Quality Criteria and Properties of Magnetic Rectal Suppositories
At present, the high efficacy and prospects of using the energetic and biotropic properties of magnetic fields and the synergetic action of magnetic fields and medicinal preparations are recognized [1 – 3]. The biotropic properties of magnetic fields are manifested by their antiiflammatory, analgesic, and hypotensive effects and by the positive influence upon hemostasis, metabolism, and regeneration of damaged tissues. These properties are now widely employed in cardiology, surgery, traumatology, dentistry, and other fields of medicine. Recent developments, already tested in vivo, include some new applications such as magnetic fluids, emulsions, and rheological suspensions, magnetic microcapsules and plasters, as well as magnetic rectal capsules and suppositories. In these systems, the magnetic components (fillers) – carriers and sources of the curative constant magnetic field – have the form of finely dispersed powders of ferromagnetic compounds, usually barium ferrite and magnetite. The safety of finely dispersed barium ferrite and magnetite powders was demonstrated in [1, 2]. The magnetic remedies, for example – magnetic rectal suppositories (MRS), may either contain a drug component or not. The curative effect of a drug entering into MRS is usually enhanced under the action of its constant magnetic field. Despite the obvious success in the study and practical use of magnetic remedies, these products are as yet not provided with exhaustively developed and strictly formulated quality criteria and, hence, not included into pharmacopoeias. Complete normative documentation for these products is not available either. This circumstance hinders the wide use of magnetic remedies in practice. In this paper, we will make an attempt at analyzing, systematizing, and formulating criteria for the quality control of magnetic rectal suppositoria – a highly promising and rather thoroughly studied type of magnetic medicinal remedies – based on the results of our investigations [1 – 14]. According to the classification of magnetic substances [15], barium ferrite belongs to the group of ferromagnetic substances possessing high magnetism, coercive force, and remanent (residual) magnetization, which is a measure of the biotropic properties of a magnetic field. In developing MRS, it is necessary to solve the following tasks: select the magnetic filler, base suppository substance, and drug component; study the compatibility of these components and the stability of their composition; and determine the value of magnetic induction at the MRS surface. In addition, it is necessary to develop methods and techniques for assessing the properties of MRS from the standpoint of both the traditional suppository characteristics and their special magnetic properties. Finally, it is necessary to develop methods for the qualitative and quantitative analysis of MRS components and to characterize MRS with respect to toxicity, microbiological cleanness, and curing effect. Previously [1 – 3], we have studied the properties of finely dispersed magnetic materials used for the fabrication of MRS and developed physicochemical principles for using these materials in pharmacy. MRS have been successfully tested on a limited number of volunteers in several clinics [1 – 3, 12 – 14]. Barium Ferrite as a MRS Component The quality criteria for finely dispersed powder of barium ferrite BaO 6Fe 2 O 3 were formulated in [1 – 3]. MRS can employ domestic commercial products conforming to State Standards (TU 6-09-1457-67 and TU 6-09-27-254-89). The optimum magnetic properties of barium ferrite powder correspond to the composition BaO nFe 2 O 3 with n = 5.50 – 5.75. The n value can be determined either from the results of chemical analyses or from the Mössbauer data Pharmaceutical Chemistry Journal Vol. 34, No. 10, 2000
The classification and modern use of magnetic dosage forms in medicine
Currently, quite a large variety of magnetic therapy products, including magnetic dosage forms (MDF), is used in medicine. MDF contain different magnetic materials. MDF either contain or do not contain medicinal substances (MS) in their composition. The therapeutic action of MDF is produced by either a biotropic effect of magnetic field (MF) in case MDF is a source of permanent magnetic field, or mechanic action of MDF based on their interaction with an external source of MF, or a combination of the biotropic and mechanic actions. MDF used in medicine have been reviewed, and their classification by magnetic filler type has been provided.
A model for predicting heat transfer through gypsum‐board/wood‐stud walls exposed to fire
To facilitate the development of cost-effective and flexible design options there is a need to develop models to predict the fire resistance of wood-frame building assemblies. Such assemblies often derive much of their fire resistance from a protective membrane composed of gypsum board. A simple two-dimensional computer model is presented to predict heat transfer through gypsum-board/wood-stud walls exposed to fire. Input data for the thermophysical properties of gypsum board were measured exploying standard bench-scale tests. Input data for wood were selected from the literature. Small-and full-scale fire resistance tests were conducted on gypsum-board/wood-stud wall assemblies to provide data for the validation of the model. The model is shown to predict heat transfer through these walls rather well.