Advances in dissolution instrumentation and their practical applications

Potential Application of USP Paddle and Basket Dissolution Methods in Discriminating for Portioned Moist Snuff and Snus Smokeless Tobacco Products

The focus of the study was to develop discriminatory dissolution methods for portioned snus and moist snuff sub-categories of smokeless tobacco products (STPs) using USP basket and paddle apparatuses. Skoal Classic Wintergreen (SCW) and CORESTA CRP1.1 pouches were used as test products. The dissolution was performed at 10, 20, 30, 40, and 50 rpm basket or paddle speed in 500 ml artificial saliva pH 6.8. The products were also characterized for assay, pH, particle size, and loss on drying. The dissolution profiles were evaluated for amount/% of nicotine dissolved, time to reach plateau, and profiles comparison by f2 and f1 factors. The nicotine assay was 13.3 ± 0.2 and 7.6 ± 0.1 mg/pouch for SCW and CRP1.1, respectively. The nicotine dissolved in 30 min from SCW and CRP1.1 were 38.4-81.8 and 37.6-88.1, and 50.5-64.9 and 72.3-92.1% by paddle and basket methods, respectively. The f2 and f1 values were ≤ 39.2 and ≥ 42.1 and ≤ 43.2 and ≥ 34.1 for basket methods and paddle methods. RSD were less than 20% at all points of dissolution profiles, and dissolution plateau were achieved in 30 min at some of the tested conditions. In summary, dissolution methods based on basket and paddle can be used as a performance test for STPs.

Development of a Dissolution Method for Gliclazide Modified-Release Tablets Using USP Apparatus 3 with in Vitro-in Vivo Correlation

Gliclazide (GLZ) is a second generation hypoglycemic drug used for the treatment of Type 2 diabetes mellitus. The low solubility of GLZ has been described as the rate limiting step for drug dissolution and absorption, thus a prediction of its in vivo behavior based on a discriminative dissolution test should lead to a relevant in vitro-in vivo correlation (IVIVC). The aim of this study was to develop a dissolution method for GLZ modified-release (MR) tablets using an United States Pharmacopeia (USP) apparatus 3 through its evaluation by an IVIVC analysis. Various dissolution parameters were evaluated to establish an in vitro method for GLZ tablets. The final dissolution conditions, referred to as method 3, utilized a 400 µm mesh and 30 dips per minute over a total period of 10 h that included 1h in HCl media (pH 1.2), 2h in acetate buffer solution (pH 4.5), 1 h in phosphate buffer solution (PBS; pH 5.8), 5h in PBS (pH 6.8) and finally 1h in PBS (pH 7.2). The calculated point-to-point IVIVC (R²=0.9970) was significantly greater than other methods. The robustness of method 3 suggests it could be applied to pharmaceutical equivalence studies and for quality control analyses of GLZ.

Development of In Vitro-In Vivo Correlation/Relationship Modeling Approaches for Immediate Release Formulations Using Compartmental Dynamic Dissolution Data from "Golem": A Novel Apparatus

Different batches of atorvastatin, represented by two immediate release formulation designs, were studied using a novel dynamic dissolution apparatus, simulating stomach and small intestine. A universal dissolution method was employed which simulated the physiology of human gastrointestinal tract, including the precise chyme transit behavior and biorelevant conditions. The multicompartmental dissolution data allowed direct observation and qualitative discrimination of the differences resulting from highly pH dependent dissolution behavior of the tested batches. Further evaluation of results was performed using IVIVC/IVIVR development. While satisfactory correlation could not be achieved using a conventional deconvolution based-model, promising results were obtained through the use of a nonconventional approach exploiting the complex compartmental dissolution data.