CORE Group, the drug delivery company based in Kilmarnock, announced yesterday that one of its re-formulated feminine healthcare products had successfully completed a clinical study and would enter pivotal trials in the UK and US by the middle of this year.

However, it was also revealed that development of another female healthcare product for the treatment of thrush had been discontinued. This product uses the same delivery system as the successful treatment for bacterial vaginosis.

The system developed by Core, known as Hycore-VTM, is aimed at a controlled and cleaner delivery of existing drugs used in feminine healthcare. In the case of the product for thrush, it was determined that Miconazole was not the appropriate drug for use with the Hycore system.

Core chief executive Jim Pickard said there were a number of other drugs that might replace Miconazole in the Hycore treatment for thrush, although a successor has not yet been identified. He added that the company was talking to a few potential partners about the female healthcare range, and the preferred partner was ''aware of the situation, but not concerned''.

In fact, he hopes the successful clinical study for the bacterial vaginosis product will help accelerate negotiations.

Core is in discussions with the US Food and Drug Administration (FDA) about the structure for the next set of clinical trials. Recruitment of patients begins shortly, with the study expected to begin in the middle of the year.

Core's other lead product, the Moraxen morphine pessary to ease pain in terminal cancer patients, is due to be launched later this year. This product will be marketed in conjunction with German group Schwarz Pharma.

The Ayrshire-based company's share price took a serious knock last year when the development timetable for Moraxen and the Hycore treatments were set back.

The company's shares, which floated at 250p in April 1997, have since been on a downward slide to yesterday's closing price of 38.5p.