Application of a quality-by-design approach for utilizing sodium stearyl fumarate as a taste-masking agent in dextromethorphan hydrobromide orally disintegrating tablets.

Orally dissolving tablets (ODTs) represent one of the recent advances in drug delivery. The foremost objective of this study was to optimize the utilization of lubricant sodium stearyl fumarate in the preparation of dextromethorphan hydrobromide ODTs with enhanced taste-masking properties. The simple blending of sodium stearyl fumarate with the powder bed would result in taste-masking through physical adsorption of the lubricant particles on the drug particles. A randomized 32 full factorial experimental design was used to characterize the relationship between lubricant ratio (X1), mixing time (X2), and the tablet properties. The tablets were assessed for friability, hardness, disintegration time, and in-vitro dissolution. All tablets showed hardness within the range of 3.0-3.7 kp, and the % loss in friability test was less than 1.1%. The in-vitro disintegration time ranged between 9 and 25 s. An in-vitro drug release study of the prepared ODTs showed that more than 90% of the drug was released within 30 min. A palatability test of the optimized formula conducted in human volunteers showed acceptable taste and mouthfeel with in-vivo disintegration time of 17 s. Thus, results obtained convincingly showed successful fast disintegration of the prepared tablets and acceptable palatability when using sodium stearyl fumarate as a taste masking agent.

Formulation and pharmacokinetics of multi-layered matrix tablets: Biphasic delivery of diclofenac.

The rapid availability of the drug at the site of action followed by maintaining its effect for a long period of time is of great clinical importance. Thus, the purpose of the present study was to prepare and evaluate multi-layered matrix tablets of diclofenac using Eudragit RL/RS blend to achieve both immediate and sustained therapeutic effects. Diclofenac potassium (25 mg) was incorporated in an outer immediate release layer to provide immediate pain relief whereas diclofenac sodium (75 mg) was incorporated in the inner core to provide extended drug release. Wet granulation was employed to prepare the inner core of the tablets that were further layered with an immediate release drug layer in the perforated pan coater. The in-vitro and in-vivo performance of the developed formulation was compared with the marketed products Voltaren® SR 75 mg and Cataflam® 25 mg. The in-vitro drug release of the prepared formulation showed similarity (f2 = 66.19) to the marketed product. The pharmacokinetic study showed no significant difference (p > 0.05) in AUC0-24 and Cmax between the test and reference formulations. The AUC0-24 values were 105.36 ± 83.3 and 92.87 ± 55.53 µg h/ml whereas the Cmax values were 11.25 ± 6.87 and 12.97 ± 8.45 µg/ml, for the test and reference, respectively. The multi-layered tablets were proved to be bioequivalent with the commercially available tablets and were in agreement with the observed in-vitro drug release results. Stable physical characteristics and drug release profiles were observed in both long term and accelerated conditions stability studies.

Investigation of in situ gelling alginate formulations as a sustained release vehicle for co-precipitates of dextromethrophan and Eudragit S 100.

Alginate vehicles are capable of forming a gel matrix in situ when they come into contact with gastric medium in the presence of calcium ions. However, the gel structure is pH dependent and can break after gastric emptying, leading to dose dumping. The aim of this work was to develop modified in situ gelling alginate formulations capable of sustaining dextromethorphan release throughout the gastrointestinal tract. Alginate solution (2 %, m/m) was used as a vehicle for the tested formulations. Solid matrix of the drug and Eudragit S 100 was prepared by dissolving the drug and polymer in acetone. The organic solvent was then evaporated and the deposited solid matrix was micronized, sieved and dispersed in alginate solution to obtain candidate formulations. The release behavior of dextromethorphan was monitored and evaluated in a medium simulating the gastric and intestinal pH. Drug-polymer compatibility and possible solid-state interactions suggested physical interaction through hydrogen bonding between the drug and the polymer. A significant decrease in the rate and extent of dextromethorphan release was observed with increasing Eudragit S 100 concentration in the prepared particles. Most formulations showed sustained release profiles similar to that of a commercial sustained-release liquid based on ion exchange resin. The release pattern indicated strict control of drug release both under gastric and intestinal conditions, suggesting the potential advantage of using a solid dispersion of drug-Eudragit S 100 to overcome the problem of dose dumping after the rupture of the pH dependent alginate gels.