Pellets are prepared by utilisation of freeze drying method in this technique. Vision Pharmaceuticals employs industry leading Lyophilisation techniques and produces highest quality sustained release, taste masked pellets that otherwise impossible to manufacture due to water sensitivity. Liquid nitrogen (-196 °C) is used as a medium, that causes freezing of droplets of liquid formulations into solid spherical particles which, then Lyophilised to produce pellets.
In this technique material freezes Immediately and uniformly due to rapid heat transfer from material’s droplets to liquid nitrogen. The total amount of liquid nitrogen required dependent upon quantity of solution. The equipment consists of a nitrogen container and a conveyor which with its variable speed maintains the required residence time for freezing the Pellets. Frozen pellets stored in a storage container (Temperature -60°C ) before drying. In this process droplet formation a critical step influenced by many variables like nature, viscosity, surface tension, solid content of the solution and equipment design.
Hot Melt Extrusion:
HME a robust and novel technique used in Pharmaceutical industry to produce various drug delivery system. This technique utilised by very few Pharmaceutical industries throughout South Asia, Vision Pharmaceutical proud of its engineering unit to utilise such a novel and advanced manufacturing system.
This method involves compaction and blend of powder into uniform shaped pellets. Melted polymers, binders, excipients and active drugs forced through a die under control temperature, pressures, screw speed etc to form uniform shaped pellets.
Whole process carried out in following major steps.
Feeding of extruder through hopper.
Mixing, grinding, kneading.
Flow through the die under controlled conditions.
Extrusion and further processing.
Vision Pharmaceutical uses this technique for the variety of benefits including but not limited to.,
. Pellitization of drugs with poor bioavailability.
. For preparation of taste masked dosage forms.
. To make a stable dosage form,in case the drug water sensitive.
. Formulation preparation for control release dosage forms.
. For uniform suspension of drug particles with better content uniformity.
In this technique, a molten solid carrier into which the drug uniformly dispersed entered as tiny droplets into, inert liquid in which molten solid carrier completely immiscible. This tiny droplets get solidified Into spherical pellets. These tiny droplets can move in either direction depending upon the density of the solid carrier. If the density lower compared to inert liquid than molten solid is introduced from the bottom and droplets will flow from bottom to upward coulmn. But if the density higher than inert liquid then molten solid introduced from the upward coulmn. Melting point of solid carrier used for this process below 100°C so that it can remain solid at room temperature. In order to obtain uniform shaped spherical pellets. Viscosity of the drug medium should be optimum, ideally between 4 and 40 cP at 20 °C.