The present invention relates to a compound of the formula (I) or a solvate or co-crystal thereofwherein:- R is selected from the group consisting of: a C1-C6 alkyl, a C2-C8 alkenyl moiety, a C4-C12 dienyl or a C6-C18 trienyl moiety;- R1 is a C1-C6 alkyl moiety;- R2 is selected from the group consisting of: H and a C1-C6 alkyl moiety;- R3 is selected from the group consisting of: H and a C1-C6 alkyl moiety;- R4 is selected from the group consisting of: H, a C1-C6 alkyl moiety and a benzyl moiety. The present invention also relates to a process for producing said compound of the formula (I), or a solvate or co-crystal thereof, as well as a pharmaceutical composition comprising said compound of the formula (I), or a solvate or co-crystal thereof and at least one excipient. The present invention also relates to a compound of the formula (I), or a solvate or co-crystal thereof, for use in the treatment or prevention of a disease or condition.