Some real quick code to extract NDC values and specific attributes from a FDA SPL XML document. Provided as-is.

ruby_code.rb

# Input: FDA SPL XML file (can be found at http://dailymed.nlm.nih.gov/dailymed/)
# Output: Array of hashes containing NDCs and their sizes

# This code is provided AS-IS: THE INFORMATION CONTAINED HEREIN OR ANY SITE-RELATED SERVICE, IS PROVIDED "AS IS" WITH NO REPRESENTATIONS OR WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NONINFRINGEMENT.  YOU ASSUME TOTAL RESPONSIBILITY AND RISK FOR YOUR USE OF THIS SITE, SITE-RELATED SERVICES, AND ANY HYPERLINKED WEBSITES.

require 'pp'
require 'rexml/document'

xml_file = "12e3a517-4858-42f3-ab2e-062f1a592737.xml" # or use ARGV[0] to take in a command-line argument
xml_doc = REXML::Document.new(File.read(xml_file))

data_to_return = []

# find specific characteristics
size_elements = xml_doc.elements.to_a("//code[@code='SPLSIZE']")
size_elements.each do |size_element|
  ndc_data = {}
  characteristic = size_element.parent
  manufactured_product_parent = characteristic.parent.parent

  # look up/backwards for NDC information  
  manufactured_products = manufactured_product_parent.elements.to_a("manufacturedProduct")
  manufactured_products.each do |manufactured_product|
    manufactured_product.elements.to_a("code[@codeSystem='2.16.840.1.113883.6.69']").each do |ndc|
      ndc_data[:ndc] = ndc.attributes["code"]
    end
  end

  # store information for this ndc
  size_values = characteristic.elements.to_a("value")
  size_values.each do |size_value|
    ndc_data[:unit] = size_value.attributes["unit"]
    ndc_data[:size_value] = size_value.attributes["value"]
  end

  data_to_return << ndc_data
end


puts data_to_return.inspect
# [
#   {:unit=>"mm", :ndc=>"61748-015", :size_value=>"18"},
#   {:unit=>"mm", :ndc=>"61748-018", :size_value=>"20"}
# ]

Revision #1 -> #2 changes: fixing indentation formatting