Formulation, development and evaluation of patient friendly dosage forms of metformin, Part-I: Orally disintegrating tablets

Metformin hydrochloride is an orally administered antihyperglycemic agent, used in the management of non-insulin-dependant (type-2) diabetes mellitus. Difficulty in swallowing (dysphagia) is common among all age groups, especially in elderly and pediatrics. Unfortunately, a high percentage of patients suffering from type-2 diabetes are elderly people showing dysphagia. In this study, orally disintegrating tablets were prepared using direct compression and wet granulation method. First, the tablets of metformin were prepared using starch RX1500 and microcrystalline cellulose by direct compression. The tablets showed erosion behavior rather than disintegration. Then lactose was incorporated which created pores to cause burst release of drug. But these tablets did not give good mouth feel. Thus, Pearlitol SD 200 (spray dried mannitol) was used to prepare tablets by wet granulation (10% polyvinylpyrrolidone in Isopropyl alcohol as binder). The optimized batches of tablets (LMCT3 and MP13) not only exhibited desired mouth feel but also disintegration time, in vitro dispersion time, water absorption ratio, and in vitro drug release. All the batches contained 15% starch 1500 and 4% of croscarmellose sodium. The optimized batches prepared by direct compression and wet granulation showed 85% drug release at 4 min and 8 min, respectively. The strong saline and slight bitter taste of the drug was masked using nonnutritive sweetener and flavor.

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