Abstract The objective of the present investigation was to design, optimize and characterize the gastro retentive floating levofloxacin tablets and perform in-vivo evaluation using radiographic imaging. The floating tablets were prepared by using polymers i.e hydroxy propyl methyl cellulose (HPMC-K4M) and carbopol-940 individually and in combination by nonaquous granulation method. All the Formulations were evaluated for swelling index (S.I), floating behavior and in-vitro drug release kinetics. The compatibility study of levofloxacin with other polymers was investigated by FTIR, DSC, TGA and XRD. Results from FTIR and DSC revealed no chemical interaction amongst the formulation components. The optimized formulation (F11) showed floating lag time (FLT), total floating time (TFT) swelling index (S.I) of 60 sec, >16h and approximately 75 %, respectively. Moreover, F11 showed zero order levofloxacin release in simulated gastric fluid over the period of 6 h. X-ray studies showed that total buoyancy time was able to delay the gastric emptying of levofloxacin floating tablets in rabbits for more than 4 hours. In conclusion the optimized formulation (F11) can be used for the sustained delivery of levofloxacin for the treatment of peptic ulcer.

ABSTRACT The house fly, Musca domestica L. (Diptera: Muscidae), is a major pest of all aspects of life, like the domestic, medical and veterinary and causal agent of several pathogenic diseases. The present study was conducted to evaluate the potential of different insecticide-free baits against house fly by incorporating flower methanol extract of Helianthus annuus (sunflower) and Tegetes erecta (marigold) at 10%, 20% and 30% bait formulation of corn syrup, dried milk and water. However, imidacloprid and thiacloprid (each at 5% concentration) were also included in the study for comparison. Results showed that insecticide baits were superior in causing mortality of adult house fly but dependent upon syrup. Overall, 20% baits of both extracts caused more than half population death of house fly within 48h. On the other hand, the mortality rate by 30% baits (from sunflower and marigold) had a similar impact as observed in case of imidacloprid and thiacloprid baits. Therefore, biological baits could play a more active and safer role in the management of house fly as compared to synthetic insecticides.

The aim of present work was to investigate blends of Eudragit® NE 30D with Aquacoat® ECD using different ratios to eliminate curing effect associated with individual polymers. Propranolol HCl 10% w/w was layered onto sugar cores using 5% w/w HPMC as a binder. Drug-layered-cores were coated either with pure or blends of Aquacoat® ECD: Eudragit® NE 30D in a fluidized bed coater to obtain 20% w/w coating level. Talc 35% w/w was used as anti-tacking agent. The pellets were characterized for in vitro dissolution studies, morphology, water uptake-weight loss, osmolality and adhesion of coating after curing at 60 °C or 60 °C/75% RH for 24 h. The findings revealed that Aquacoat® ECD coated pellets showed curing effect due to further gradual coalescence of polymeric particles which resulted into better film formation upon curing. In contrast, the curing effect of Eudragit® NE 30D coated pellets was caused by decrease in adhesion of coatings after curing which provided entirely different swelling behavior of uncured (localized swelling) and cured (uniform swelling) pellets. The undesired curing effect of individual polymers was eliminated by using their blends in appropriate ratio.

Abstract Synthetic wood preservatives are the causes of large-scale environmental pollution and few have been withdrawn from the commercial markets in the past years. The present studies focused on determination of naturally present extractives of Ziziphus mauritiana as less toxic wood protectant against subterranean termites. Firstly, natural resistance of Z. mauritiana heartwood against termite was determined by exposing stakes in the field. For the preparation of extractives, air-dried Z. mauritiana heartwood and bark shavings were soaked in 1 liter each of ethyl acetate, hexane, petroleum ether and water in a bottle separately. Different dipping treatment times (36 and 72 hours) at 10, 20 and 30% concentrations of extractives on Populus deltoides wooden stakes were used and stakes were exposed to termites in submerged manner. Combination of extractives in different solvents were included as separate experiment and finally, seasoning prior to extractives application on P. deltoides wooden stakes was also done and stakes were arranged in three replications for each treatment. Maximum mean percent weight loss (81.1%) was observed in case of P. deltoides followed by boiled Z. mauritiana (15.24%) in termite resistance test. Stakes treated with petroleum ether extracts had minimum weight loss alone or in combination with other extract’s solvent in all experiments. Extractives in other solvents followed petroleum ether non-significantly but were significantly different from their respective control treatment, which had the highest weight loss (>60%). Transferring durability using extracts of Z. mauritiana increased resistance of non-durable P. deltoides against termites and extractives could be used as wood preservatives.

RESUMO O presente estudo descreve o desenvolvimento de microcápsulas de teofilina pelo método sem adição de solvente e o efeito da adição de plastificante na microencapsulação. A liberação foi estudada em água destilada e os dados foram analisados por vários modelos matemáticos para determinação do mecanismo de liberação. As microcápsulas preparadas mostraram-se esféricas, livres de corrente e com mais de 80% de fármaco encapsulado. O polímero - ftalato de acetato de celulose e o plastificante - polietileno glicol - afetaram as propriedades das microcápsulas, incluindo a liberação do fármaco (tempo para liberação de 50% do fármaco, T50). A formulação com a maior proporção de polímero e sem plastificante (F3) se mostrou como a de liberação mais lenta, com T50 = 4,3 h, enquanto as formulações com menor proporção de polímero e 20% de plastificante (m/m) (F13 &14) apresentaram a liberação mais rápida do fármaco, com T50 de 1,2 h e 1,3 h, respectivamente. A liberação do fármaco para a maioria das formulações seguiu o modelo de Higuchi. Concluiu-se, dos resultados do presente estudo, que o ftalato do acetato de celulose afeta significativamente a liberação controlada do fármaco em água, enquanto que a adição de polietileno glicol aumenta ligeiramente a liberação do fármaco.

ABSTRACT The present study describes the development of theophylline microcapsules by a non-solvent addition method and the effect of plasticizer addition on microencapsulation. The release was studied in distilled water and the data were analysed by various mathematical models for determining the mechanism of release. Prepared microcapsules were found to be spherical, free flowing and having more than 80% entrapped drug. The polymer - cellulose acetate phthalate and plasticizer - polyethylene glycol was considered to be affecting the properties of microcapsules including drug release (time for 50% drug release, T50). The formulation with the highest proportion of polymer and without plasticizer (F3) showed the slowest release with T50 = 4.3 h, while the formulation with lower proportion of polymer and 20% (w/w) plasticizer (F13 &14) showed the fastest release of drug with T50 values of 1.2 h and 1.3 h, respectively. The drug release from most of the formulations was found to be following Higuchi model. It is concluded from the results of the present study that cellulose acetate phthalate significantly affects the sustained release of the drug in water, whereas the addition of polyethylene glycol slightly enhances the drug release.