Ocular tissue absorption of clindamycin phosphate

Area of Science:

• Ophthalmology
• Pharmacology
• Infectious Diseases

Background:

• Clindamycin phosphate is a semisynthetic antibiotic effective against toxoplasmosis and Gram-positive bacterial infections.
• Ocular penetration and efficacy of antibiotics are crucial for treating eye infections.

Purpose of the Study:

• To evaluate the ocular pharmacokinetics of clindamycin phosphate after intramuscular and subconjunctival administration in pigmented rabbits.
• To determine the safety and efficacy of different clindamycin phosphate dosages for ocular infections.

Main Methods:

• Intramuscular injections of 75 mg/kg clindamycin phosphate were administered to pigmented rabbits.
• Subconjunctival injections of varying doses (15-150 mg) were also performed.
• Ocular tissue and serum drug levels were measured at different time points.
• Corneal and conjunctival tissues were examined for signs of inflammation or edema.

Main Results:

• High concentrations of clindamycin phosphate were found in the choroid, iris, and retina following intramuscular injection.
• Adequate drug levels for ocular infection control were maintained in ocular tissues for 24 hours post-injection.
• Subconjunctival injection resulted in sustained high ocular levels, but higher doses (150 mg) caused corneal edema and conjunctival inflammation.
• Lower subconjunctival doses (15-35 mg) achieved therapeutic ocular levels without adverse effects.

Conclusions:

• Clindamycin phosphate demonstrates excellent penetration into ocular tissues after intramuscular administration.
• Subconjunctival administration is a viable route for achieving high ocular drug levels, with careful dose selection necessary to avoid toxicity.
• Clindamycin phosphate holds potential for treating ocular infections, particularly toxoplasmosis and Gram-positive bacterial infections.