Apocynaceae member- Chennai outskirts

Leaves only but distinctive - ID possible ? - GE04102014-3 : 3 posts by 2 authors. Attachments (1).
Seen in the Chennai outskirts, wild.
This is a slender twining glabrous climber, only the leaves were seen, they have a cordate base very narrow sinus and apex is mucronate.
Veins almost not visible except central, leaves held outward stiffly.
No flowers or fruit in August. Again I'm sorry no better images are available.
Perhaps this Pentatropis, but I have not seen that plant before.
Can it be given an ID to some degree of certainity ?
Thanks for any suggestions
Posted pictures are too small to see any details.
Yes, they are low resolution and blurred.
I thought it is a milkweed climber, (glabrous plant, cordate opposite leaves)
The leaves have a very narrow sinus, thinly leathery and held out at very typical angles like solar panels.
My best guess, Toxocarpus.
But it may not be possible to state definitely.