The invention relates to compounds of Formula ,wherein ring A, X, n, R2, R3, R4, R4\u2032, R5, n, and p are as described in the description; to pharmaceutically acceptable salts thereof, and to the use of such compounds as medicaments, especially as modulators of the CXCR3 receptor. The block has top and bottom surfaces that contain a cooperating projection and slot for stacking the blocks. In a preferred embodiment, tetrapyrrole derivatives such as porphyrins, chlorins and bacteriochlorins, are the preferred hydrophobic photosensitizers to be formulated in calcium phosphate nanoparticle formulations for photodynamic tumor therapy. Finally, the circuit has a MOS transistor located in the second well, spaced from the contact region, and having source, gate and drain regions at the surface. The dispersant is present in the slurry in an amount sufficient to stabilize the slurry at a pH of up to about 10, and has the general formula HxNyOHz, where x has a value of 0, 1 or 2, y has a value of 1 to 8, and z=3\u2212x.