Preparation and Evaluation of a Powdered Rebamipide Mouthwash as In-Hospital Formulation: Considering Dispersion before Use in Patients

In Japan, rebamipide (RB) mouthwash (RB-MW) for oral mucositis induced by cancer chemotherapy has been prepared using in-hospital formulation. Usually, RB-MW is prepared by dispersing crushed commercial RB tablets in the dispersion medium; however, uniformity is difficult to obtain due to low solubility. The current study aims is to prepare homogenously dispersed formulations using the fine particles of crushed tablets by a method that is convenient for hospital use. Commercial RB tablets were pre-milled at different milling times as “RB-Ts”. A ground mixture was then prepared by co-grinding the RB-Ts with HPC-L or PVP K30 via a benchtop ball milling machine (MM400). The physicochemical properties of samples were evaluated for PXRD, FTIR, turbidity, particle size, and solubility. Although the milling of RB tablets decreased the crystallinity, the length of milling time did not affect them. In contrast, grinding using MM400 significantly decreased RB crystallinity; their PXRD patterns showed a halo, suggesting the amorphization of RB crystals by grinding. Although solubility and turbidity seemed to be affected by the type of polymer rather than the particle size, every ground mixture showed high dispersibility. Thus, grinding the RB-Ts with polymers appeared to be the most promising way to obtain stable dispersion as an in-hospital formulation.

Research of properties of cement-soil piles of foundations of buildings and structures

The review of soil types prevailing in Western Siberia of the Russian Federation is presented. The compositions and physical and mechanical properties of soils are analyzed. Special attention is paid to loess subsidence soils. The problem of obtaining a homogeneous cement-ground mixture is formulated and set. The technological scheme of production of cement-ground piles of foundations of buildings and structures by drilling-mixing method with mechanical activation is considered. Considers methods of strengthening the loess subsidence of soils. Methods for studying the properties of cement-based piles of foundations of buildings and structures are formulated. A multi-factor experiment was conducted to evaluate the parameters that affect the properties of cement-based piles. Based on the research results, conclusions and recommendations are formulated.

Dissolution rate and bioavailability enhancement of co-ground mixtures of paliperidone, with different hydrophilic carriers

Co-ground mixtures of poorly water soluble drug Paliperidone (PAL) with different hydrophilic carriers [Polyvinylpyrrolidine (Plasdone K-25 and Plasdone S-630), Hydroxypropyl methyl cellulose (HPMC), Hydroxypropylcellulose (HPC) and Sodium alginate were prepared to improve the dissolution rate of PAL. Co-grinding with PVP, especially with PVP- S630 (Vinyl pyrrolidone/ vinyl acetate co-polymer), was more effective in reduction of particle size than milling of drug alone. DSC studies indicated that crystalline nature of drug was reduced after co-grinding with PVP grades as compared to their corresponding physical mixtures. The hydrophilic carriers other than PVP did not reduce the crystalline nature of the drug significantly. X-ray diffraction (XRD) was carried out for selected batches to confirm DSC results. Significant enhancement in dissolution rate as well as extent was observed with co-ground mixtures of drug and PVP. Among all the prepared batches in this study, co-ground mixture of PAL and Plasdone S-630 in 1:1 ratio showed best results in terms of extent of dissolution as well as dissolution rate in water. This effect was not only due to particle size reduction, but also loss of crystalline nature of the drug during co-grinding. PVP was found to be a better carrier among the different hydrophilic carriers used in the study for improving the dissolution characteristics of PAL. The extent of the mean plasma exposures of PAL was 7-fold higher in animals treated with co-ground mixture of PAL, Plasdone S630 (1:1) compared to animals treated with Pure PAL.DOI: http://dx.doi.org/10.3329/icpj.v2i3.13632 International Current Pharmaceutical Journal, February 2013, 2(3): 70-77