In line with the equity market, the Indian rupee dropped further by 13 paise to 44 rupees 90 paise against the US dollar today. This follows persistent dollar demand from banks and importers on the back of a higher dollar in overseas market. The rupee resumed lower at 44 rupees 87 per dollar at the Interbank Foreign Exchange as against yesterday's close of 44 rupees 77 paise per dollar.