Jornal de Bioequivalência e Biodisponibilidade

Abstrato

Comparative Study of Sustained Release Potential of a Newly Isolated Senna tora Seed Galactomannan with Commercially Available Polymers

Harshal A Pawar and Lalitha KG

The objective of the present research work was to study sustained release behavior and potential of galactomannans alone, in combination with xanthan gum and their comparison with commercially available semisynthetic hydrophilic polymer. Once daily sustained release matrix tablets of losartan potassium were prepared using isolated Senna tora seed galactomannan, other galactomannan containing commercially available gums (guar gum and locust bean gum) alone and in combination with xanthan gum. The influence of different concentrations and nature of polymer was studied. The tablets were prepared by wet granulation method and evaluated for physical characteristics like hardness, weight variation, friability and drug content. The in-vitro drug release profile of matrix tablets prepared using galactomannan containing gums were compared with matrix tablet prepared using commercially available and widely used semi-synthetic polymer (Methocel K 100 M) at the same concentration level. All the physical characters of the fabricated tablet were found to be within acceptable limits. Drug-excipient interaction was evaluated by differential scanning calorimetry and FTIR. There was no drug excipient interaction. Galactomannans isolated from Senna tora seeds showed better sustained release potential as compared to other galactomannans used in the study when used alone. The tablets prepared using combination of guar gum and xanthan gum (F11) with drug to polymer ratio of 1:4 exhibited greater swelling index and better sustained release potential than other galactomannans in combination with xanthan gum. Hence, the batch F11 was considered as optimized formulation. Formulation F11 showed no change in physical appearance and dissolution profile upon storage at 40°C/75 % relative humidity for six months. Compared to conventional tablets, release of losartan potassium from these matrix tablets was prolonged, leading to achieve an effective therapy with low dosage of the drug, to reduce the frequency of medication. Formulation F11 was found stable at accelerated conditions 40 ± 5°C / 75% RH for a period of 6 months. The pharmacokinetic parameters Cmax, Tmax, and AUC of developed sustained release tablets were found to be improved with significant difference when compared with conventional immediate release tablets.