Practical method for choosing diluent that ensures the best temperature uniformity in the case of pharmaceutical microwave vacuum drying of a heat sensitive product.

Microwave vacuum drying is getting more and more popular thanks to its known advantageous and unique features, but its non-uniform electric field can cause nonhomogeneous temperature distribution in the workload. The origin and effect of a generated hot-spot is influenced by the electromagnetic and thermodynamic features of the microwave system and the workload. In the case of single/one pot technology, the geometry and the construction of the microwave cavity is primarily designed for high-shear granulation. As for the workload, its composition has first-order effect on the electric field pattern. The aim of our study is to present a rational decision procedure based on basic practical experiments and the elaborated '3D layered thermography' technique to make it possible to choose the most suitable diluent to formulate a heat sensitive active pharmaceutical ingredient given its stability due to temperature distribution within the workload. Comparing two commonly used diluents, namely microcrystalline cellulose and corn starch, it was found that in the case of different actives with different acceptable temperature limits different diluents are recommended. Drying of a composition consists of an active ingredient characterized by a temperature limit of 70 degrees C. Using corn starch is safer when the workload is less endangered than when using microcrystalline cellulose. Above this temperature limit microcrystalline cellulose becomes beneficial.

[Monitoring the temperature distribution during dielectric drying]. / Mikrohullámú vákuumszárítás során kialakuló hoeloszlás követésének lehetosége.

Microwave assisted vacuum drying offers never questioned advantageous and it is getting more and more popular lately. In spite of its uniqueness there is a rightful resistance and mistrust because the temperature distribution of the workload is far from being homogeneous as a result of the existing inhomogeneous electromagnetic field. The aim of this study is to survey the heat thus field distribution in the workload to prevent local overheating that endangers the quality of the pharmaceutical product. Thermography as a non perturbing thermometrical method was used to map the heat distribution in the workload. To get a 3D information Teflon layers were used to form cross-sectional and photogenic surfaces about the dusty blend and a purpose-developed software to evaluate qualitatively the IR pictures.

[Benefit of microwaves in case of heat-sensitive agglomerate drying]. / A mikrohullám alkalmazásának elónye hóérzékeny agglomerátumok szárítása esetén.

The microwave assisted vacuum drying of heat-sensitive materials is increasing in the pharmaceutical industry since the eighties. This paper deals with results of two experiment series obtained on a laboratory scale single pot dryer (Collette Ultima 251). Firstly water was heated up to the boiling point exclusively by predetermined microwave energy and then by various wall temperatures in order to determine the convection efficiency of the system. The experiments were carried out at fixed pressure level (80 mbar) and with optimum bowl load (15 kg). According to the demonstrated idea each single pot system efficiency can be specified at any type and quantity of load. With the help of the presented results the second experiments were designed to compare the microwave and convection efficiency of the single pot system during granule drying. A placebo granule was dried either by an exclusive convection or microwave method up to the determined LOD (< 0.5%). According to the tests extreme high wall temperature (85 degrees C) had to be used to achieve the same drying time--and efficiency--as with the usage of dielectric heating. Based on the results it can be stated that the shorter drying time under favourable conditions is the advantage of microwave radiation over the conventional technique.

[The generic Research and Development possibilities after Hungary accessed th European Patent Convention]. / A magyar generikus készítményfejlesztés lehetósége az iparjogvédelem tükrében.

January 1, 2003 Hungary became a member of the Munich Convention on the Grant of European Patents (European Patent Convention, EPC). As from January 1, 2003 European patents may be claimed and obtained also for Hungary and European applications may be filed with the Hungarian Patent Office as well. This paper focuses on the exceptional generic R&D possibilities which can harmonize in harmony with all the claims of the Union in spite of the fact that it does not follow general European limitations and practises. Based on the amended Hungarian Patent Law (No. XXXIII of 1995 on the Protection of Inventions by Patents; Article 19 (6)b)) the exclusive right of exploitation shall not extend to acts done for experimental purposes relating to the subject matter of the invention, including experiments and tests necessary for the registration of medicines as well. The national and international legal history and background of the operative Hungarian Patent Law are also presented roughly. The paper deals with the divergence of the originator-generic industry and the EU-USA industry and with the incoherence within the EU itself on the early testing permissions and limitations.