Co-milling of telmisartan with poly(vinyl alcohol) – An alkalinizer free green approach to ensure its bioavailability

[Display omitted] •Telmisartan and poly(vinyl alcohol) were co-milled in a planetary micro mill.•The size and physical state of the telmisartan particles were depended on process parameters used.•Dissolution of telmisartan from CG1 tablet was 96.57±2.02% at 30min.•Bioavailability of CG 1 tablet (93.92±12.84%) was comparable to innovator’s product (Micardis®).•Absence of use of any of the alkalinizer/s in the formula, ensured the gastro environmental friendliness of the product. The aim of this study was to enhance the dissolution and bioavailability of telmisartan (TLM), a poorly water soluble drug by co-milling approach. Physical mixtures of TLM and poly(vinyl alcohol) (PVA) were co-milled in a planetary micro mill in a dry condition by varying process parameters such as drug to polymer weight ratio, ball-to-powder weight ratio, and rotational speed. The co-milled products offered cumulative percentage dissolution of TLM above 75% in 30min (CG 1 and CG2). These samples were characterized using field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and Raman spectra analysis. Well-dispersed acicular shaped particles of TLM were observed in co-milled products. A mixture of crystalline and amorphous TLM with a particle size less than 1μm was present in CG1. The particle size of TLM observed in CG2 was less than 2μm. In addition to crystalline and amorphous form of TLM, defective/disordered crystals of TLM were also present in CG 2. Therefore, CG2 tablets exhibited poor stability. CG 1 tablets were found to be stable under accelerated stability test conditions. The relative bioavailability of TLM of CG 1 containing tablets in comparison with Micardis® was 93.92±12.84% (in rabbits). Thus, co-milling of TLM with PVA proves to be a promising “alkalinizer free green approach” to ensure the dissolution and bioavailability of poorly water soluble TLM.