International Journal of Pharmaceutics 242 (2002) 129 – 136 Quantification of the bioadhesive properties of protein-coated PVM/MA nanoparticles P. Arbo ´s a , M.A. Arangoa a , M.A. Campanero b , J.M. Irache a, * a Centro Gale ´nico, Uniersidad de Naarra, Apartado 177, 31080 Pamplona, Spain b Sericio de Farmacologı ´a Clı ´nica, Clinica Uniersitaria de Naarra, 31080 Pamplona, Spain Received 8 January 2002; accepted 15 January 2002 Abstract This work describes the bioadhesive properties of poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA) nanoparticles fluorescently-labelled with rhodamine B isothiocyanate, and coated with either Sambucus nigra lectin (SNA-NP) or bovine serum albumin (BSA-NP). The different formulations (10 mg) were administered to animals by the oral route and the fraction of adhered particles to the mucosa was estimated by measuring the fluorescent marker after the digestion of the tissue. Plotting the amount of adhered particles in the whole gut versus time enabled us to determine the affinity of the formulation for the biological support (expressed as Q max ), the intensity and relative duration of the bioadhesive phenomenon (AUC adh and MRT adh , respectively), and the elimination rate of the adhered particles (k adh ). SNA-NP displayed a similar adhesive affinity and adhesive intensity for the gut mucosa than the control particles; although, its maximum of interaction with the mucosa was observed 1 h post-administration, whereas control and BSA-NP took place only 30 min post-administration. On the other hand, the coating of nanoparticles with SNA significantly reduced the k adh (P 0.01) and, thus, MRT adh was 35 min longer for the lectin-conjugate than for the control. BSA-NP displayed a highest initial affinity for the gut mucosa and AUC adh was calculated to be 1.5 fold higher than for the control or SNA-NP. However, BSA-NP were eliminated more rapidly from the mucosa than SNA-NP and, thus, the MRT adh was only 27 min longer than control. In summary, the parameters describing the bioadhesive profile of a given formulation may be useful to quantify the potential of colloidal particulates to interact with a mucosa and to evaluate the influence of different ligands on the bioadhesive properties of the resulting drug carriers. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Nanoparticles; Poly(methyl vinyl ether-co-maleic anhydride); Bioadhesion; Conjugates; Sambucus nigra lectin; Bovine serum albumin www.elsevier.com/locate/ijpharm 1. Introduction The oral route is one of the preferred ways for drug delivery. However, a large amount of drugs remain poorly available when administered by this route. Among other reasons, this fact can be * Corresponding author. Tel.: +33-948-425-600x6313; fax: +33-948-425-649 E-mail address: jmirache@unav.es (J.M. Irache). 0378-5173/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved. PII:S0378-5173(02)00182-5