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The objective of the present study was to develop a once-daily sustained-release (SR) matrix tablet of famotidine. Nine different formulations (F1–F9) were prepared by direct compression method using Avicel PH101 as filler/binder in the range of 41–27% in F1–F3, 18–22% in F4–F7, and 16–18% in F8–F9 and hydroxypropyl methylcellulose (4,000 cps) as hydrophilic matrix was used in F1–F3 from 19% to 30%, around 40% in F4–F7, and 42–45% in F8–F9. Talc and Aerosil were added in the ratio of 0.7–1.2%. The tablets were subjected to various physical parameters including weight variation test, hardness, thickness, diameter, friability, and in vitro release studies. Assay was also performed according to the USP 30 NF 25 procedure. The results of the physical parameters and assay were found to be within the acceptable range. In vitro dissolution results indicated that formulation F4–F7, having around 40% of rate control polymer, produced a SR pattern throughout 24 h. F1–F3 showed drug release at a faster rate, while F8–F9 released much slower, i.e.

A hydrophobic solid such as talc, graphite, paraffin, molybdenite, sulfur, high-rank unoxidized coal, etc., does not require a collector for its separation by flotation unless contaminated by polar species so strongly that its surface turns hydrophilic. To improve the kinetics of flotation, a hydrophobic solid does require an addition of a frother-acting dipolar surfactant; occasionally, an addition of a nonpolar oil is also needed to improve the solid’s hydro-phobicity if it becomes partially reduced by contamination.

An automated analysis technique utilizing scanning electron microscopy, energy dispersive x-ray analysis, and image analysis was used to determine the exogenous particulate burdens for 48 urban lung specimens from the Cincinnati, Ohio area. Over 60,000 individual particle analyses were performed for the sample group. The mean exogenous particle concentration was 508 ± 417 × 106 particles per gram of dry lung, with a range of 107 − 1844 × 106 particles/g. The particle compositions found in all lungs were very similar. Major particle types included various aluminum silicates, silica, rutile, iron oxide, talc, and alumina. This data will serve as baseline data for lungs with no overt pneumoconioses against which the particle contents of diseased lungs can be compared.