Lubricating Properties of Co-processed Coconut Oil in Paracetamol Tablets Formulation

Objective: Lubricants are additives which reduce friction and so essential components of drug formulation. This piece of work was initiated to evaluate coconut oil as a co-processed lubricant in the formulation and compression of paracetamol tablets in comparison with magnesium stearate-talc as standard lubricant.

Methods: Various concentrations 0.5, 1.5, 2.0 and 2.5% w/w lubricant mixtures of magnesium stearate-talc (MT), coconut magnesium stearate-talc (CMT), magnesium stearate (M), coconut oil alone (C) respectively; and without lubricant (None) which served as control were thoroughly mixed with granules (200 mg) prepared from the basic formula for paracetamol tablets which contained 85% w/w, 5% w/w and 10% w/w of paracetamol powder, corn starch and lactose respectively. The mechanical properties of tablets produced were evaluated using crushing strength, friability and crushing strength -friability ratio while the release properties of tablets were evaluated using disintegration and dissolution tests.

Results: Granules lubricated with coconut oil co-processed with magnesium stearate had excellent flow. The crushing strength obtained for all the paracetamol tablets had acceptable values ranging from 4.82 to 6.85 kgf except for tablets lubricated with coconut oil alone. Generally, as the crushing strength values increased the friability decreased. Friability values for all the tablets generally decreased with increasing tablet lubricant concentrations of 2.0% w/w and 2.5% w/w though falling within range considered for conventional tablets. The disintegration time increased with increase in lubricant concentration as all the tablets had acceptable values. Tablets lubricated with coconut oil mixed with magnesium stearate-talc showed the highest CSFR/DT ratio. As the concentration of lubricant increased, there was a general decrease in the rate and extent of the drug release from the formulation.

Conclusion: Coconut oil is an effective lubricant which can be processed with magnesium stearate and talc for an effective lubrication of granules before compression into pharmaceutical tablets.