Stability studies on Ghanvati formulated from Psidium guajava Linn. leaf decoction

We developed a formulation (tablet, Ghanvati), from Psidium guajava L. leaf decoction and assessed its stability using standard guidelines. The organoleptic and physicochemical analysis of the leaves and prepared extract was undertaken. The tablets were subjected to friability, the dimensions were measured and its stability [hardness, disintegration, and loss on drying (LOD)] tested on 0-day and the end of 3, 6, and 12 months at ambient, intermediate and accelerated conditions as per International Council for Harmonization Q1 (R2) guidelines. Simultaneously, representative phytocompounds (gallic acid, epigallocatechin gallate, ellagic acid, and quercetin) were quantified using high performance liquid chromatography. The organoleptic, physicochemical, and friability were within specified limits. Stability studies indicated significant increase in % LOD values affecting the hardness of the tablet. With respect to phytoconstituents, epigallocatechin gallate and ellagic acid showed increase in concentration at 12 months at ambient (6.524 ± 0.93 and 8.03 ± 0.75 μg/mg, respectively) and intermediate conditions (5.53 ± 0.34 and 8.267 ± 0.87 μg/mg, respectively) compared to 0-day (4.03 ± 0.66 and 0.513 ± 0.08 μg/mg, respectively). In contrast, compared to the 0-day values (16.0 ± 0.14 and 0.8154 ± 0.13 μg/mg, respectively), the concentration of gallic acid and quercetin decreased under ambient (14.44 ± 0.99 and 0.4 ± 0.06 μg/mg, respectively) and intermediate (8.6 ± 0.69 and 0.324 ± 0.3 μg/mg, respectively) conditions. Thus, despite stability in terms of hardness and disintegration time, the hygroscopicity and chemical variability with time of the prepared Ghanvati warrant the need for alternative approaches to improve stability.