Effect of wet mass on dextromethorphan hydrobromide matrix pellets

Dextromethorphan hydrobromide (DM) sustained release matrix pellets containing 10% w/w drug were prepared by an extrusion/spheronization technique. The effect of mixing different concentrations of ethyl cellulose (EC), hydroxypropyl methylcellulpse (HPMC K10), and Carbopol 934 with Avicel PH101 on the rheological properties of pellet wet mass was evaluated using mixer torque rheometry (MTR). The prepared pellets were characterized for size, drug content, and in-vitro DM release rate. The results showed that increasing the concentration of the hydrophobic polymer (EC) with Avicel PH101 decreased wet mass consistency, represented by mass mean line torque. Lower binder ratio was required for optimum wet massing, while mixing with swellable polymers (HPMC and Carbopol) caused a noticeable increase in both mean line torque and binder ratio. Combinations of HPMC and Carbopol at higher concentrations resulted in controlled in vitro release of DM from the prepared pellets. Furthermore, mathematical treatment of the in vitro release data of DM from the prepared pellets showed that all formulations except those containing 5% Carbopol plus 5% HPMC (F10) follow first order release. n values of these formulation were in the range of 0.09-0.40, which support an anomalous non-Fickian release.

Normal-phase LC method for simultaneous analysis of pseudophedrine hydrochloride, dextromethorphan hydrobromide, chlorpheniramine maleate, and paracetamol in tablet formulation

A simple, precise, and accurate method and validated for the analysis of pseudophedrin hydrochloride, dextromethrophan hydrobromide chlorpheniramine maleate, and paracetamol in tablet formulations. The method has shown adequate separation of the four ingredients from each other. Separation was achieved on a silica column [5 micro m, 125 X 4,6 mm inner diameter] using a mobile phase consisting of methanaol/ammonium dihyddrogen phosphate buffer [90:10, v/v] at a flow rate of 1.0 ml/min and UV detection at 220 nm. This new method is validated in accordance with USP requirements for new methods for assay determination, which include accuracy, precision, selectivity, linearity and range, probustness and ruggedness. The current method demonstrates good linearity over the range of 0.15-0.45 mg/ml of pseudophedrine hydrochloride with r[2] of 0.996, and in the range of 0.075-0.225 mg/ml of dextromethorphan hydrobromide with r[2] of 0.992, and in the range of 0.01-0.03 mg/ml of chlorpheniramine maleate with r[2] of 0.994, and in the range of 0.25-0.75 mg/ml of paracetamol with r[2] of 0.991. The average recovery of the method is 99.7%, 98.1%, and 99.2% for pseudophedrine hydrochloride, dextromethorphan hydrobromide, chlorpheniramien maleate, and paracetamol, respectively. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operator has proven that the method is robust and rugged

Stability indicating methods for the quantitative determination of pseudoephedrine HCl and guaifenesin and dextromethorphan HBR in a cough syrup using HPLC

The determination of three active ingredients in a multicomponent pharmaceutical product by HPLC using two columns is reported. Guaifenesin and dextromethorphan HBr were separated and quantitated simultaneously in a cough syrup using an isocratic reversed phase system. The mobile phase was 45% [v/v] aqueous methanol with ammonium formate as buffer [PH 4.3]. the range of concentrations used in the determination of guaifenesin and dextromethorphan HBr were 202-363 mg/100ml and 30-54 mg/100 ml, respectively. A separate method was developed for the determination of pseudoephedrine HCI using a normal phase system. The mobile phase was 80% [v/v] aqueous ethanol with ammonium acetate as buffer [pH 7.3]. the range of concentrations used in the determination of pseudoephedrine HC1 was 60-108 mg/100 ml. Both methods proved to be repeatable, reproducible and stability indicating