The in vitro dissolution rates of 5 and 10 mg nifedipine capsules from eight suppliers were measured in simulated gastric fluid using the rotating paddle apparatus. A total of fourteen products were tested and the performance was found to be satisfactory for all products (> 80% dissolution in 20 min).

A study was carried out using high performance liquid chromatography (HPLC) to determine the chemical stability of amoxycillin and potassium clavulanate in 250/62 co-amoxyclav oral suspension (Augmentin), stored at room temperature (RT, 20 degrees C) and 8 degrees C over a period of 11 days. The suspension was judged to be acceptable if its components maintained at least 90% of their label concentrations. During the test period, the amoxycillin component was found to be more stable than the clavulanate. Amoxycillin was stable for 7 days at both temperatures. Potassium clavulanate maintained at least 90% of its initial concentration for 7 days at 8 degrees C but showed more than 40% degradation in the same time period at RT. For potassium clavulate the shelf-life, or time taken for the original concentration to drop to 90% of its value (t90) at RT was found to be 2 days.

This paper describes an accurate, specific and sensitive high-performance liquid chromatographic (HPLC) method for the determination of ciprofloxacin in small samples (0.5 ml). The samples, after pretreatment by solvent extraction, were eluted on a reversed-phase column and detected by an ultraviolet detector. The results obtained on patient samples are presented.

The in vitro dissolution rates of 10- and 20-mg piroxicam capsules from different suppliers in the U.K. were measured in simulated gastric fluid using rotating basket apparatus. Seven brands were tested and all were found to be satisfactory with at least 75% dissolution in 45 min.