Abstract: Siloxy-terminated hydrocarbon polymers containing at least one polymer chain per molecule of the formula: ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are independently selected from saturated and unsaturated aliphatic and aromatic radicals, A is a saturated hydrocarbon bridging group optionally containing at least one aromatic group and --(M)n -- represents a polymer of an olefinic monomer, n having a value such that the average molecular weight of the polymeric chain is from about 1000 to about 5,000,000, together with telechelic polymers and radial polymers containing this unit.

Abstract: An improved transdermal delivery composition is provided comprising a low molecular weight fatty acid, characterised in that it further comprises a long chain fatty acid or a long chain fatty acid lower alkyl ester, wherein the long chain is a C.sub.13 to C.sub.21 chain and preferably contains at least one cis-olefinic bond. Preferred long chain components are oleic acid and ethyl oleate while the preferred low molecular weight fatty acid is propionic acid. The compositions are particularly effective at transdermally delivering physostigmine and its analogues in a stable dosaged manner.