Gentamicin sulfate is composed of multiple components and is prone to the formation of degradation products. These characteristics determine that the quality control of global chemical gentamicin sulfate must take into account both component homogeneity and purity control. Whether in the production of raw materials or in the processing of preparations, the quality control of gentamicin sulfate is centered on pharmacopoeia standards and achieved through precise testing throughout the process.
The potency determination of global chemical gentamicin sulfate is a fundamental indicator for quality control. Using the microbial assay method and with Escherichia coli as the test strain, the antibacterial activity of gentamicin is measured by the disk diffusion method. The potency must conform to 90.0% - 120.0% of the labeled quantity. This method takes advantage of the characteristic that gentamicin sulfate inhibits bacterial growth. The potency is calculated by measuring the diameter of the inhibition zone, and the results can directly reflect the antibacterial ability of the drug. The determination of potency requires strict control of the pH value of the culture medium, the culture temperature, and time to ensure consistency of the experimental conditions and avoid errors affecting the accuracy of the results.
Component control is the core feature of quality control for global chemical sulfadiazine sulfate. Sulfadiazine sulfate is mainly composed of components such as C1, C1a, and C2. The antibacterial activities and toxicological properties of each component vary, so the pharmacopoeia clearly stipulates the content range of each component. Component analysis is carried out using high-performance liquid chromatography (HPLC), with octadecylsilane bonded silica gel as the stationary phase, a mixed solution of heptanesulfonic acid sodium and acetonitrile as the mobile phase, and combined with an evaporative light scattering detector for detection. The content of each component is calculated using the normalization method to ensure that the content of the main components meets the standards and to avoid affecting the efficacy of the drug due to abnormal component ratios.
The inspection of substances is an important part of the quality control of global chemical sulfadiazine sulfate. During the production and storage of sulfadiazine sulfate, degradation products and intermediate substances related to it are prone to occur. These substances need to be detected by the HPLC method. Using a cation exchange chromatographic column, a potassium dihydrogen phosphate solution is used as the mobile phase, and the pH value is adjusted to an appropriate range to achieve effective separation of the related substances from the main peak. At the same time, the sulfate content in sulfadiazine sulfate needs to be detected by the gravimetric method to ensure that the ratio of sulfate to sulfadiazine conforms to the chemical stoichiometric relationship and avoids the influence of free sulfate on the stability of the drug.
The quality control of the preparations of global chemical gentamicin sulfate requires additional attention to sterility and clarity. For the injectable gentamicin sulfate, sterility test and pyrogen test are required to ensure no microbial contamination and no pyrogen substances. For the oral preparations, the dissolution rate needs to be tested. The paddle method is used with water as the dissolution medium to ensure that the drug can be effectively released in the gastrointestinal tract. For each batch of products, comprehensive quality testing is required, and only those that pass the tests can be released. The strict quality control system provides a guarantee for the clinical application of gentamicin sulfate, enabling it to continue to play a role in anti-infection treatment.