HPMC CAPSULES IN DPIs. EVALUATION OF THE PUNCTURING FORCE USING CAPSULES MADE WITH DIFFERENT MANUFACTURING METHODS AND COMPOSITIONS
Deepak Patil1, Jnanadeva Bhat1, Sanjay Powale1, Ajay Giripunje1, Justin Kalafat2, Fernando Diez3
1ACG SciTech Center, 7 Prabhat Nagar Patel Estate, Jogeshwari (West), Mumbai, 400102, India
2ACG North America, LLC, 262 Old New Brunswick Rd, Piscataway, NJ, USA
3 ACG Europe, 159 Princes Gardens, W3 0LS, London, United Kingdom
Capsules based inhalers belong to the category of dry powder inhalers. Their importance arises as a drug delivery component when high drug doses must be delivered directly to the lungs. The process consists of two steps; capsule puncturing and aersolization. The use of this platform is not only restricted to pulmonary diseases, as new products for Parkinson disease and acute migraines are being developed using these types of inhalers.
Most of these new products use HPMC capsules with a gelling agent in the formulation. These capsules perform well in the puncturing process, and most of the studies reviewed in the reference section refer to these capsules. 
In this study we focus on another type of HPMC capsules, with two noticeable differences from the legacy product. First is the composition, as the standard capsules use a gelling agent (normally carrageenan) and a gelling promoter. The second generation of HPMC capsules only consist of the polymer, hypromellose, and water. The other difference refers to the manufacturing process (hot versus cold) in which the temperature of the pin bars are drastically changed. The standard capsules are made with pin bars at a temperature of 20-25 ºC, and the absence of the gelling promoter makes it necessary to elevate the temperature to 65-70 ºC for the capsules to form on the pins.
Puncturing forces are measured for both types of HPMC capsules, detailing the correlation between capsule thickness and puncturing force . There are not significative differences between both capsules.
This capsule is an additional tool for the formulator to design innovative systems in product development of generic and new products.