Dry granulation-干法制粒

ROLLER COMPACTION
• Dry roller compaction is the process of using mechanical pressure to compress fine powders into denser sheets. The basic concept of compaction is to force fine powders between two counter rotating rolls. As the volume decreases through the region of maximum pressure, the material is compressed into dense sticks or corrugated sheets. These sheets are then granulated through a milling system and series of screens to achieve the precise, uniform granule size specified. Dry roller compaction is the best granulation process for materials sensitive to moisture and heat. Unlike wet granulation processes, which require liquid binders, alcohol solvents and high temperature drying, roller compaction is free of these additional ingredients and energy requirements. The end result is a higher quality, consistent granule—usually at a lower cost.
PRESENTATION ON DRY GRANULATION
PRESENTED BY GIRGIS ATTIA
INTRODUCTION
• Tablets as a dosage form are composed of active pharmaceutical ingredient (API/s) and non active pharmaceutical ingredients. • These altogether are known as raw materials and are supplied in powdered form
• 1) WET GRANULATION: • MIXING WET MASSING screening of granules drying lubrication compression • 2) Dry granulation: no water or granulating fluid • A) SLUGGING: original employed method B) ROLLER COMPACTION
CONT.
• 4) Logistics: Wet granulation processes tend to be expensive, labour intensive and time consuming. It also require highly skilled operators and a high degree of processing control. • 5)Dry granulation tend to produce adjustable and easy to manipulate grain size, bulk density, flowability and solubility of processed granules • 6)Dry granulation process enhance solid dosage forms stability by increasing final tablet hardness and reducing tablet friability • 7)Wet granulation tends to produce smooth spherical granules that possess good to excellent flowability characteristics • 8) Dry granulation can be a continuous fully automated process with high throughput. Validation being required for the process as whole, whereas in wet granulation validation is required for each and every step.
2) To prevent segregation of the ingredients in the mix 3) To improve compressability
4) To decrease environmental hazards for personnel from dust formation
A) Initial granulation was forced down hoppers of big tablet processes that were fitted with large flat punches, about 1 inch in diameter.
B) These large slugs were subsequently broken down using oscillators or mills to form granules
FACTORS INVOLVED IN SELECTION OF GRANULATION METHOD
• Typically selection of an appropriate granulation method is based on material properties of the proposed formulation, end requirements of the granules and obviously the tablet or capsule • 1) stability under processing conditions: many active components are heat and or moisture sensitive, and under these circumstances Dry Granulation would be preferable. • 2)moisture content: absence or low presence of moisture in dry processed materials allow the product to maintain a high level of drug stability over longer periods of time as chemical and/or microbial degradation are minimized. • 3)Wet granules often lead to prolonged disintegration times, and thus the dry granulation process may be more suitable for simple immediate release tablet applications.
WHY GRANULATION
1) To improve the flow properties of a bulk powder mix: Because of their small size and or surface characteristics, many powders are cohesive (sticky) and do not flow well.
• •Sized specifically to meet your precise product requirements. Roller compaction offers control and range of granule size.
5) To reduce material adherence when some powder components are hygroscopic 6) To decrease bulk volume and increase bulk density of powders
TYPES OF GRANULATION METHODS
ADVANTAGES OF DRY GRANULATION
• In addition to high quality and consistency, dry roller compaction produces granules that are: •More durable, for improved crush strength. • •Uniform, for more even downstream blending. Roll compaction produces consistent, irregular-shaped granules that "interlock" to reduce product stratification during shipping and handling. • •Highly flowable powders compared to powders that bridge and cake. Tableting and other downstream processes are more efficient.