No abstract

The F-C formulation had the highest retention of betamethasone in the skin and the highest 12-hour and 24-hour permeation of betamethasone through the skin into the receptor fluid.The F-10 formulation had the second highest retention of betamethasone in total skin and relatively low permeation of betamethasone into the receptor fluid (Figure 2).The F-10 formulation had skin layer betamethasone concentrations of 33 ng, 18 ng, and 14 ng in the stratum corneum, epidermis, and dermis, respectively (Figure 1).The skin layer concentrations of the F-C formulation were 37 ng, 43 ng, and 34 ng, and those of the F-A formulation were 5 ng, 17 ng, and 14 ng in the stratum corneum, epidermis, and dermis (Figure 1).

Feasibility studies on division of fixed dose combinations of anti-tubercular drugs: an improvement in the tuberculosis therapy d Drug content was not evaluated for the second part (two-third) of the formulations. e As the dosage units used for analysing ethambutol was different from the other three drugs, the given value is the normalized value as per the mean weight of tablets used for analysis of three drugs. Abbreviations: R, rifampicin; H, isoniazid; Z, pyrazinamide; E, ethambutol hydrochloride.All assay values of components of fixed-dose combinations are with in the limits of USP. All these values are mean n = 5-6.In order to have better clarity and not to further crowd the table, only mean values are given.

Drug release from controlled-release (CR) matrix tablets involves the permeation and diffusion of water through the system. In this study, a new methodology is proposed for the measurement of water permeation and simultaneous drug release from the inert, non-swellable CR matrix tablet of diltiazem (DLT) and a correlation is made between these two processes. Cylindrical matrices were readily prepared by direct compression of pellets obtained by extrusion-spheronization. Water transport was studied using tritiated water (HTO) as a permeant in a Franz-diffusion cell and simultaneously drug release was measured. Further, dissolution was performed on USP XXI/XXII dissolution apparatus I using demineralized water. Matrices showed a steady water-uptake up to 6 h and the steady state for HTO permeation lasting from 6-h to 24-h Flux of water permeated and flux of drug released correlated well. Thus, HTO permeation through the matrix tablet and the proposed methodology can be used as a tool and/or surrogate marker for evaluation of controlled release matrix tablets. This methodology can be coined as "high-throughput" in terms of amount of labor and resources required in comparison to that of dissolution.