title: An improved cryopreservation method for porcine buccal mucosa in ex vivo drug permeation studies using Franz diffusion cells.
abstract: The use of isolated animal models to assess percutaneous absorption of molecules is frequently reported. The porcine buccal mucosa has been proposed as a substitute for the buccal mucosa barrier on ex vivo permeability studies avoiding unnecessary sacrifice of animals. But it is not always easy to obtain fresh buccal mucosa. Consequently, human and porcine buccal mucosa is sometimes frozen and stored in liquid nitrogen, but this procedure is not always feasible. One cheaper and simpler alternative is to freeze the buccal mucosa of freshly slaughtered pigs in a mechanical freezer, using DMSO and albumin as cryoprotective agents. This study compared the ex vivo permeability parameters of propranolol hydrochloride through porcine buccal mucosa using a Franz diffusion cell system and HPLC as detection method. The freezing effects on drug permeability parameters were evaluated. Equally histological studies were performed. Furthermore, the use of the parameter transmucosal water loss (TMWL) as an indicator of the buccal mucosa integrity was evaluated just as transepidermal water loss (TEWL) is utilized for skin integrity. The results showed no difference between fresh and frozen mucosal flux, permeability coefficient or lag time of propranolol. However, statistical significant difference in TMWL between fresh and frozen mucosa was observed.
authors.affiliation: Department of Biopharmacy and Pharmaceutical Technology, School of Pharmacy, University of Barcelona, Barcelona, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Amores
authors.affiliation: Department of Biopharmacy and Pharmaceutical Technology, School of Pharmacy, University of Barcelona, Barcelona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Domenech
authors.affiliation: Department of Biopharmacy and Pharmaceutical Technology, School of Pharmacy, University of Barcelona, Barcelona, Spain.
authors.forename: Helena
authors.initials: H
authors.lastname: Colom
authors.affiliation: Department of Biopharmacy and Pharmaceutical Technology, School of Pharmacy, University of Barcelona, Barcelona, Spain.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Calpena
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Granada, Granada, Spain. Electronic address: beatrizclares@ugr.es.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Clares
authors.affiliation: Animal Facility, Bellvitge Health Sciences Campus, University of Barcelona, Barcelona, Spain.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Gimeno
authors.affiliation: Department of Biopharmacy and Pharmaceutical Technology, School of Pharmacy, University of Barcelona, Barcelona, Spain.
authors.forename: Jacinto
authors.initials: J
authors.lastname: Lauroba
mesh_terms: D000418:Albumins; D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D004058:Diffusion; D004121:Dimethyl Sulfoxide; D005260:Female; D009061:Mouth Mucosa; D010539:Permeability; D011433:Propranolol / Q000378:metabolism; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption; D012965:Sodium Chloride; D013552:Swine
chemical_list: D000418:Albumins; D003451:Cryoprotective Agents; D012965:Sodium Chloride; D011433:Propranolol; D004121:Dimethyl Sulfoxide
keywords: Buccal drug delivery; Cryopreservation; Diffusion; In vitro models; Permeability; Transmucosal water loss