Doxycycline Capsules

Doxycycline is a semisynthetic antibiotic of the tetracycline class derived from oxytetracycline. It is a bacteriostatic agent but can also exhibit bactericidal effects in high concentrations. Doxycycline, like other members of the tetracycline group, has a broad-spectrum activity against a wide range of gram-positive, gram-negative, and atypical organisms. The drug is also active against some protozoan pathogens. Clinically, doxycycline is a drug of choice for the management and treatment of many mild-to-moderate infectious diseases. 123

Doxycycline has immunomodulating and anti-inflammatory properties. It also has shown potential against a range of pathogens resistant to antibiotics. These include ampicillin-susceptible strains of Haemophilus influenzae,4 penicillin-resistant strains of Staphylococcus aureus,56 β-lactamase-producing strains of Moraxella catarrhalis,78 multidrug-resistant strains of Acinetobacter baumannii9 and Stenotrophomonas maltophilia,10 and strains of organisms resistant to other tetracyclines.

Doxycycline has excellent oral availability and a low binding affinity with calcium (Ca2+) ions. Unlike other tetracyclines, however, it is more lipid-soluble and has a prolonged serum half-life. 1112 Doxycycline also has high stability in normal human serum and therapeutic drug monitoring is extremely rare. The drug is available in multiple dosage forms including tablet, capsule, syrup, oral suspension, and reconstituted powder for IV. Doxycycline, along with minocycline, can be administered irrespective of meals. The US-FDA first approved doxycycline in 1967 and currently defines it as a wide therapeutic index drug. 13 It is also included in the List of Essential Medicines by the World Health Organization as a first-choice treatment for sexually transmitted infection caused by Chlamydia trachomatis.