Rectal Dexmedetomidine Niosomes for Postoperative Analgesia in Pediatric Cancer Patients. (DEX-NANO)

The Population Pharmacokinetics and Pharmacodynamics of Rectal Dexmedetomidine Niosomes Administered for Postoperative Analgesia in Pediatric Cancer Patients.

Applying nanotechnology in drug delivery systems improved the bioavailability and kinetic profile of drugs in biological systems

Nanotechnology which is focused on studying the properties and the applications of materials with structure size in the range of 1-100 nm has been widely used in various fields. In biomedical research fields, nanotechnology has been used to design and development of drug delivery systems (DDSs). Nanotechnology-based drug delivery systems (NDDSs) offer many potential advantages in cancer treatment, such as improving targeting of the therapeutic drugs, protecting drugs from degradation during in vivo transport, controlled drug release at specific sites or cells in response to specific signals, and thus improving the therapeutic efficacy while minimizing side effects. Applying nanotechnology in drug delivery systems improved the bioavailability and kinetic profile of drugs in biological systems. Advances in nanotechnology aid in targeting drugs to specific molecular targets and safely delivering drugs to specific sites of action. The sustained release of nano-drug delivery systems enhances the controlled release profile of loaded drugs, thereby minimizing the dosage-regimen. The aim of this study will be to investigate the population pharmacokinetics and pharmacodynamics of rectal dexmedetomidine Niosomes for Postoperative Analgesia in Pediatric Cancer Patients undergoing bone marrow biopsy and aspiration in comparison with the intravenous and rectal plain formulation.

This study will investigate the population pharmacokinetics and pharmacodynamics of rectal dexmedetomidine Niosomes for Postoperative Analgesia in Pediatric Cancer Patients undergoing bone marrow biopsy and aspiration in comparison with the intravenous and rectal plain formulation.

An independent investigator not involved in the study will open the envelopes 1 h before induction of anesthesia and will prepare the study drug solutions in identical syringes and formulations with matching random codes.

Patients will receive iv DEX 1µ/kg diluted in 100 ml saline and given slowly iv infusion over 10 min. and rectal placebo 30 min. before induction of anesthesia.

Patients will receive rectal DEX suppository formulation at approximately 1µ/kg an iv. saline placebo. at 30 min. before induction of anesthesia.

Patients will receive rectal DEX suppository in the Niosomes formulation at approximately 1µ/kg an iv. saline placebo at 30 min. before induction of anesthesia

patients will receive iv DEX 1µ/kg diluted in 100 ml saline and given slowly iv infusion over 10 min. 30 min. before induction of anesthesia.

Patients will receive rectal DEX suppository formulation at approximately 1µ/kg at 30 min. before induction of anesthesia

Patients will receive rectal DEX suppository in the Niosomes formulation at approximately 1µ/kg at 30 min. before induction of anesthesia

Pharmacokinetic parameters will be determined using noncompartmental method with WinNonlin professional Version 2.1 software (Pharsight Corporation, Mountain View, CA) based on measurement of plasma concentrations of DEX

Inclusion Criteria: ASA physical status I and II. Aged 3-7 yrs. Undergoing bone marrow aspiration and biopsy. Exclusion Criteria: Allergy to the study drugs. Significant organ dysfunction. Cardiac dysrhythmia. Congenital heart disease. Use of psychotropic medication. Mental retardation.