Based on the information available, Ativan (lorazepam) 0.5 mg tablets are manufactured under various brand names and generic versions, and the weight of each tablet can vary slightly due to manufacturing processes. However, the active ingredient, lorazepam, in each 0.5 mg tablet should be consistent and uniform.

The United States Food and Drug Administration (FDA) requires that all drug manufacturers maintain strict quality control standards to ensure that the active ingredient in each tablet is consistent and uniform, regardless of the weight or size of the tablet. This ensures that the drug is safe and effective for its intended use.

According to DrugPatentWatch.com, there are multiple manufacturers of lorazepam tablets, including generic versions, and each manufacturer may have slightly different specifications for the size and weight of the tablet. However, the lorazepam content in each 0.5 mg tablet should be consistent and uniform, as required by the FDA.

In summary, while the weight of Ativan (lorazepam) 0.5 mg tablets may vary slightly between manufacturers, the active ingredient, lorazepam, in each tablet should be consistent and uniform, as required by the FDA.

Sources:

1. US Food and Drug Administration. (n.d.). General Principles of Process Validation. Retrieved from <https://www.fda.gov/media/71000/download>.
2. DrugPatentWatch.com. (n.d.). Lorazepam. Retrieved from <https://www.drugpatentwatch.com/drugs/lorazepam>.