Razvoj i vrednovanje dvoslojnih tableta propranolol hidroklorida

The objective of the present research was to develop a bilayer tablet of propranolol hydrochloride using superdisintegrant sodium starch glycolate for the fast release layer and water immiscible polymers such as ethyl cellulose, Eudragit RLPO and Eudragit RSPO for the sustaining layer. In vitro dissolution studies were carried out in a USP 24 apparatus I. The formulations gave an initial burst effect to provide the loading dose of the drug followed by sustained release for 12 hrs from the sustaining layer of matrix embedded tablets. In vitro dissolution kinetics followed the Higuchi model via a non-Fickian diffusion controlled release mechanism after the initial burst release. FT-IR studies revealed that there was no interaction between the drug and polymers used in the study. Statistical analysis (ANOVA) showed no significant difference in the cumulative amount of drug release after 15 min, but significant difference (p 0.005) in the amount of drug released after 12 h from optimized formulations was observed.U radu je opisan razvoj dvoslojnih tableta propranolol hidroklorida, koristeći superdezintegrator škrob glikolat natrij u sloju za brzo oslobađanje i polimere koji se ne miješaju s vodom (etil celuloza, Eudragit RLPO i Eudragit RSPO) u sloju za usporeno oslobađanje. In vitro oslobađanje praćeno je u USP aparatu I te je uočeno početno naglo oslobađanje ljekovite tvari iza kojeg slijedi polagano oslobađanje tijekom 12 sati. In vitro kinetika oslobađanja prati Higouchijev model, dok mehanizam kontroliranog oslobađanja ne slijedi Fickov zakon poslije početnog naglog oslobađanja. FT-IR studije ukazuju da nema interakcije između ljekovite tvari i polimera upotrebljenih u oblikovanju. Statistička analiza (ANOVA) nije pokazala značajne razlike u kumulativnoj količini oslobođenog lijeka iz optimiranih formulacija poslije 15 minuta i polije 12 h

An animation-and-chirplet based approach to intruder classification using PIR sensing

The development of a Passive Infra-Red (PIR) sensing based intrusion detection system is presented here having the ability to reject vegetative clutter and distinguish between human and animal intrusions. This has potential application to reducing human-animal conflicts in the vicinity of a wildlife park. The system takes on the form of a sensor-tower platform (STP) and was developed in-house. It employs a sensor array that endows the platform with a spatial-resolution capability. Given the difficulty of collecting data involving animal motion, a simulation tool was created with the aid of Blender and OpenGL software that is capable of quickly generating streams of human and animal-intrusion data. The generated data was then examined to identify a suitable collection of features that are useful in classification. The features selected corresponded to parameters that model the received signal as the superimposition of a fixed number of chirplets, an energy signature and a cross-correlation parameter. The resultant feature vector was then passed on to a Support Vector Machine (SVM) for classification. This approach to classification was validated by making use of real-world data collected by the STP which showed both STP design as well as classification technique employed to be quite effective. The average classification accuracy with both real and simulated data was in excess of 94%

Chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol

<p>Abstract</p> <p>Background and the purpose of the study</p> <p>Carvedilol nonselective β-adrenoreceptor blocker, chemically (±)-1-(Carbazol-4-yloxy)-3-[[2-(o-methoxypHenoxy) ethyl] amino]-2-propanol, slightly soluble in ethyl ether; and practically insoluble in water, gastric fluid (simulated, TS, pH 1.1), and intestinal fluid (simulated, TS without pancreatin, pH 7.5) Compounds with aqueous solubility less than 1% W/V often represents dissolution rate limited absorption. There is need to enhance the dissolution rate of carvedilol. The objective of our present investigation was to compare chitosan and chitosan chlorhydrate based various approaches for enhancement of dissolution rate of carvedilol.</p> <p>Methods</p> <p>The different formulations were prepared by different methods like solvent change approach to prepare hydrosols, solvent evaporation technique to form solid dispersions and cogrind mixtures. The prepared formulations were characterized in terms of saturation solubility, drug content, infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), electron microscopy, <it>in vitro</it> dissolution studies and stability studies.</p> <p>Results</p> <p>The practical yield in case of hydrosols was ranged from 59.76 to 92.32%. The drug content was found to uniform among the different batches of hydrosols, cogrind mixture and solid dispersions ranged from 98.24 to 99.89%. There was significant improvement in dissolution rate of carvedilol with chitosan chlorhdyrate as compare to chitosan and explanation to this behavior was found in the differences in the wetting, solubilities and swelling capacity of the chitosan and chitosan salts, chitosan chlorhydrate rapidly wet and dissolve upon its incorporation into the dissolution medium, whereas the chitosan base, less water soluble, would take more time to dissolve.</p> <p>Conclusion</p> <p>This technique is scalable and valuable in manufacturing process in future for enhancement of dissolution of poorly water soluble drugs.</p