Formulation and Development of Bilayer Floating Tablet of Nifedipine using surface solid dispersion technique

The aim of the present work was to develop formulation of Nifedipine in the form of bilayer floating sustained release tablet. Bilayer consist of a two layers, immediate release layer and second sustained release layer, compressed in single unit dosage form. Immediate release layer contains surface solid dispersion of Nifedipine and Floating sustained release layer also contain surface solid dispersion of Nifedipine by using HPMC K100M and HPMC K15M as sustained release polymer. Nifedipine is an antihypertensive drug. Surface solid dispersion of Nifedipine was prepared by solvent evaporation method with different super disintegrant as a polymer for improvement of solubility resulting in improved bioavailability. In the present study Nifedipine bilayer floating controlled release tablet were prepared with the help of direct compression method, using sodium bicarbonate and citric acid which generate gas upon contact with gastric fluid. Immediate release layer releases the drug immediately and floating sustained release layer floats on gastric fluid for upto12 hours and releases the drug in sustained manner, subsequently it prolongs duration of action. The tablets were evaluated for various physical parameters, buoyancy studies, dissolution studies and drug released mechanisms. The batch number F5 formulation showed minimum disintegration time of immediate release layer (24 sec) and gave maximum swelling index of the sustained release layer (82.8%) and also maximum drug release duration of Nifedipine spread over 12 hours

Development and evaluation of bilayer tablets of combination of antibiotics for the treatment of sexually transmitted disease

The present research work was envisaged to develop bilayer tablets to improve therapeutic efficacy of antibiotic combination for the treatment of sexually transmitted diseases. The combination of two antibiotics i.e. cefixime trihydrate and ofloxacin were used for the preparation of bilayer tablets which act against genito-urinary infections. The formulations comprise of cefixime trihydrate as immediate release layer formulated using different superdisintegrants and ofloxacin as extended release layer containing HPMC K100M. Evaluation of bilayer tablets were performed for the immediate release cefixime layer and sustain release ofloxacin layer with optimization of excipients. The immediate release layer of cefixime showed complete release within 30 min and ofloxacin release was extended up to 24 hours. The similarity factor value of ofloxacin sustained release layer was found to be 87.01 for initial and 80.35 after 3 months stability when compared with marketed reference product. The present study revealed that cefixime trihydrate and ofloxacin bilayer tablets were successfully developed for the use against sexually transmitted infections

DESIGN AND IN VIVO EVALUATION OF METOPROLOL TARTRATE BILAYER FLOATING TABLETS IN HEALTHY HUMAN VOLUNTEERS

The aim of the present investigation was to prepare bilayer floating tablets of metoprolol tartrate using the combination of superdisintigrants, HPMC K grade polymers and natural polymers like xanthan gum and guar gum by direct compression method. Bilayer floating tablets were prepared using optimized immediate release layer and floating layer as sustained release layer. The physico-chemical characteristics of the prepared tablets were evaluated and found to be satisfactory. All the prepared batches showed in vitro buoyancy. It was observed that the tablets remained buoyant for more than 12 h.  Formulation F7 was selected as best formulation based on the in vitro characteristics and used in vivo radiographic studies by adding barium sulphate. These studies revealed that the tablets remained in the stomach for 210±5.4 min (n=3) in fasting human volunteers. Based on the in vivo performance in healthy subjects, the developed bilayer floating tablets showed superior bioavailability than the marketed tablets, the drug release was up to 12 h in controlled manner. The systemic availability of the best formulation was high after administration to obtain immediate action due to the immediate release layer, from sustained release layer the drug was released in controlled manner. It can be concluded that the best formulation F7 by choosing biphasic drug release pattern in a single dosage form could improve patient compliance and ensure better disease management

An exothermal energy release layer for microchip transience

pre-printA single layer nanothermite spin coated gel has been utilized as a solid-state exothermic energy release layer for triggered microchip transience. A proportional combination of self-assembled CuO/Al nanothermite and Napalm-B as gelling agent has been used to develop for the first time a spinable nanothermite film onto the surface of a micro-chip. This layer when ignited instantaneously releases enough heat energy to melt the surface of the underlying substrate and any surface-bound microdevices, electronic feature or any surface deposited component. We observe the effect of thermite enabled destruction prior and post ignition through microscopic imaging and electrical measurements on surface bound components

Towards production of novel catalyst powders from supported size-selected clusters by multilayer deposition and dicing

A multilayer deposition method has been developed with the potential to capture and process atomic clusters generated by a high flux cluster beam source. In this deposition mode a series of sandwich structures each consisting of three layers—a carbon support layer, cluster layer and polymer release layer—is sequentially deposited to form a stack of isolated cluster layers, as confirmed by through-focal aberration-corrected HAADF STEM analysis. The stack can then be diced into small pieces by a mechanical saw. The diced pieces are immersed in solvent to dissolve the polymer release layer and form small platelets of supported clusters

Preferentially Etched Epitaxial Liftoff of InP Material

The present invention is directed toward a method of removing epitaxial substrates from host substrates. A sacrificial release layer of ternary material is placed on the substrate. A layer of InP is then placed on the ternary material. Afterward a layer of wax is applied to the InP layer to apply compressive force and an etchant material is used to remove the sacrificial release layer

Preferentially etched epitaxial liftoff of InP material

The present invention is directed toward a method of removing epitaxial substrates from host substrates. A sacrificial release layer of ternary material is placed on the substrate. A layer of InP is then placed on the ternary material. Afterward a layer of wax is applied to the InP layer to apply compressive force and an etchant material is used to remove the sacrificial release layer

DEVELOPMENT AND EVALUATION OF BILAYER TABLETS FOR IMMEDIATE AND CONTROLLED RELEASE OF METFORMIN HYDROCHLORIDE

Objective: The purpose of this study was to develop and evaluate bi-layer tablets for the immediate and controlled release of Metformin Hydrochloride for effective treatment of type 2 Diabetes mellitus. Methods: The immediate release layer was prepared by using super disintegrants like cross carmellose sodium, sodium starch glycolate and sustained release layer was prepared by using hydrophilic polymer like HPMC K 100 and PVP. Various proportions of super disintegrants and polymer were used to select the best formulation composition. Bilayer tablet of metformin was prepared by wet granulation method and was evaluated for physical characteristics like hardness, weight variation, and friability. In vitro release of drug was performed in USP type II dissolution test apparatus using phosphate buffer (pH 6.8) as dissolution media and dissolution was continued for 9 h for the sustained release layer. For immediate release layer, readings were recorded in each 10 min time interval for the first 1h. Results: From the obtained result it was found that all the formulations were within the limit of the standard. The hardness was found to be in the ranges from 5.1 to 5.5 kg/cm2, weight variation was in the range 0.53% to 0.83%, friability of all the formulations was within the range (<1%)and percentage of drug content was more than 97%. The drug release of the tablet was in the range of 85%-91% in 9 h. Conclusion: From the result obtained, it is found that the formulation F6 satisfies all the criteria as sustained release tablet for the effective treatment of type 2Diabetes mellitus