Dry powder Inhalers (DPIs) - Lab Report Example

Dry powder Inhalers (DPIs) Introduction: The treatment of the pulmonary disorders is done by delivering the drug directly to the lungs by using drypowder inhalers (DPI). DPI is the recent and most efficient technique to deliver the drug to the lower respiratory tract. The DPIs are able to deliver 10 to 20 % of the drug used. The efficiency of delivery can be improved if we increase the powder formulation, inhaler device design or the inhaler effort of the patient. As the last two things are not practically possible, the powder formulation was chosen for the experiment.

In this experiment, the effect of the powder formulation with lactose as the carrier molecule and the effect of the inhalation flow rate are studied. Aim: To determine the effect of flow rate on the drug absorbance and to check whether Theophylline lactose drug – carrier interaction is best suited for the pulmonary drug delivery. Results: For the drug and carrier, the recovered rate is 1.76565 mg. Emitted dose level is 0.8267 mg and the amount deposited in the upper stage is 0.4164 mg and that in the lower stage is 0.4103 mg. the amount deposited in the lower stage is the fine particle dose.

The dispersibility level of the drug and carrier is 46.82%. The fine particle fraction (FPF) is 49.63%. For 30ml/min flow rate, the recovered dose is 1.224 mg . The Emitted dose level is 0.444 mg and the amount deposited in the upper stage is 0.3 mg and that in the lower stage is 0.144 mg. The dispersibility level is 36.28%. The fine particle fraction (FPF) is 32.43 %. For 60 ml/ min flow rate, the recovered dose is 2.167 mg. The Emitted dose level is 1.127mg and the amount deposited in the upper stage is 0.

634 mg and that in the lower stage is 0.493 mg. The dispersibility level is 51.99%. The fine particle fraction (FPF) is 43.75%. Discussion: The drug molecules are carried to the required region with the help of the carrier molecule. Here the drug is Theophylline and the carrier molecule is lactose. Theophylline is the drug that is used widely for the treatment of asthma and other respiratory diseases. Lactose is the major carrier molecule of many drugs. The main reason for using this is the multiple characters of lactose.

It acts as a good diluents, carrier molecule, preservative and also helps in the absorption of the drug. It is also found to enhance the bioavailability of the drug. The cost effectiveness, the ease of availability , blend taste, low hygroscopicity, water solubility, good strength, physical and chemical stability are some of the reasons for using lactose as the carrier molecule. For the wet and dry compression tablets, lactose is most commonly used. When the drug is delivered to the site at different flow rates, the rate of drug emitted and recovered varied.

The dispersibility level of the drug at 30 ml/ min flow rate was drug is delivered to the site at different flow rates, the rate of drug emitted and recovered varied. The dispersibility level of the drug at 30 ml/ min flow rate was 36.28% and that of the 60ml/min flow rate was 51.99%. There is a significant change in the dispersibility rate of the drug. Similarly the amount of drug that reaches the lower stage also varied. The FPF values were 32.43 and 49.75% respectively. If the dispersibility rate is higher then the amount of drug reaching the lower stage is very less.

This indicates that only very less amount of drug reaches the organs. The remaining drug gets dispersed in the pathway itself. Because of the increase in the flow rate, the retention time of the molecule becomes very less and the molecules are not completely absorbed by the organ. Slower the inhalation rate, greater the absorption of the molecule. Another important thing to note is the fine particle fraction. The rate is higher for the 60 ml/ min flow rate. During the wet granulation, lactose absorbs the water molecule and becomes very compact in size.

The hygroscopic nature of lactose is the main reason. The soluble excipient lactose is present in the top layer as preservative and filler. If the core size of the tablet is one of the important factor for the drug release. If the core diameter is small, then the lag time of the tablet will be less and the release of the drug will increase. Because of this reason only the Theophylline and lactose are chosen together. (Efentakis, Iliopoyloy and Siamidi 2011). 63-90µm of lactose powder was used in the experiment.

This particle size of the lactose was found to have lower bulk density and tap density. The flow rate was very less. This lactose was found to have decreased diameter than the drug at the inhaler device, thus reducing the amount of drug deposited at the inhaler device. The rougher surface and the higher fine particle content of the lactose was found to increase the drug aerosolisation process. ( Kaialy et al. 2011). References: Efentakis ., M., Iliopoyloy ., A., and Siamidi ., A, 2011, Effect of core size and excipients on the lag time and drug release from a pulsatile drug delivery system, Drug development and industrial pharmacy, vol.

37, No 1, pp 113-120. Kaialy ., W., Martin., GP., Larhrib., H., Ticehurst., MD., Kolosionek., E., and  Nokhodchi., A., 2011, The influence of physical properties and morphology of crystallised lactose on delivery of salbutamol sulphate from dry powder inhalers, Colloids and surfaces, Biointerfaces, vol. 89, pp 29-39.