New Delhi, 01 February (NNS): The prices of black pepper slipped by Rs 10 to Rs 645 per kg owing to the sluggish offtake even after the feeble prices. Recently, the prices have gone down in the same ratio. The arrivals reported to be negligible and the prices remained stable at the same level in Kochi. In this situation, the prices may not show more uptrend in the spot black pepper prices during the coming days.