| Sr No. | Test | Specification | Result | ||||||
| 1 | Appearance | A white or almost white crystalline powder | White crystalline powder | ||||||
| 2 | Solubility | As per BP 2016 | Complies | ||||||
| 3 | Identification | ||||||||
| a) Melting point | 1690C – 1720C | 1710C | |||||||
| b) IR | The infrared absorption spectrum of sample | Positive | |||||||
| is concordant with the spectrum of | |||||||||
| Sulfamethoxazole CRS | |||||||||
| c) TLC | As per BP 2016 | Complies | |||||||
| d) Chemical test | Should give the positive reaction of primary aromatic amines | Complies | |||||||
| 4 | Appearance of solution | ||||||||
| a) Clarity of solution | Not more than 3.0 NTU | 1.1 NTU | |||||||
| b) Colour of solution | Not more intensely coloured than reference | Complies | |||||||
| solution Y5,BY5 or GY5 | |||||||||
| 5 | Acidity | Not more than 0.30 ml of 0.1 M sodium hydroxide solution | 0.17 ml | ||||||
| 6 | Related substances by HPLC | ||||||||
| Impurity A (Acetyl SMX) | Not more than 0.100 % | Below Disregard Limit | |||||||
| Impurity B (Sulfanilyl SMX ) | Not more than 0.100 % | 0.04% | |||||||
| Impurity C (Isoxamine) | Not more than 0.100 % | Below Disregard Limit | |||||||
| Impurity D (Sulfanilic acid) | Not more than 0.100 % | Below Disregard Limit | |||||||
| Impurity E (Sulfanilamide) | Not more than 0.100 % | Below Disregard Limit | |||||||
| Impurity F ( Isomeric SMX) | Not more than 0.100 % | Below Disregard Limit | |||||||
| Any other impurity | |||||||||
| Unknown Impurity – I | Not more than 0.100 % | Below Disregard Limit | |||||||
| Unknown Impurity – II | Not more than 0.100 % | Below Disregard Limit | |||||||
| Total impurity | Not more than 0.300 % | 0.07% | |||||||
| 7 | Heavy metals | Maximum 20 ppm | Less than 20 ppm | ||||||
| 8 | Loss on Drying | Maximum 0.50 % w/w | 0.30 % w/w | ||||||
| 9 | Sulphated ash | Maximum 0.10 % w/w | 0.04 % w/w | ||||||
| 10 | Assay | Not less than 99.0 % and not more than | 100.2 % w/w | ||||||
| 101.0 % calculated with reference to the | |||||||||
| dried substance | |||||||||
| 11 | Additional test | ||||||||
| a) Sieve test | ———— | 99.8 % < 90 microns | |||||||
| b) Bulk density | ————- | ||||||||
| c) Related substances by TLC | Not more than 0.5 % each | Less than 0.5 % | |||||||