title: Investigating the effect of Aloe vera gel on the buccal permeability of didanosine.
abstract: The buccal mucosal route offers several advantages but the delivery of certain drugs can be limited by low membrane permeability. This study investigated the buccal permeability properties of didanosine (ddI) and assessed the potential of Aloe vera gel (AVgel) as a novel buccal permeation enhancer. Permeation studies were performed using Franz diffusion cells, and the drug was quantified by UV spectroscopy. Histomorphological evaluations were undertaken using light and transmission electron microscopy. The permeability of ddI was concentration-dependent, and it did not have any adverse effects on the buccal mucosae. A linear relationship (R² = 0.9557) between the concentrations and flux indicated passive diffusion as the mechanism of drug transport. AVgel at concentrations of 0.25 to 2 %w/v enhanced ddI permeability with enhancement ratios from 5.09 (0.25 %w/v) to 11.78 (2 %w/v) but decreased permeability at 4 and 6 %w/v. Ultrastructural analysis of the buccal mucosae treated with phosphate buffer saline pH 7.4 (PBS), ddI/PBS, and ddI/PBS/AVgel 0.5 %w/v showed cells with normal plasmalemma, well-developed cristae, and nuclei with regular nuclear envelopes. However, cells from 1, 2, and 6 %w/v AVgel-treated mucosae showed irregular nuclear outlines, increased intercellular spacing, and plasmalemma crenulations. This study demonstrates the potential of AVgel as a buccal permeation enhancer for ddI to improve anti-HIV and AIDS therapy.
authors.affiliation: School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ojewole
authors.forename: Irene
authors.initials: I
authors.lastname: Mackraj
authors.forename: Kamil
authors.initials: K
authors.lastname: Akhundov
authors.forename: Josias
authors.initials: J
authors.lastname: Hamman
authors.forename: Alvaro
authors.initials: A
authors.lastname: Viljoen
authors.forename: Eugene
authors.initials: E
authors.lastname: Olivier
authors.forename: James
authors.initials: J
authors.lastname: Wesley-Smith
authors.forename: Thirumala
authors.initials: T
authors.lastname: Govender
mesh_terms: D000278:Administration, Buccal; D000504:Aloe / Q000737:chemistry*; D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D016049:Didanosine / Q000493:pharmacokinetics*; D005782:Gels / Q000494:pharmacology; D066298:In Vitro Techniques; D009061:Mouth Mucosa / Q000187:drug effects / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D013552:Swine
chemical_list: D005782:Gels; D010936:Plant Extracts; D016049:Didanosine