Chlortetracycline ointment

Chlortetracycline ointment Diol Heat and shake with hexane. 

Chlortetracycline ointment (1%) is indicated for conjunctivitis or keratoconjunctivitis where Chlamydia or Mycoplasma spp. are the suspected primary pathogens. Topical chloramphenicol is reported to be effective against clostridial infections of the cornea (Rebhun et al 1999). 

Oral and parenteral forms of chlortetracycline are no lunger used because of the poor bioavailabillty and inferiu pharmacokinetic properties of the drug. It is still marketed in ointment forms for topical and ophthalmic use. 

The extraction of chlortetracycline-HCl (Fig. 5.12) from ointment involves the use of a diol column and sorption from hexane. The mechanism of interaction involves the hydrogen bonding of the antibiotic to the hydroxyl groups of the diol. 

Figure 5.12. Structure of chlortetracycline-HCl extracted from ointment.

Bakerbond Application Note PH-037 Extraction of Chlortetracycline HCl from Ointment (See Suggested Reading, Chapter 1). 

Contact allergy to tetracyclines appears to be rare. Aureomycin ointment (Lederle) produced a dermatitis in a woman who applied the ointment to an area treated by dermabrasion. The patient was positive to chlortetracycline and di-methylchlortetracycline, but negative to oxytetracycline, tetracycline, and cymety-cline (Calnan 1967). Bojs and Moller (1974) reported three patients with contact allergy to oxytetracycline. Cross-sensitivity to tetracyclin and methacycline was demonstrated in two of the cases. 

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