title: Role of humic acid on oral drug delivery of an antiepileptic drug.
abstract: BACKGROUND
  Humic acid (HA) is omnipresent in natural organic matter that is a macromolecular, negatively charged polyelectrolyte that contains a hydrophobic core. It is also present in a significant amount in Shilajit (used frequently in traditional medicines), which is used in this study as a source of extraction. HA is evaluated for the oral drug delivery of carbamazepine (CBZ).
  
  
  OBJECTIVE
  HA is used in this study to increase the dissolution, intestinal permeation, and pharmacodynamic response of CBZ (bio pharmaceutics classification system (BCS) II) by the technique of complexation and other related mechanism reported with humic substances.
  
  
  METHODS
  Different complexation techniques were explored in this study for the entrapment of CBZ, which was authenticated by molecular modeling and conformational analysis. These were further characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Solubility analysis and dissolution release profile were carried out to access the in vitro parameters. For ex vivo studies, rat gut intestinal permeability was done. And finally pharmacodynamic evaluation (maximal electroshock method) was carried out for optimized complexes.
  
  
  RESULTS
  Molecular modeling approach and instrumental analysis (DSC, XRD, and FT-IR) confirmed the entrapment of CBZ inside the complexing agent. Increased solubility (∼1742%), sustained release (∼78%), better permeability (∼3.5 times), and enhanced pharmacodynamic responses conferred the best to 1:2 freeze dried (FD) and then 1:2 kneading (KD) complexes compared with pure CBZ.
  
  
  CONCLUSIONS
  Now it could be concluded that HA may be tried as a complexing agent for antiepileptic drug and other classes of low water-soluble drug.
authors.affiliation: Department of Pharmaceutics, Jamia Hamdard, New Delhi, India.
authors.forename: Mohd Aamir
authors.initials: MA
authors.lastname: Mirza
authors.forename: Suraj Prakash
authors.initials: SP
authors.lastname: Agarwal
authors.forename: Md Akhlaquer
authors.initials: MA
authors.lastname: Rahman
authors.forename: Abdur
authors.initials: A
authors.lastname: Rauf
authors.forename: Niyaz
authors.initials: N
authors.lastname: Ahmad
authors.forename: Aftab
authors.initials: A
authors.lastname: Alam
authors.forename: Zeenat
authors.initials: Z
authors.lastname: Iqbal
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000927:Anticonvulsants / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D002220:Carbamazepine / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D004304:Dosage Forms; D004337:Drug Carriers / Q000737:chemistry; D004339:Drug Compounding; D016503:Drug Delivery Systems; D005612:Freeze Drying; D006812:Humic Substances; D007583:Jejunum / Q000378:metabolism; D008968:Molecular Conformation; D010539:Permeability; D051381:Rats; D012995:Solubility
chemical_list: D000927:Anticonvulsants; D004304:Dosage Forms; D004337:Drug Carriers; D006812:Humic Substances; D002220:Carbamazepine