title: Microbiological equivalence of bacteriostatic and bactericidal activities of the sera from healthy volunteers receiving generic piperacillin/tazobactam (Pipertaz) and original piperacillin/tazobactam (Tazocin).
abstract: BACKGROUND
  Several generic piperacillin/ tazobactam formulations have been approved by Thai Food andDrugAdministration, Ministry of Public Health. Piperacillin/ tazobactam is a parenteral drug. Therefore, a study demonstrating a biological equivalence of generic piperacillin/ tazobactam is not required for drug registration in Thailand.
  
  
  OBJECTIVE
  The study was to determine microbiological equivalence of serum bacteriostatic and bactericidal activities of the sera from healthy volunteers receiving generic piperacillin/ tazobactam (PipertazA) and original piperacillin/tazobactam (Tazocin).
  
  
  METHODS
  This was a randomized crossover study in 16 adult healthy volunteers. Each subject received 4.5 grams of Pipertaz and Tazocin in 50 ml of normal saline via intravenous infusion for 30 minutes. The blood samples were drawn at baseline prior to receiving the study drug, at 30 minutes after initiating infusion, and at 8 hours after initiating infusion. The serum bacteriostatic activity against E. coli ATCC 25922, K. pneumoniae, P aeruginosa ATCC 27853 and A. baumannii was performed by disk diffusion The serum bactericidal activity against E. coli ATCC 25922 was performed by Serum Bactericidal Titre.
  
  
  RESULTS
  The average inhibition zone diameter of the serum samples from the subjects while receiving Pipertaz against each tested organisms was <1 mm smaller than that while receiving Tazocin and such difference was not significantly different. All serum samples collected at 30 minutes after initiating Tazocin and Pipertaz had bactericidal titres 1:64 to 1:256 against E. coli ATCC 25922. All serum samples collected at 8 hours after initiating Tazocin and Pipertaz had bactericidal titres < 1:2 against E. coli ATCC 25922. The differences of serum bactericidal titres of the serum samples collected at 30 minutes (p = 0.7) and 8 hours (p = 1.0) after initiating Tazocin and Pipertaz were not statistically significant.
  
  
  CONCLUSIONS
  The sera from healthy volunteers receiving Pipertaz contain bacteriostatic and bactericidal activities not significantly different from those receiving Tazocin.
authors: Department ofMedicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. sivth@mahidol.ac.th
authors: Visanu
authors: V
authors: Thamlikitkul
authors: Surapee
authors: S
authors: Tiengrim
authors: Chalobol
authors: C
authors: Chalermsri
authors: Ratikorn
authors: R
authors: Sae-Jong
authors: Siriluk
authors: S
authors: Suddhichupaiboon
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D018592:Cross-Over Studies; D004359:Drug Therapy, Combination; D016568:Drugs, Generic / Q000494:pharmacology*; D005260:Female; D006801:Humans; D020128:Inhibitory Concentration 50; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology; D010878:Piperacillin / Q000097:blood / Q000494:pharmacology; D000077725:Piperacillin, Tazobactam Drug Combination; D015610:Serum Bactericidal Test; D013785:Thailand; D013810:Therapeutic Equivalency; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D016568:Drugs, Generic; D000077725:Piperacillin, Tazobactam Drug Combination; D010397:Penicillanic Acid; D010878:Piperacillin