title: Capsule shell material impacts the in vitro disintegration and dissolution behaviour of a green tea extract.
abstract: OBJECTIVE
  In vitro disintegration and dissolution are routine methods used to assess the performance and quality of oral dosage forms. The purpose of the current work was to determine the potential for interaction between capsule shell material and a green tea extract and the impact it can have on the release.
  
  
  METHODS
  A green tea extract was formulated into simple powder-in-capsule formulations of which the capsule shell material was either of gelatin or HPMC origin. The disintegration times were determined together with the dissolution profiles in compendial and biorelevant media.
  
  
  RESULTS
  All formulations disintegrated within 30 min, meeting the USP criteria for botanical formulations. An immediate release dissolution profile was achieved for gelatin capsules in all media but not for the specified HPMC formulations. Dissolution release was especially impaired for HPMCgell at pH 1.2 and for both HPMC formulations in FeSSIF media suggesting the potential for food interactions.
  
  
  CONCLUSIONS
  The delayed release from studied HPMC capsule materials is likely attributed to an interaction between the catechins, the major constituents of the green tea extract, and the capsule shell material. An assessment of in vitro dissolution is recommended prior to the release of a dietary supplement or clinical trial investigational product to ensure efficacy.
authors.affiliation: Unilever Research & Development, Vlaardingen, The Netherlands.
authors.forename: Natalie
authors.initials: N
authors.lastname: Glube
authors.affiliation: Unilever Research & Development, Vlaardingen, The Netherlands.
authors.forename: Lea von
authors.initials: Lv
authors.lastname: Moos
authors.affiliation: Unilever Research & Development, Vlaardingen, The Netherlands.
authors.forename: Guus
authors.initials: G
authors.lastname: Duchateau
keywords: BA, bioavailability; BCS, biopharmaceutical classification system; C, catechin; DS, dietary supplement; Disintegration; EC, epicatechin; ECG, epicatechin gallate; EGC, epigallocatechin; EGCG, epigallocatechin gallate; FaSSIF, fasted state simulated intestinal fluid; FeSSIF, fed state simulated intestinal fluid; Formulation; GA, gallic acid; GTE, green tea extract; Green tea extract; HPMC, hydroxypropyl methylcellulose; HPMCcarr, hydroxypropyl methylcellulose containing carrageenan; HPMCgell, hydroxypropyl methylcellulose containing gellan gum; Hard shell capsule; IR, immediate release; In vitro dissolution; PIC, powder-in-capsule; SIF, simulated intestinal fluid; USP, United States Pharmacopeia