Establishing bioequivalence of veterinary premixes (Type A medicated articles).

a) Key issues concerning Premix (Type A medicated articles) Bioequivalence evaluations: 1) This is a complex issue concerning both route of administration and formulation. 2) If the animal is not at the bunk/trough, the animal is not self-administering (eating medicated feed), thus there can be no drug absorption. b) Differing opinions among scientists and regulatory authorities/expert bodies regarding: 1) No harmonization on how to design, conduct, and interpret in vivo studies. 2) Applicability of biowaivers to Type A (premix) products. 3) Why are topdress and complete feed considered differently? Are they different formulations or different routes of administration? 4) Single dose vs. multi-dose studies. 5) What is the final formulation? c) What are the next steps: 1) Harmonize current bioequivalence guidelines through the VICH process. 2) Determine the applicability/non-applicability of the Biopharmaceutical Classification System (BCS). 3) Establish the Total Mixed Ration (i.e. formulation) effects. 4) Define the test subject (individual, pen, etc.).

[1]  A. Borobia,et al.  Acceptability and characteristics of 124 human bioequivalence studies with active substances classified according to the Biopharmaceutic Classification System. , 2010, British journal of clinical pharmacology.

[2]  R. P. Hunter,et al.  Current challenges facing the determination of product bioequivalence in veterinary medicine. , 2010, Journal of veterinary pharmacology and therapeutics.

[3]  P. Lees,et al.  Influence of feeding schedule on the absorption of orally administered flunixin in the horse. , 2010, Equine veterinary journal. Supplement.

[4]  Leslie Z Benet,et al.  Predicting drug disposition via application of a Biopharmaceutics Drug Disposition Classification System. , 2010, Basic & clinical pharmacology & toxicology.

[5]  Terry Hyslop,et al.  Evaluation of a Scaling Approach for the Bioequivalence of Highly Variable Drugs , 2008, The AAPS Journal.

[6]  Jack A. Cook,et al.  Summary Workshop Report: Bioequivalence, Biopharmaceutics Classification System, and Beyond , 2008, The AAPS Journal.

[7]  Lawrence X. Yu,et al.  Highly Variable Drugs: Observations from Bioequivalence Data Submitted to the FDA for New Generic Drug Applications , 2008, The AAPS Journal.

[8]  Vinod P. Shah,et al.  The Use of BDDCS in Classifying the Permeability of Marketed Drugs , 2008, Pharmaceutical Research.

[9]  A. Urtti,et al.  Pharmacokinetic simulation of biowaiver criteria: the effects of gastric emptying, dissolution, absorption and elimination rates. , 2007, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[10]  P. Toutain,et al.  Bioavailability and its assessment. , 2004, Journal of veterinary pharmacology and therapeutics.

[11]  Thomas J. Vidmar,et al.  Predicting Drug Absorption: How Nature Made It a Difficult Problem , 2002, Journal of Pharmacology and Experimental Therapeutics.

[12]  L. Augsburger,et al.  Applying the biopharmaceutics classification system to veterinary pharmaceutical products. Part I: biopharmaceutics and formulation considerations. , 2002, Advanced drug delivery reviews.

[13]  G. Amidon,et al.  Applying the biopharmaceutics classification system to veterinary pharmaceutical products. Part II. Physiological considerations. , 2002, Advanced drug delivery reviews.

[14]  Vinod P. Shah,et al.  Biopharmaceutics Classification System: The Scientific Basis for Biowaiver Extensions , 2002, Pharmaceutical Research.

[15]  D. Conner,et al.  Challenges associated with the evaluation of veterinary product bioequivalence: an AAVPT perspective. , 2002, Journal of veterinary pharmacology and therapeutics.

[16]  E. Brendel,et al.  Dosage form-related food interaction observed in a marketed once-daily nifedipine formulation after a high-fat American breakfast , 2002, European Journal of Clinical Pharmacology.

[17]  J. Wilton,et al.  Lack of Bioequivalence of Ciprofloxacin When Administered with Calcium‐Fortified Orange Juice: A New Twist on an Old Interaction , 2002, Journal of clinical pharmacology.

[18]  E. Brendel,et al.  Formulation-dependent food effects demonstrated for nifedipine modified-release preparations marketed in the European Union. , 2002, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[19]  B. Schug,et al.  The biopharmaceutics classification system (BCS): class III drugs - better candidates for BA/BE waiver? , 1999, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[20]  A. Vulto,et al.  In vitro and in vivo binding of trimethoprim and sulphachlorpyridazine to equine food and digesta and their stability in caecal contents. , 1996, Journal of veterinary pharmacology and therapeutics.

[21]  D. Hennessy,et al.  The effect of level of feed intake on the pharmacokinetic disposition and efficacy of ivermectin in sheep. , 1996, Journal of veterinary pharmacology and therapeutics.

[22]  J. Crison,et al.  A Theoretical Basis for a Biopharmaceutic Drug Classification: The Correlation of in Vitro Drug Product Dissolution and in Vivo Bioavailability , 1995, Pharmaceutical Research.

[23]  L. Tonkinson,et al.  Effect of bentonite incorporated in a feed ration with tilmicosin in the prevention of induced Mycoplasma gallisepticum airsacculitis in broiler chickens. , 1994, Avian diseases.

[24]  P. Lees,et al.  Absorption and pharmacokinetics of phenylbutazone in Welsh Mountain ponies. , 1986, Journal of veterinary pharmacology and therapeutics.

[25]  Terry Hyslop,et al.  Evaluation of a Scaling Approach for the Bioequivalence of Highly Variable Drugs , 2008, The AAPS Journal.

[26]  Lawrence X. Yu,et al.  Bioequivalence Approaches for Highly Variable Drugs and Drug Products , 2007, Pharmaceutical Research.

[27]  P. Lees,et al.  In vitro and in vivo binding of phenylbutazone and related drugs to equine feeds and digesta. , 1988, Research in veterinary science.