-defined gliclazide-PEG 6000 interaction. The DSC and XRD studies indicated the microcrystalline or amorphous state of gliclazide in SDs of gliclazide with PEG 6000.

The review article aims to highlight the recent developments in various in situ gel-forming polymeric systems that are used to achieve prolonged contact time of drugs with the cornea and increase their ocular bioavailability. These phase-change polymers, which trigger the drug release in response to external stimuli, are the most investigated in controlled drug delivery. The present review summarizes in detail these various polymers, which undergo sol-gel transition due to physical (temperature) or chemical (pH, ions) stimuli when instilled in the eye. As a whole, this article provides valuable insight into current trends in the field of in situ gel-forming ocular drug delivery systems.

The present investigations highlight the development of solid self-emulsifying drug delivery system (solid-SEDDS) for improved oral delivery of the poorly water-soluble drug; cilnidipine. Liquid SEDDS of the drug were formulated using Capryol 90 as the oil phase, Tween 80 as the surfactant, and Transcutol HP as the co-surfactant after screening various vehicles. The prepared systems were characterized for selfemulsification time, robustness to dilution, % transmittance, globule size, drug release, and thermodynamic stability. Ternary phase diagrams were plotted to identify the area of microemulsification. The optimized liquid SEDDS was transformed into a free-flowing powder using Neusilin US2 as the adsorbent. Solid selfemulsifying powder retained the self-emulsifying property of the liquid SEDDS. Differential scanning calorimetric, X-ray powder diffraction studies revealed the possibility of transformation of the crystalline form of the drug to the amorphous form in the SEDDS prepared with the carrier. The morphology of solid-SEDDS from scanning electron microscopy studies demonstrated the presence of spherical, granular particles indicating good flowing ability. Dissolution studies revealed enhanced dissolution of the drug from the solid system compared with the pure drug and its marketed formulation. Similarly, the in vitro absorption profile of the drug from the formulated SEDDS was significantly higher compared with pure drug. Thus it can be concluded that solid-SEDDS, amenable for development of solid dosage form, can be successfully developed using Neusilin US2 with the potential of enhancing the solubility, dissolution rate, and bioavailability of the drug. Key words cilnidipine; solid self-emulsifying drug delivery system (SEDDS); adsorption; crystallinity; droplet size; drug release Poorly water-soluble drug candidates often emerge from contemporary drug discovery programs, and present formulators with considerable technical challenges. The absorption of such compounds when presented in the crystalline state to the gastrointestinal tract is typically dissolution rate-limited, and the drugs are typically Biopharmaceutical Classification System (BCS) class II or class IV compounds.1) The interests on lipid-based drug delivery systems (LBDDS) have increased over the past two decades as a function of identification of these pharmaceutically difficult candidates, and increased even further after successful launch of lipid-based oral pharmaceutical products, including in particular cyclosporine A, marketed as Sandimmune and Neoral . 2)Lipid based drug delivery system such as self-emulsifying drug delivery systems (SEDDS) are mixtures of oils and surfactants, ideally isotropic, sometimes including cosolvents, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastrointestinal tract. Hydrophobic drugs can often be dissolved in SEDDS allowing them to be encapsulated as unit dosage forms for peroral administration.3-5) When such a system is released in the lum...

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Damar Batu (DB) looks like stone with black or dark brown color inside. Due to its film forming ability it is used in the manufacture of paper, wood, varnishes, lacquers, polishes and additives for beverages. In the present study the permeability of free films of DB casted from chloroform solution containing different plasticizers was studied with a view to developing a suitable rate controlling membrane for transdermal use. The free films of DB were prepared by a mercury substrate technique and dibutyl sebacate (DBS), dibutyl phthalate (DBP), polyethylene glycol 400 (PEG400) and propylene glycol (PG) were tried as plasticizers. DB films were then evaluated for uniformity of thickness, moisture absorption, water vapour transmission, tensile strength, percentage elongation and folding endurance. Permeability characteristics of free films of DB were studied using diltiazem hydrochloride (DH) as a model drug. Little variation in film thickness ensured the uniformity of the films. DBS produces tough DB films with more tensile strength. Drug diffusion through the free films followed zero order kinetics. The films plasticized with PEG400 showed higher permeability for DH compared with other films. The order of decrease of permeability of plasticized films with plasticizers was PEG400 > PG > DBP > DBS. Diffusion of drugs through the free films of DB was extended over a longer period of time at a controlled rate. DB seems to be a promising rate controlling membrane for the transdermal application.