Penicillinase resistant penicillins

penicillin - Synthesis and Drug Profile

Penicillinase resistant penicillins

i. Methicillin

Synthesis

Properties and uses: Methicillin sodium is a white crystalline solid, odourless, soluble in water, slightly soluble in chloroform, but insoluble in ether. It is particularly resistant to inactivation by the penicillinase found in Staphylococci and somewhat more resistant than penicillin G to penicillinase from Bacillus cereus. Methicillin sodium has been introduced for use in the treatment of Staphylococci infections caused by the strains resistant to other penicillins. It is given by IM or by slow IV infusion every 4–6 h.

ii. Oxacillins (Isoxazolyl penicillins)

Properties and uses: Oxacillin sodium monohydrate is a white powder, soluble in water and methanol, insoluble in methylene chloride. The use of oxacillin and other isoxazolyl penicillins should be restricted to the treatment of infections caused by Staphylococci that are resistant to penicillin G, although their spectrum of activity is similar to that of penicillin G.

Synthesis

Assay: It is assayed by adopting liquid chromatography technique.