Question { Unimarck Pharma, 10445 }

how many types of stability in pharma or API industry ?

Answer

The type of stability study for API and Pharmaceuticals as
per ICH guideline are as follows.
1) Long term stability study (25°C/60%RH)
2) Intermidiate condition (30°C/65%RH)
3) Accelerated study (40°C/75%RH)
4) Photostabiltiy study
please refer the following link for detail information

http://www.ich.org/products/guidelines/quality/article/quali
ty-guidelines.html

Question { IPCA, 12250 }

What is the difference between Optical rotation and Spcefic
optical rotation

Answer

Optical rotation is the turning of the plane of linearly
polarized light about the direction of motion as the light
travels through certain materials. It means it is only a
measure of degree of polarised light.
But Specific optical rptation is the observed angle of
optical rotation (α) when plane-polarized light is passed
through a sample with a path length of 1 decimeter and a
sample concentration of 1 gram per 1 millilitre
optical rotaion(α)
Specific optical rotation = -------------------
path length in decimeters x C

C = concentration in g/ml

The specific optical rotation is Temperature dependent and
also it depends on wavelength of light used for measurement
Generally the sodium D line is used at 589 nm for
measurement.