You will be shown a paragraph from a biomedical research article. Your task is to extract all drug combinations appearing in a specific sentence within in the paragraph. Each drug combination should be assigned to one of the following three categories:

- POS: Indicates a positive interaction between the drugs in the combination; for instance, drugs that have an additive or synergistic effect.
- NEG: Indicates a negative interaction between the drugs in the combination; for instance, combining these drugs might result in adverse side effects, or might reduce their efficacy.
- COMB: Indicates that the drugs are given in combination, but the type of interaction between the drugs cannot be determined based on the provided context.

Please format your answer as a json array. Each entry in the array should itself be an array formatted as [<drug_1>, <drug_2>, ..., <drug_n>, <category>] where <category> is one of the three categories listed above and <drug_1>, ..., <drug_n> are drug names copied verbatim from the input sentence. Different combinations may involve different numbers of drugs; in other words, the `n` in <drug_n> may vary.

As an example, the following output describes two extracted drug combinations; one between two drugs, and one between three drugs:

[["artesunate", "artemether", "COMB"], ["Nifedipine", "Labetalol", "Prazosin", "POS"]]

The paragraph and specific sentence are below. You should only extract relationships expressed in the specific sentence; the paragraph is provided for context.

In your output, return only the json array and no other text. If no drug combinations appear, return an empty array `[]`.

paragraph: A liquid chromatographic method for simultaneous determination of amoxicillin sodium and sulbactam sodium in a combination formulation.  An isocratic liquid chromatographic method with UV detection at 210 nm is described for simultaneous determination of amoxicillin sodium and sulbactam sodium in a new combination formulation . Chromatographic separation of the two drugs was achieved on a Hypersil C(18) column using a mobile phase consisting of a binary mixture of methanol and 0.01mol/l sodium acetate (5:95, v/v). The commonly used paired-ion aqueous mobile phase for the determination of penicillins was avoided in this study. The developed LC method offers symmetric peak shape, good resolution and reasonable retention time for both drugs. Linearity, accuracy and precision were found to be acceptable over the concentration ranges of 155.3-1553.0microg/ml for amoxicillin sodium and 45.0-450.0microg/ml for sulbactam sodium. The proposed LC method can be used for the quality control of formulated products containing these two drugs.

sentence: An isocratic liquid chromatographic method with UV detection at 210 nm is described for simultaneous determination of amoxicillin sodium and sulbactam sodium in a new combination formulation .
[]