Maintenance of automatic tablet press is done by adhering to strict daily cleaning routines with 3% hydrogen peroxide solution as in-place cleaning (CIP) with a flow rate of 50L/min and pressure of 3bar. It takes 45 minutes and can reduce the risk of microbial contamination by 89%. According to the record of a drug company, in 200 hours of equipment running without cleaning, the surface of the residue of the mold is 0.15mg/cm² (super GMP standard 0.1mg/cm²), which causes tablet dissolution deviation ≥5%. It is recommended that the whole machine needs to be sterilized 8 hours after production time, and apply the ultraviolet sterilization system (wavelength 253.7nm, intensity 80μW/cm²) for 30 minutes to control the number of environmental colonies to within 10CFU/m³.
The lubrication system maintenance directly influences the equipment life. The main bearing of automatic tablet press has to be injected with food-grade lithium base grease every 500 hours (NLGI grade 2, dose 2-5g/point) and the gearbox substituted with ISO VG 68 lubricating oil every 2000 hours (volume 15-20L). According to a factory, scheduled lubrication has the potential to extend main bearing life from 8,000 hours to 15,000 hours and reduce annual maintenance cost by $12,000. If the lubrication is poor, when the vibration sensor detects the amplitude ≥4.5mm/s (normal value ≤1.2mm/s), equipment failure rate is 3.2 times greater.
Die maintenance should monitor wear and neutral, carbide die (hardness HRA 89-92) during pressing ibuprofen tablets life of about 1.5 million times, wear monitoring monthly ought to be below 0.005mm. Laser alignment equipment (accuracy ±0.01mm) quarterly calibration of upper and lower die reduces weight differential due to eccentric wear (±3% to ±1%). A company reduced downtime cost to $85,000 a year by using modular mold design (8 minutes/set replacement time).
Pressure system calibration ensures press quality. The main pressure sensor of the auto-tablet press is 3 months calibrated with a standard dynamometer (accuracy ±0.1kN) and pressure fluctuations are controlled within ±0.5kN. An example from a generic drug factory revealed that uncalibrated equipment produced the tablets with a hardness deviation of ±12% (norm ±5%), leading to a batch recall loss of $240,000. Servomotor-driven pressure systems, such as Manesty Xpress 700, should check encoder signal error (threshold ±0.05%) every 6 months to prevent pressure curve distortion.
Control and electrical maintenance should be updated from time to time, PLC program is copied and verified for every 6 months, and temperature sensor (PT100 type) calibrates cycle is 12 months (≤±0.5℃). A production line did not update the software in a timely manner, and therefore there was a parameter confusion, tablet thickness increased unusually from 4.2mm to 5.8mm, and the whole batch of raw material worth $180,000 was wasted. Installation of a predictive maintenance system (e.g., SKF@ptitude) is recommended to provide 14 days’ advance warning of bearing failure based on vibration spectrum analysis, reducing unplanned downtime by 72%.
Regulation of the manufacturing environment To achieve maximum performance of the device, the automatic tablet press operating room should be 20-25 ° C (fluctuation ±1 ° C) temperature and 45%-55% (±5%) humidity. In one instance, high temperature (30 ° C) led to 40% decrease in viscosity of grease and 2.3-fold increase in wear rate of gearbox. The inclusion of a live environmental monitor, say the Vaisala M170, can be connected to the HVAC system to make adjustments automatically, improving the overall equipment efficiency (OEE) from 78% to 92%.
Spares management and staff training In a bid to restrict the operational risk, it is recommended that main spares such as punching dies (more than 3 sets) and pressure sensors (2 sets) be held in reserve and the fault repair time be minimized to 4 hours from 48 hours. One company implemented a “5-minute response” training course that reduced operator error rates from 1.2 to 0.3 per thousand hours, reducing yearly quality incident losses by $350,000. Provide periodic GMP compliance training (≥40 class hours annually) to ensure that cleaning, validation, data integrity, etc. are FDA 21 CFR Part 11 compliant.