Solidified Reverse Micellar Solution (SRMS)-Based Indomethacin Sustained-Release Tablets: Formulation and &lt;i&gt;In vitro&lt;/i&gt; Evaluation

Sa Chime,Gc Onunkwo,Aa Attama,Iv Onyishi

doi:10.4314/tjpr.v13i2.7

Abstract

Purpose: To formulate and evaluate sustained-release indomethacin tablets based on solidified reverse micellar solution (SRMS).Methods: SRMS consisting of mixtures of phospholipid (Phospholipon® 90H) and triglyceride (Softisan® 154) were prepared in the ratios of 1:1, 2:1 and 1:2, respectively. SRMS-based tablets containing 75 mg of indomethacin each were prepared using a validated plastic mould. The physicochemical properties of the tablet formulations were studied. In vitro release study was carried out in simulated intestinal fluid (SIF, pH 7.5).Results: The results showed that the physicochemical properties of the tablet formulations were significantly affected by the composition/ratio of the lipid matrix used (p < 0.05). Tablet hardness ranged from 5.00 ± 0.39 to 5.60 ± 0.36 kgf for tablets formulated with SRMS 1:2 and 2:1 (N3 and N2), respectively. The tablets exhibited friability of < 1 % (p < 0.05). Erosion time in SIF ranged from 124.0 ± 0.5 to 180.0 ± 1.1 min while drug release from the tablets reached a maximum in 8 – 11 h for all thebatches.Conclusion: Indomethacin tablets based on SRMS exhibited good sustained-release properties and can be further developed to achieve once daily administration for improved patient adherence to therapy.Keywords: Solidified reverse micellar solution, Phospholipid, Triglyceride, Indomethacin, Sustained release.

Highlights

Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) with prominent anti-inflammatory, analgesic and antipyretic properties similar to those of the salicylates
Indomethacin DSC curves showed a melting peak at 162.2 oC while those of the lipid matrices showed that the structuring of Softisan® 154 with P90H produced matrices with low enthalpies
Indomethacin tablets formulated with lipid matrix (SRMS) 2:1 (N2 tablets) had the highest erosion time of 180.40 ± 1.06 min

Summary

INTRODUCTION

Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) with prominent anti-inflammatory, analgesic and antipyretic properties similar to those of the salicylates. Solidified reverse micellar solution (SRMS) consisting of phospholipid and solid lipid such as Softisan® 154, a completely hydrogenated palm oil, transforms into a lamellar mesophase after melting on contact with water This transformation enables controlled release of solubilized drugs. The required amount of the active ingredient that would give 75 mg of indomethacin per tablet was transferred into the melted lipid matrix in the crucible with stirring until a homogenous mix was obtained. The test was carried out for each batch of the tablet using a beaker containing 500 ml of SIF (pH 7.5) maintained at 37 ± 1 oC. The erosion time was taken as the time taken for the tablet to change in shape and erode appreciably This test was repeated three times for each batch and the mean erosion time was determined.

RESULTS

CONCLUSION

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