• Delivery tube: Made of rigid, hollow stainless steel 18-gauge tubing with rounded tip and 120-degree bend.
• Length of intratracheal portion for Rat: 2″ (5 cm) after 120-degree bend
• Outer diameter: .050″ (1.1 mm) except at rounded tip which is .058″
• Inner diameter: .038″ (Hollow throughout)
• Reusable/Sterilizable: Stainless steel delivery tube and PEKK™ plastic hub are detachable, and can be cleaned with liquid methods, and autoclavable. NOTE: Dry methods of cleaning are preferred for main PEEK™ portions of device

Penn-Century Dry Powder Insufflator™ – Model DP-4 consists of an Air Intake and Sample Chamber to which a hollow delivery tube is connected. The device twists open at the center to permit the Sample Chamber to be filled manually with a small single dose (1 – 5 mg) of powdered material, using a narrow spatula. The two halves are then gently but firmly press-fit back together, protecting the powder sample from ambient air and moisture. The tip of the air source, either the 3 ml air syringe or the Penn-Century Air Pump, is then inserted into the opening at the back of the Air Handler. The delivery tube is made of stainless steel and is attached to the device by a PEEK™ fitting. The tube and fitting can be unscrewed from the Sample Chamber and cleaned separately using wet methods if desired. It must be thoroughly dried before reattaching to the device. NOTE: Powder should neverbe loaded into the Air Handler as this may prevent the device from functioning properly.

Delivery tube of Dry Powder Insufflator™ – Model DP-4-R for Rat

For intratracheal applications with the Dry Powder Insufflator™ optimal concentration and uniform deposition in the lung is achieved when the tip of the device is close to but not touching the carina. The intratracheal portion of the Model DP-4-GP is designed to be inserted into the trachea and reach from the front incisors to the carina in a standard size guinea pig.

Users may also pre-intubate the animal and insert the device down the trachea to the carina via an endotracheal tube. Doing so requires that the user calculate the measurements carefully:

1. If tip of the Dry Powder Insufflator™ is inserted into an endotracheal tube, the distal tip must emerge slightly from the end of the endotracheal tube when it is in position
2. To avoid injury, neither the distal tip of endotracheal tube nor the distal tip of the Dry Powder Insufflator™ should make contact with the carina when the plunger of the air syringe is pushed

The process of intratracheal administration is essentially a form of intubation. For intrapulmonary applications, the tip of the device is gently inserted down the trachea of the anesthetized animal – near to, but not touching the carina (first bifurcation).

For complete details, please refer to the Instructions for Use for the Penn-Century Dry Powder Insufflator™ – Model DP-4

Overview

• A precision balance is required to quantify the dose.
  Use of the Dry Powder Insufflator™ – Model DP-4 requires a precision scale or balance. The device must be precisely weighed before and after filling and after each application of air to quantify the delivered dose and to determine how many applications of air will be required to dispense 100% of that dose.
• Insufflation of the powder sample. The Model DP-4 is operated with either a 3 ml commercial air syringe (provided) or a Penn-Century Air Pump (sold separately.) The air source is firmly press-fit into the proximal end of the Air Handler to insufflate the powder sample with puffs or pulses of air. NOTE: To avoid injury and hyperinflation to the experimental animal, the volume of air in the air source must be set to the correct volume for the lung capacity of the experimental animal. For rat, air volumes must not exceed 2 ml. For guinea pig, air volumes must not exceed 3 ml. Some powder formulations may require more than one application of air to dispense 100% of the powder.
• Positioning of the delivery tube in the trachea. For optimal deposition and distribution in the lung, the very tip of the Dry Powder Insufflator™ must be carefully positioned in the trachea of the anesthetized animal so that the tip of the delivery tube is above, but not touching the carina, as indicated in the drawing (right). To insufflate the powder with an air syringe requires the user to push the plunger rapidly and with force. At the same time, great care must be taken, when pushing the plunger of the air syringe, to avoid excessive hand motion that may result in pushing the tip of the device forward and causing injury to the animal. If the user is using a spring-loaded Penn-Century Air Pump instead of the air syringe, less force and hand motion is required to produce a puff of air of a specific volume. For detailed technical information, refer to the Instructions for Use.
• Cleaning of the main device body – Dry methods preferred
  In general, the Dry Powder Insufflator™ is constructed of sterilizable materials. Due to the complex nature of the valve system inside, dry methods of cleaning are preferred. Liquid methods of cleaning the device, such as alcohol, organic solvents (ethanol or methanol), or water are less desirable than physical methods. Liquids, especially water, may work themselves into small crevices where they may interfere with subsequent powder deliveries. (Please note that dessication systems are designed to remove water – not solvents.) To clean the Sample Chamber, detach it from the Air Intake and direct a small stream of air or other compressed gas (“Dust-Off” or a similar product for cleaning computer keyboards will do). Take care not to thrust the nozzle of the air source into the Sample Chamber to avoid damage to the valve assembly. Do not use excessively forceful compressed air sources. If you have particular questions or concerns about acceptable methods of cleaning, feel free to contact us with your questions.
• Cleaning the stainless steel delivery tube
  The delivery tube of the device is hollow and detachable, and may be cleaned separately. The device may be autoclaved or immersed in water, organic solvent or disinfectant. It should be thoroughly and completely dried – using compressed air or by air drying it – prior to reattaching to the body of the device. To remove the delivery tube, simply twist the 10-32 fitting 1/4-turn counterclockwise and pull the tube out. To replace, push the stainless steel tube in to a hard stop and twist the fitting 1/4-turn clockwise, or until some resistance is felt. Do not overtighten.