title: [Preparation of citrulline microspheres by spray drying technique for colonic targeting].
abstract: BACKGROUND
  Citrulline is an amino acid that becomes essential in situations of intestinal insufficiency such as short bowel syndrome. It is therefore interesting to provide the patients with dosage forms for routing citrulline to the colon. The aim of this work is to formulate microspheres of citrulline for colonic targeting by the technique of spray drying.
  
  
  METHODS
  Eudragit(®) FS 30D was selected as polymer to encapsulate citrulline using the spray drying technique. Citrulline and Eudragit(®) FS 30D were dissolved in water and ethanol, respectively. The aqueous and the ethanolic solutions were then mixed in 1:2 (v/v) ratio. Microspheres were obtained by nebulizing the citrulline-Eudragit(®) FS 30D solution using a Mini spray dryer equipped with a 0.7mm nozzle. The microspheres have been formulated using citrulline and Eudragit(®) FS 30D. The size distribution of microspheres was determined by light diffraction. The morphology of the microspheres was studied by electron microscopy. Manufacturing yields, encapsulation rate and dissolution profiles were also studied.
  
  
  CONCLUSIONS
  The microspheres obtained had a spherical shape with a smooth surface and a homogeneous size except for the microspheres containing the highest concentration of polymer (90 %). The formulation showed that the size and morphology of the microspheres are influenced by the polymer concentration. Manufacturing yields were about 51 % but encapsulation rate were always very high (above 90 %). The in vitro dissolution study showed that the use of the Eudragit(®) FS 30D under these conditions is not appropriate to change the dissolution profile of the citrulline.
  
  
  CONCLUSIONS
  This technique has led to the formulation of microspheres with good physical properties in terms of morphology and size. The compression of the microspheres should help to control citrulline release for colonic targeting.
authors.affiliation: Laboratoire de pharmacie galénique, faculté de pharmacie de Monastir, université de Monastir, rue Avicenne, 5000 Monastir, Tunisie; Unité de préparations stériles, service pharmacie, centre de maternité et de néonatologie de Tunis, rue Jbel Lakhdhar, Bab Saadoun, Tunis, Tunisie. Electronic address: sendabahri@hotmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Bahri
authors.affiliation: Laboratoire de pharmacie galénique, faculté des sciences pharmaceutiques et biologiques Paris Descartes, université Paris Descartes, 4, avenue de l'Observatoire, 75006 Paris, France.
authors.forename: N
authors.initials: N
authors.lastname: Zerrouk
authors.affiliation: Laboratoire de pharmacie galénique, faculté de pharmacie de Monastir, université de Monastir, rue Avicenne, 5000 Monastir, Tunisie.
authors.forename: M-A
authors.initials: MA
authors.lastname: Lassoued
authors.affiliation: Laboratoire de pharmacie galénique, UMR CNRS 8612, faculté de pharmacie Châtenay-Malabry, université Paris-Sud, 5, rue J.B.-Clément, 92296 Châtenay-Malabry, France.
authors.forename: N
authors.initials: N
authors.lastname: Tsapis
authors.affiliation: Laboratoire de pharmacie galénique, faculté des sciences pharmaceutiques et biologiques Paris Descartes, université Paris Descartes, 4, avenue de l'Observatoire, 75006 Paris, France.
authors.forename: J-C
authors.initials: JC
authors.lastname: Chaumeil
authors.affiliation: Laboratoire de pharmacie galénique, faculté de pharmacie de Monastir, université de Monastir, rue Avicenne, 5000 Monastir, Tunisie.
authors.forename: S
authors.initials: S
authors.lastname: Sfar
mesh_terms: D002626:Chemistry, Pharmaceutical; D002956:Citrulline / Q000008:administration & dosage*; D003106:Colon / Q000187:drug effects*; D003890:Desiccation; D004339:Drug Compounding; D016503:Drug Delivery Systems / Q000379:methods*; D005079:Excipients; D006801:Humans; D008863:Microspheres; D010316:Particle Size
chemical_list: D005079:Excipients; D002956:Citrulline
keywords: Ciblage colique; Citrulline; Colonic targeting; Formulation; Microspheres; Microsphère; Spray drying