GC Smart 500, Glatt’s intelligent pan coating system
PHARMA FOCUS: OSD FORMS
How to solve your
tablet coating problems For tablet-based medicines, pharma plants in Africa need the capacity to produce roughly half a billion tablets annually to be competitive to India. P C Africa shares advice from Glatt on how to overcome 10 key challenges in the tablet coating process.
P
harmaceutical markets in subSaharan Africa are growing at a rapid pace as governments and healthcare providers battle
PROBLEM
DESCRIPTION
POSSIBLE EXPLANATIONS
SOLUTIONS
Tablet surface is rough or uneven
• distance between nozzle and tablet bed is incorrect • spray angle is wrong • dispersion sedimentation • viscosity or solid content is too high • high friability from inadequate core properties • incorrect atomising air pressure (too high or low)
• increase the spray rate • decrease drying capacity • reduce atomising air pressure • decrease viscosity • optimise distance between the nozzle and tablet bed
Filling in of the logo or break line
• viscosity is too high • plasticiser content is too low • spray rate is too high • atomising air pressure is incorrect
• decrease viscosity • increase plasticiser content • reduce the spray rate • adjust the spray pressure
Two or more tablets stick together
• over-humidification • process air volume is too low • unsuitable tablet shape planar
• reduce spray rate • increase the drying capacity • optimise tablet form to biconvex • use releasing agents in the formulation
Coatings are ripped off when tablets stick
• pan speed is too low • air temperature is too low • process air volume is too low • spray rate is too high • process is too damp
• increase the pan speed • increase the inlet air temperature • increase the process air volume • reduce the spray rate
Grey layer forms on the tablet surface
• TiO2 quantity is too high • interaction occurs between the drum wall and the coating
• reduce TiO2 quantity • spray the drum prior to the trial
Film surface detaches from the tablet
• hygroscopic core • disintegrants are used
• use a subcoat • optimise process parameters
Batch colour is varied
• coverage properties of the coating are insufficient • solid content of the suspension is too high • weight gain level is too low • batch quantity is too low
• add more pigment to increase coverage property • reduce the solid content • increase weight gain level
• application rate is too low • API interacts with the coating material • low opacity • API diffuses from the core • overhumidification
• increase weight gain • adapt the formulation or change the pigments • increase coverage properties of the coating formulation • use a subcoat • increase tablet bed temperature
Orange peel/ roughness
the burdens of disease. Although the continent is home to only 15 percent of the world’s population, disease is one of its biggest challenges. The drive to control and ultimately, eradicate communicable diseases
Logo bridging
such as HIV/Aids and tuberculosis presents pharma manufacturers with immense opportunities for growth in the Africa market. In sub-Saharan Africa,
Twinning
countries such as Kenya, Nigeria and South Africa have a relatively sizable pharmaceutical industry, according to McKinsey & Company. Dozens of the pharma companies in these countries
Sticking and ripping off coating
produce everything from simple, small molecules, such as generics in tablet, capsule and syrup formats to the more complex combination drugs, injectables
Scuffing
and vaccines. These pharma products are produced for regional consumption
Capping
and, in some cases, to export to neighbouring countries. Pharma industry information released
Batch colour variation
in January by McKinsey & Company
Individual colour variation Uneven colour on individual tablets
Peeling Film spalling due to coating cracking
• tablet swells • plasticiser content is too low • tablet is too wet • tablet hardness in insufficient • tablet outgasses
Friability
Tablet mass reduced due to abrasion
An interior view showing the innovative spray technology within the GC Smart 500
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| QUARTER 1 2019 | P C Africa
• mechanical stress • tablets are too soft • tablets are too damp • pan speed is too high
• use a subcoat • increase plasticiser content • spray with drier conditions • increase the film forming polymer • reduce the pan speed • optimise the core formulation • spraying with drier conditions • use the interval ‘jog mode’ while heating cores