Stone crushing unit workers suffer from particulate matters and respirable silica at work and in their residents nearby. The present study was undertaken to evaluate the area and personal exposure concentration of respirable particulate matters and silica in workplaces and in surrounding villages. PM 10 , PM 4 and PM 2.5 were considered for unit area measurement and PM 4 and PM 2.5 were considered for personal exposure measurements. The ambient PM 10 and indoor respirable particulate sampling and analyses were carried out in two neighboring villages adjacent to a cluster of 100 stone crushing units in central India. The study was conducted in two years with varied seasons to provide baseline data on the existing particulate concentration with and without control intervention. Monitoring and analytical criteria were fulfilled according to the National Institute for Occupational safety and Health (NIOSH), USA protocol. The study reports the higher particulates and respirable silica with respect to the national and international guidelines in and around the study units. However, in nearby villages, the particulate concentrations and silica were comparatively less. An innovative dust abatement dry engineering control system was installed as a pilot work to reduce dust emission from the unit and the results afterward were found to be encouraging.

Objective: The present work entails design and characterization of enteric coated mucoadhesive microcapsules loaded with amoxicillin trihydrate as a novel chronotherapeutic approach for the treatment and management of bacterial infection. Methods:The microcapsules were prepared by solvent evaporation technique using ethyl cellulose (EC) and hydroxypropyl methylcellulose (HPMC) as rate-controlling and mucoadhesive polymers, followed by a triple coating with Eudragit L100 as enteric coating polymer. Box-Behnken statistical design (BBD) was applied for optimization of formulations containing EC, HPMCK100M and Eudragit L100 as factors for selected responses like entrapment efficiency, mucoadhesive property and drug release in 24 h. The optimized microcapsules were also characterized for particle size, drug content, swelling index, mucoadhesive strength, and in vivo antiulcer activity. Results:The optimized microcapsules exhibited good entrapment efficiency, particle size and mucoadhesive property. FT-IR studies revealed that there was no drug-polymer interaction. SEM studies revealed that microcapsules were non-aggregated, spherical in shape and smooth appearance. In vitro, drug release data from microcapsules was fitted to different kinetic models to explain release profiles. The correlation coefficient (r 2 ) value indicated that drug release followed Higuchi model. Analysis of variance (ANOVA) showed a significant difference in the release of drug from all the prepared formulations at P<0.05 level. Accelerated stability study of optimized formulation (F4) up to 6 mo showed there was no change in drug content and release characteristics during storage. Conclusion:Overall, the present study indicated the successful development of mucoadhesive microcapsule.

The present studies discuss about the quality by design (QbD)-based development and evaluation of chronomodulated release drug delivery system of amoxicillin trihydrate for management of bacterial infection. Initially, target product profile was defined and critical quality attributes were earmarked. Risk assessment study was performed for identifying the critical material attributes. Preformulation studies were carried out, and direct compression method was employed for the preparation of bilayer matrix tablets containing a delayed and a sustained release layer for preliminary optimization. Systematic formulation optimization was carried out using central composite design by selecting the concentration of Eudragit-L100 D55 and HPMCK4M. Mathematical modeling was performed and optimized compositions of the polymers were identified from the design space. Moreover, the prepared bilayer tablets were evaluated for various tablet properties including in vitro drug release study, release kinetics evaluation and characterized for FTIR, DSC, XRD, SEM studies, in vitro was-off test, antimicrobial assay and accelerated stability studies. In a nutshell, the present studies indicated the supremacy of designing a chronomodulated release bilayer tablet formulations of amoxicillin trihydrate for effective management of bacterial infections.