Oral Metronomic Formulation of Carboplatin Loaded PEGylated- MWCNTs: HPLC Method Validation and Pharmacokinetic Studies in Rabbit’s Plasma

Carboplatin (CP) is a widely used chemotherapeutic agent with poor oral bioavailability and potential systemic toxicity when administered intravenously. There is a growing interest in developing sustained-release oral formulations to improve therapeutic efficacy and patient compliance.

The present study aimed to develop and evaluate an oral, enteric-coated, PEGylated multi-walled carbon nanotube (MWCNT) formulation (F2) of carboplatin and assess its pharmacokinetic and histopathological profile in comparison with the marketed intravenous product, Kemocarb^®.

A sensitive and robust HPLC method was developed for the quantification of CP in rabbit plasma. Stability studies were performed at 4 °C for 4 hours and -80°C for 4 weeks. Histopathological evaluation was conducted on major organs of mice to assess toxicity. CP and caffeine were extracted with minimal matrix interference. Pharmacokinetic studies were performed following oral administration of the F2 formulation and compared with Kemocarb^®.

The developed HPLC method demonstrated good sensitivity, accuracy, and robustness. CP was stable under both short-term and long-term storage conditions. Histological analysis revealed no significant pathological damage in mice organs. The F2 formulation exhibited sustained drug release for up to 24 hours. The Tmax, Cmax, and MRT of CP for F2 were different compared to Kemocarb^®, with a relative bioavailability of 1.182 ± 0.24. The Cmax and MRT of F2 were 12.327 ± 0.03* and 3.5805 ± 0.26 h, respectively.

The developed F2 formulation of carboplatin demonstrates sustained release and improved relative bioavailability following oral administration. It may offer a promising alternative to commercial intravenous CP injections (Kemocarb^®), potentially supporting metronomic chemotherapy strategies with improved patient compliance and reduced systemic toxicity.