2941.90 - Other:

This HTS category, 2941.90, encompasses antibiotics that are not specifically listed under the preceding subheadings within Chapter 29. It serves as a residual category for antibiotics possessing distinct chemical structures or origins that do not fall into the more defined groups such as penicillins, streptomycins, tetracyclines, chloramphenicol, or erythromycin. The classification here hinges on the absence of the characteristic structures or identifying properties of those specifically enumerated antibiotic groups.

To illustrate the distinction from its sibling categories, 2941.90 covers antibiotics that do not conform to the penicillanic acid structure of penicillins (2941.10), the structural features of streptomycins (2941.20), the characteristic four-ring structure of tetracyclines (2941.30), the unique chemical makeup of chloramphenicol (2941.40), or the macrolide ring of erythromycin (2941.50). Therefore, if an antibiotic does not possess the defining chemical attributes of these commonly classified antibiotics, it will likely be considered under this "Other" category.

The subcategories within 2941.90 further refine the classification of these residual antibiotics. The primary subdivision is between "Natural" (2941.90.10) and "Other." The "Natural" subcategory is intended for antibiotics produced directly by living organisms, without significant synthetic modification. The "Other" subcategory, conversely, would encompass antibiotics that are synthetic, semi-synthetic, or derived from natural sources but have undergone substantial chemical alteration, thereby not fitting the precise definition of "Natural" antibiotics within this HTS framework.