Simulations Plus


Leading the physiologically based pharmacokinetic (PBPK) modeling & simulation revolution...

And again come out ranked #1 in terms of accuracy vs. other commercial PBPK programs.

See how scientists at Roche and Janssen are applying GastroPlus PBPK modeling to eliminate bridging clinical studies for late stage and post-approval changes!

What is GastroPlus™?

GastroPlus is a physiologically based pharmacokinetic (PBPK) modeling & simulation software package that simulates intravenous, oral, oral cavity, ocular, inhalation, and dermal/subcutaneous absorption, pharmacokinetics, and pharmacodynamics in human and animals. Since 1997, Simulations Plus has evolved the ACAT™ (Advanced Compartmental Absorption and Transit) model to a high state of refinement, providing the industry's most accurate, flexible, and powerful simulation software. This smoothly integrated platform combines a user-friendly interface with sophisticated science to help you make better project decisions... faster!

Check out what's new in GastroPlus 9.0! This major release strengthens the "marriage" between PBPK & QSAR modeling, while expanding GastroPlus simulations into dermal, subcutaneous, and oral cavity administration. Plus, the software now has PBPK models for the "Goliaths" - biologics!

GastroPlus is, by far, the most commonly used software of its kind. This includes all of the top 20 pharmaceutical companies, along with companies based in India, China, Korea, Japan, Brazil and more! It has been identified as the #1-ranked tool for in vitro-in vivo extrapolation (IVIVE) and PBPK modeling, and has been the focus of several recent publications from the FDA!

See how our clients are using GastroPlus by reviewing the peer-reviewed publication list!

How is it being applied?

  • Predict first-in-human/animal doses through QSAR/PBPK modeling
  • Rapid analysis and understanding of the behavior of drug candidates in animals and human
  • Assess effects of influx and efflux transporters in gut or any tissue
  • Conduct virtual population PK/PBPK studies & bioequivalence trials - with expanded statistical reporting!
  • Fit complex nonlinear metabolism and transport in any tissue
  • Build PBPK/PD models with target tissue concentrations
  • Track multiple metabolites (and metabolites of metabolites)
  • Assist with Quality by Design (QbD) implementation
  • Deconvolute in vivo dissolution for IVIVC to guide formulation development and dissolution method design activities
  • Predict steady-state and dynamic drug-drug interactions (DDI) - includes metabolic- and transporter-based interactions & induction 
  • Identify appropriate dose levels and dosing regimens in pediatric populations
  • Understand food effects
  • Support animal or human risk assessment studies
  • ... and more!

What is accounted for in the GastroPlus simulations?

For Dissolution & Absorption:

  • The Advanced Compartmental Absorption and Transit (ACAT) model - only in GastroPlus!
  • Physiological gut models for human, beagle dog, rat, mouse, cynomolgus monkey, rhesus monkey, minipig, rabbit, and cat - fasted or fed conditions defined
  • Vast selection of IV and oral dosage forms: intravenous (bolus or infusion), immediate release (tablet, capsule, suspension, solution), and controlled release (gastric retention, dispersed release, integral tablets)
  • pH-dependent solubility and logD models - ionization effects on dissolution & absorption considered
  • Paracellular absorption - estimate paracellular permeability and predict both passive diffusion and paracellular absorption pathways
  • Peff converter to convert user-measured permeability to human in vivo Peff
  • Mechanistic effect of bile salts on in vivo drug solubility and dissolution
  • Mechanistic model for in vivo precipitation - based on nucleation kinetics
  • Enhanced treatment of nanoparticle effects on solubility and dissolution
  • pH-dependent chemical degradation in the lumen
  • Options for defining pH-dependent dissolution (Z-factor models) and precipitation rates
  • Dissolution and precipitation dependence on particle size, shape and particle density
  • Saturable metabolism and/or influx/efflux transport along the GI tract (with optional Metabolism and Transporter Module)
  • Mechanistic In Vitro - In Vivo Correlation (IVIVC) for various formulations (with optional IVIVCPlus™ Module)
See how scientists at Merck are applying mechanistic absorption modeling with GastroPlus to address challenges in formulation development.

For Pharmacokinetics:
  • Whole body, physiologically-based pharmacokinetic (PBPK) models defined (with optional PBPKPlus™ Module)
  • Infant & pediatric PBPK modeling - simulate for infants as young as 16 weeks premature, with automatic scaling of physiological parameters (with optional PBPKPlus™ Module)
  • One-, two-, or three-compartment conventional pharmacokinetic model options available
  • Transporter-based IVIVE: automated scaling of permeability across all tissues with PBPK models (with optional PBPKPlus™ Module)
  • Saturable metabolism and transporter in liver or any PBPK tissues (with optional Metabolism and Transporter Module)
  • Metabolite tracking - easily link the formation of metabolites with the metabolism of parent(s) in a single simulation (with optional Metabolism and Transporter Module)
  • Mechanistic treatment of biliary secretion, enterohepatic circulation, and urine excretion
  • Drug-Drug Interactions (with optional DDI Module) - both metabolic- and transporter-based interactions
  • Models for predicting drug administration through ocular, pulmonary, dermal/subcutaneous, or oral cavity routes (with optional Additional Dosage Routes Module )
  • Automated pharmacodynamic model selection (PK/PD or PBPK/PD) with industry standard models (with optional PDPlus™ Module)
Simulation Modes Available:
  • Population Simulator™ - predict likely distributions of PBPK/PD and DDI results over different populations
  • Parameter Sensitivity Analysis - quickly test sensitivity of results to changes in any model parameters
  • Batch Simulations - screen compound libraries for bioavailability & PK exposure in different species
  • Automated model fitting for single or multiple data sets (with optional Optimization Module)

GastroPlus Saves Time

As pharmaceutical, biotechnology, food ingredient, industrial chemical, and cosmetic companies strive to reduce the enormous costs and time required to bring new products to market, computer tools have become an important and necessary part of drug discovery and development. From simple spreadsheets to sophisticated supercomputer molecular dynamics models, the ability of researchers to experiment in silico has become an important complement to in vitro and in vivo experimentation. GastroPlus expands state-of-the-art PBPK modeling & simulation and allows the "masses" to enjoy the benefits.