Recent Advancements in Microwave Technology in Pharmaceutical Industry
Microwave is apparently heading for exhibiting good potential in the field of Pharmaceutical industry. The write up attempts to throw light on what is microwave, how is it generated and what importance may it have.
The whole 7 pages article is available for download here.
The whole 16 pages article is available for download at Downloads section of Farmavita.Net.
Microwave radiation, an electromagnetic radiation, is widely use as a source of heating in organic synthesis Microwaves have enough momentum to activate reaction mixture to cross energy barrier and complete the reaction. The basic mechanisms observed in microwave assisted synthesis are polarization (mainly dipolar polarization) and conduction. The benefits of microwave synthesis including increasing speed, yield and clear chemistry with decreasing time, have provided the momentum for many chemists to switch from traditional heating method to microwave assisted chemistry. The present paper highlights the current scenario of microwave technology in pharmaceutical sector.
Microwave heating refers the use of electromagnetic waves ranges from 0.01m to 1m wave length of certain frequency to generate heat in the material. These microwaves lie in the region of the electromagnetic spectrum between millimeter wave and radio wave i.e. between I.R and radio wave. Microwave, which has gained recent popularity, has a great potential in pharmaceutical industry. Waves are generally of two types Electromagnetic waves and Mechanical waves. The main point of differentiation is electromagnetic waves do not require a medium for transportation, as required by mechanical waves.1, 2 Microwave is generated in special type of electron tubes. These contain cathode, anode and grid inside an evacuated envelope. For generation of microwaves these should operate at very high frequency range (300 - 3000 MHz). Ordinary electron tubes can operate at frequencies up to about 30 MHz. So the tubes must be designed in a different manner, because the frequency is comparable to the electron transit time (it is the time needed for electrons to travel between electrodes). 3.4.5 Microwave is a type of electromagnetic wave whose wavelength range falls in between Radio waves & Infrared waves as shown in Table
Table: -Range of frequencies of Electromagnetic waves
| TYPE | APPROXIMATE WAVELENGTH RANGE (METERS) | APPROXIMATE FREQUENCY RANGE (HERTZ) |
| RADIO WAVES | 10 - 1000 | 3 X 105 - 3 X 107 |
| TELEVISION WAVES | 1 - 10 | 3 X 107 - 3 X 108 |
| MICRO WAVES | 1 X 10-3 - 1 | 3 X 108 - 3 X 1011 |
| INFRARED | 8 X 10-7 - 1 X 10‑ 3 | 8 X 10-7 - 4 X 1014 |
| VISIBLE LIGHT | 4 X 10-7 - 7 X 10‑ 7 | 4 X 1014 - 7 X 1014 |
| ULTRA VIOLET | 1 X 10-8 - 4 X 10‑ 7 | 7 X 1014 - 3 X 1016 |
| X-RAYS | 5 X 10-12 - 1 X 10‑ 8 | 3 X 1016 - 6 X 1019 |
| GAMMA RAYS | 1 X 10-13 - 5 X 10‑ 12 | 6 X 1019 - 3 X 1021 |
| COSMIC RAYS | Less than 1 X 10-13 | Greater than 3 X 1021 |
The whole 7 pages article is available for download here.