Sulfonamides, also known as “sulfa drugs”, derived from sulfanilamide (p-aminobenzenesulfonamide) are used in both veterinary and human medicine. In veterinary medicine they are widely used in farm animal feedstuff and fish cultures for prophylactic and therapeutic purposes. In human medicine they are used to treat systemic infections caused by susceptible organisms. Some members of this class include: sulfathiazole, sulfamethazine (sulfadimidine), sulfamerazine, sulfadiazine, sulfapyridine, sulfabromomethazine, sulfaethoxypyridazine, sulfamethoxypyridazine, sulfadimethoxine and sulfachlorpyridazine. Sulfonamides are effective against Gram-positive and Gram-negative bacteria. Some protozoa, such as coccidians, Toxoplasma species and plasmodia, are generally sensitive. Chlamydia, Nocardia and Actinomyces species are also sensitive.
A common disadvantage in all antimicrobial agents is resistance, which is widespread in many animal and human populations. Resistance to sulfonamides in human medicine has severely restricted clinical usefulness. Emergence of drug resistant strains of bacteria, has led to replacement of drug by other semi-synthetic antibiotics to a large extent. However in the third world countries they are of great value. Sulfonamides are well distributed in all body tissues. High concentrations can be found in bile, cerebrospinal fluid, prostatic fluid and sputum. Sulfonamides are metabolized in the liver but are primarily excreted unchanged in the urine. There are exceptions, however. A large proportion of sulfamethoxime is metabolized by the liver and only thirty percent is excreted unchanged by the kidneys.
Occasionally severe side effects are observed with sulfonamides and potentiated sulfonamides (e.g. with trimethoprim). The sulfonamides can cause hepatic necrosis, serum sickness like syndrome, acute hemolytic anemia, agranulocytosis and Stevens-Johnson syndrome. Hypersensitivity is also very common. Therefore analytical methods for the determination of sulfonamides in pharmaceuticals and biological samples are of great importance.
HPLC methods have been discussed herein. HPLC can provide a valuable tool for generating highly pure preparations for characterizing the antimicrobial activities. In the present review article, column and mobile phase conditions as well as sample preparation issues are taken into consideration. A brief discussion on chemical structure, spectrum of activity and action mechanism of sulfonamides has also been provided. The time frame of papers covered by this review article starts at 1974 and ends at 2009.