Evaluating human milk as a drug delivery vehicle for clofazimine to premature infants

Human milk improves the oral bioavailability of the poorly water-soluble drug clofazimine

Clofazimine is an emerging drug for the treatment of cryptosporidiosis in infants. As a poorly water-soluble drug, the formulation of clofazimine in age-appropriate vehicles is challenging and often results in the use of off-label formulations. Milk-based vehicles such as human milk and bovine milk have been investigated as age-appropriate formulations and shown to increase the solubilisation of poorly water-soluble drugs via enhanced solubility in lipid digestion products in vitro. We hypothesised that administration of clofazimine within a milk-based vehicle would enhance bioavailability for infant patients. Towards this objective, suspensions of clofazimine in human and bovine milk were orally administered separately to piglets and rats and the subsequent plasma concentrations were compared to those after administration of an aqueous drug suspension. Initial investigations with a rodent model showed a significant increase (258%) in the oral bioavailability of clofazimine when administered with human milk. Similarly, the oral bioavailability of clofazimine was significantly higher when administered in both human (154%) and bovine milk (175%) using a neonatal piglet model, suggesting comparable enhancement in oral bioavailability could be achieved with human or bovine milk. These findings demonstrate the potential of human milk in particular to provide an effective administration vehicle for clofazimine administration to infants without the need for additional excipients.

Pharmacokinetics and Safety of Group A and B Anti-Tuberculosis Drugs Used in Treatment of Rifampicin-Resistant Tuberculosis during Pregnancy and Post-Partum: A Narrative Review

Recommendations for treatment of rifampicin-resistant tuberculosis (RR-TB) during pregnancy and post-partum now include Group A and B antituberculosis drugs. While pharmacokinetic data for most of these drugs among adults receiving treatment for RR-TB are limited, the data from pregnant patients and their infants are extremely scarce. Existing data suggest that fluoroquinolones, bedaquiline, clofazimine and terizidone may be used safely in pregnancy. Pharmacokinetic exposures, particularly between trimesters, are potentially sub-optimal; however, there is currently no evidence to support dose adjustment during pregnancy. Linezolid poses a potentially serious toxicity risk, particularly as exposures appear to be high in the later stages of pregnancy and post-partum following extended use, but this should be considered alongside the benefits of this extremely effective drug in the treatment of this life-threatening disease. While plenty of questions remain regarding the exposure to Group A and B antituberculosis drugs through breastmilk, existing literature suggests minimal harm to the breastfed infant. Pregnant patients and their infants should be included in therapeutic trials and pharmacokinetic studies of effective antituberculosis drugs.