R 2 is selected from the group consisting of: hydrogen, -CH(R a )OPO(OH)2, -CO-Y, -i-PO(OY) 2 , --PO(OH) 2 , -C(=0)-Y, -CO-U, -C(=0)-(CH 2 )rU, and -CH 2 -V, where R a is hydrogen or CH 3 , where Y is -Z-(CH 2 )q-W-R b , q is 0-4, where Z and W are independently selected from the group consisting of: CH 2 , O, S, R C and R b , where R c is selected from the group consisting of: hydrogen, C1-C4 alkyl, and C 3 -C 6 cycloalkyl, R b is selected from the group consisting of: hydrogen, C1-C12 alkyl, C1-C12 substituted alkyl, C1-C12 alkenyl, C1-C12 substituted alkenyl, C1-C12 alkynyl, C1-C12 substituted alkynyl, C 3 -Cs cycloalkyl, C 3 -Cs substituted cycloalkyl, C 6 -Cio aryl, C 6 -Cio substituted aryl, C 3 -Cs heterocycloalkyl, C 3 -Cs substituted heterocycloalkyl, C4-C10 heteroaryl, and C4-C10 substituted heteroaryl, where r is 0-5, U is selected from aryl, heteroaryl or heterocycloalkyl, where V is -0-C(=0)-Q-(CH 2 )r-R d , where Q is selected from the group consisting of: a bond, O, and N(R C ), where R d is selected from the group consisting of: C6-C10 aryl, C4-C10 heteroaryl, C 3 -Cs heterocycloalkyl, a hexose, a pentose, and - (5-methyl-2-oxo-l,3-dioxol-4-yl)methyl), or alternatively -C(=0)-Y forms an amide bond thru a nitrogen atom on Y in which case Y is a selected from the group consisting of: glycine, sarcosine, ,-diemthyl glycine, alanine, valine, leucine, isoleucine, lysine, ornithine, arigine, serine, and theronine

Ingredients of C Nac Eye Drops 10Ml Carboxymethyl Cellulose (0.3%): It is a key lubricant in C-Nac Eye Drop, known for its ability to mimic natural tears
For patients that desire it, a topical anesthetic can be used
Free fatty acid and tryptophan levels were among the top negative correlates to CRP levels, which were also directly proportional to levels of picolinic acid, inosine, and short-chain acylcarnitines (Figure 7B)