Hanmi Pharma_한미약품(CEOs Woo Jong-soo_우종수 and Kwon Se-chang_권세창) has grabbed another opportunity to preempt global generic market with its patent-evading strategy.

The company said it released Vesigeum last week, a generic drug that evaded the salt patent of solifenasin, a compound to treat overactive bladder. The original drug whose salt patent was avoided by Hanmi is Vesicare developed by Astellas Pharma. Vesicare is effective to cure overactive bladder symptoms such as urge incontinence, urinary frequency, and urgency.

The Korean drugmaker managed to evade the salt patent, by changing solifenasin succinate, the main compound of Vesicare, to tartrate. That allowed Hanmi to release Vesigeum, three months ahead of other generic drugs, and at prices about 30 percent lower than those of original medicine.

Solifenasin is the anticholinergic substance that controls detrusor contraction by selectively working for the M3 receptor in a bladder. Because it has high selectivity to the receptor compared with other anticholinergic compounds, its side effects, including dry mouth, are weaker. And its duration of treatment is longer than others because patients show high satisfaction with its efficacy and drug tolerance.

The standard dose of Vesigeum for adults is one tablet once a day regardless of meals, and it is released in two volumes -- 5.33 mg and 10.66 mg.