Investigation of goodness for some drugs using laser scattering

In this work a simple setup was built to measure the angular scattering of laser light as an approach for testing the quality of some pharmaceutical solutions and detect any change in its concentration with respect to the standard one suitable for desired dose. A diode laser with wavelength of 671 nm and output power of 100 mW and a photomultiplier tube were used to find the relation between drug concentration and the scattered intensities of the laser beam at angles of 45o, 90o and 135o with respect to the direction of incidence for the samples: Benzylpenicillin sodium (BS), metronidazole and actrapid HM (insulin human) (IH). The results showed that the relation between the angular scattered intensity and sample concentration is linear. The study proved that this setup was very sensitive to detect the change in the scattered laser intensities for any small change in sample concentration from its standard concentration. From the features mentioned above it was clear that this setup was very efficient in discovering any manipulation in the drug concentration.