Add referrence to Micosoft.SQLServer.ManagedDTS.dll. It is in your SQL Server Program Files Folder\SDK\Assemblies.

using Microsoft.SqlServer.Dts.Runtime;

namespace ExecuteSSIS
{
class Program
{
static void Main(string[] args)
{
Application app = new Application();
//
// Load package from file system
//
Package package = app.LoadPackage(@”c:\myPackage.dtsx”, null);
package.ImportConfigurationFile(@”c:\myPackage.dtsConfig”);
//Pass parameters
Variables vars = package.Variables;
vars[“variable”].Value = “values”;
DTSExecResult result = package.Execute();
Console.WriteLine(“Package Execution results: {0}”,result.ToString());

//
// Load package from Sql Server
//
Package package2 = app.LoadFromSqlServer(
“myPackage”,”server_name”, “sa”, “password”, null);
package2.ImportConfigurationFile(@”c:\myPackage.dtsConfig”);
//Pass parameters
Variables vars2 = package2.Variables;
vars2[“variable”].Value = “value”;
DTSExecResult result2 = package2.Execute();
Console.WriteLine(“Package Execution results: {0}”,
result2.ToString());
}
}
}