Abstract: Compounds of formula (I) and pharmaceutically acceptable salts thereof: ##STR1## wherein R.sub.1 is hydrogen or hydroxy; andR.sub.2 is C.sub.1-6 alkyl;which are pro-drugs for 9-(3-hydroxyprop-1-oxy)guanine having antiviral activity, a process for their preparation and their use as pharmaceuticals.

Abstract: The invention provides an improvement in the suspension polymerization of vinyl chloride in an aqueous medium in the presence of a monomer-soluble polymerization initiator, according to which the amount of polymer scale deposition on the reactor walls can be greatly decreased. The improvement comprises admixing the aqueous polymerization medium with (a) a water-soluble crosslinked copolymer of an unsaturated carboxylic acid monomer, e.g. acrylic acid, and a crosslinking monomer such as di(methyl)allyl ether of diethyleneglycol and (b) a non-ionic surface active agent in combination.