Current Issue : October - December Volume : 2010 Issue Number : 3 Articles : 8 Articles
Theophylline is a dimethylated xanthine has been prescribed as bronchodilator, cardiotonic, diuretic and respiratory stimulant. The main objective of this work is to formulate and evaluate Theophylline bi layered floating tablets by using different hydrophilic polymers. In order to obviate the demerit of the limited residence time of the controlled release dosage form in the gastrointestinal tract and to increase the duration of release, the intra-gastric hydrodynamically balanced or floating system was conceived. Double layered tablet is attempted to incorporate the loading dose in the immediate release layer so that, the minimum effective concentration may be attained within a shorter time after which the maintenance of the level will be taken over by the drug release from the second layer. To develop the formulae and prepare the two layered intra gastric floating drug delivery system of theophylline with hydrophilic polymers such as hydroxy propyl methyl cellulose (HPMC), sodium carboxy methyl cellulose (NaCMC) and methyl cellulose (MC) each alone or in combination in different drug and polymer ratios and the prepared tablet are evaluated for various physico-chemical parameters such as Hardness, Weight variation, Disintegration of first layer, Swelling thickness, Drug content, Friability, Floating time, In vitro drug release and the best formulation is compared with that of commercially available formulation of theophylline. The results show that, the type of polymer and the drug: polymer used in the tablets influences the physic-chemical characters like thickness, swelling thickness, floating time....
The low bioavailability and ocular residence time exhibited by the topical conventional liquid ophthalmic formulations because of spillage by overflow, dilution of drug by tear turn over, nacolacrimal drainage and systemic absorption may be overcome by the use of in-situ forming system that are instilled as liquid into the cul-de-sac of the eye. The present work made to attempt and ophthalmic controlled drug delivery system of an anti-bacterial agent, levofloxacin base on the concept of pH induced in-situ gellation. The acrypol 941 and 980 (carbopol grade) use as a gelling agent with viscolyzers like methyl cellulose, hydroxy ethyl cellulose, hydroxyl propyl methyl cellulose (K 15) was added for ocular viscosity enhancing agent. Formulation was evaluated for drug content uniformity, viscosity, in-vitro gellation study and in-vitro released study. The rheological behavior of gel formulation was not affected by in corporation of levofloxacin. The result demonstrates that formulation contains the acrypol 980 /HPMC mixture can be used as in-situ gelling vehicle to enhance ocular bioavailability and patient compliance....
In this review, we discuss cancer imaging and gene delivery system The attractive features of gold nanoparticles include their surface plasmon resonance, the controlled manner in which they interact with thiol groups, and their non-toxic nature. These attributes can be exploited to provide an effective and selective platform to obtain a targeted intracellular release of some substance. The use of gold nanoparticles can also increase the stability of the payload. Here we review recent advances in the use of gold nanoparticles in gene delivery systems and cancer imaging....
“VISION 2020, THE RIGHT TO SIGHT” was the global initiative launched in the year 1999. Drug delivery to the inner eye is still a challenge in ocular therapeutics. Topical administration of drugs to treat ocular disease is accomplished primarily by means of solutions, ointments, and suspensions. These are relatively inefficient as drug delivery systems; often only 1% of the available drug is absorbed by the eye. Ocular iontophoresis is a non-invasive technique which provide convenient route of administration of many therapeutics indications. This review highlights on the basic concept of ocular iontophoresis, iontophoretic device, transcorneal and transscleral iontophoresis of different drugs, emphasizing the current density applied and the treatment duration used by the investigators....
In the present study once daily esomeprazole controlled release tablet was prepared by utilizing carbopol as the primary polymer and different grades of hydroxypropyl methylcellulose (HPMC) as the secondary polymers such as Methocel K4M & Methocel K15 M by direct compression method.Carbopol was kept constant and different amount of Methocel K 4 M & Methocel K15 M was used to develop once daily esomeprazole in the nine proposed formulations (FA1-FC3). The dissolution study of those proposed formulations were carried out in the simulated gastric medium (pH 1.3) for first two hours and then in the simulated intestinal medium (pH 6.8) for 24 hours using USP dissolution apparatus II. The formulation FB2 met the optimum release rate of esomeprazole for 24 hours period of in vitro dissolution study and considered as the best formulation comparing to others. The release kinetics of formulation FB2 very closely followed Higuchi mechanism and zero order kinetics. Mucoadhesive strength study was carried out for the optimized formulation FB2 using goat intestine and shows high mucoadhesive strength. One month stability study was performed for optimized formulation FB2 and complies within the limit....
Multiple emulsions are complex systems, termed "emulsions of emulsions", i.e. the droplets of the dispersed phase contain even smaller dispersed droplets themselves. Each dispersed globule in the double emulsion forms a vesicular structure with single or multiple aqueous compartments separated from the aqueous phase by a layer of oil phase compartments. The multiple emulsions are considered to be promising drug delivery systems by virtue of their thermodynamic stability, macroscopic homogeneity, ease of preparation and small droplet size . Multiple emulsions of w/o/w and o/w/o types (more correctly, double emulsions) are becoming popular since an additional reservoir is presented to the drug for partitioning which can effectively retard it release rate. This parenteral multiple emulsion have many advantages such as which include ease of application, localized delivery for a specific action. Prolonged delivery period, decreasing body drug dosage with concurrent reduction in the possible undesirable side effect common to most form of systemic delivery and improved patient compliance and comfort. By the incorporation of combined chemotherapeutic agents in the parenteral multiple emulsion enables the simultaneous attack of different biological targets, thus enhancing the effectiveness of treatment and they are less likely than older tumors to develop drug resistance....
This work was aimed at developing controlled release amoxicillin trihydrate (MOX) mucoadhesive microspheres to reduce adverse effects, to enhance therapeutic efficacy and to avoid development of resistance for gastric infections. Chitosan, a cationic polymer was selected as and sodium carboxymethyl cellulose (Na CMC), an anionic polymer was selected for mucoadhesion and sustained release respectively. The preparation of microspheres was carried out using ionic gelation method. The prepared microspheres were evaluated for their morphology (shape & size), percentage drug entrapment, in vitro drug release studies and mucoadhesion test on excised stomach mucosa of an albino rat. Prepared microspheres were sphericalin shape with particle size of 30 – 50 m. The percent drug entrapment was found to be around 20%. release profile followed zero order kinetic with around 20 % constant drug release per hour up to 5 hours. Mucoadhesion test suggest microspheres were adhesive to rat stomach mucosa. Therefore, it is safely concluded that mucoadhesive controlled release microspheres of amoxicillin were successfully developed and can be used for optimum delivery of MOX either for local gastric infections or for systemic drug delivery....
The multiple emulsion formulations containing Atorvastatin were optimized for oil phase; different formulation parameters like type and concentration of primary emulsifier & secondary emulsifier, phase volume ratio and effect of additives; and different process variables like speed and time of stirring for primary and secondary emulsification; on the basis of different evaluation parameters like entrapment efficiency, stability, globule size, viscosity and in vitro release profile. Atorvastatin is commonly used for the treatment of hyperlipidemia or hypercholesterolemia but it suffers from the problem of low bioavailability through oral route. Based on the hypothesis that improved release profile leads to enhanced bioavailability, the present study was aimed to optimize various processing parameters to obtain stable multiple emulsions with high encapsulation efficiency and improved release profile....
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