In-vitro and in-vivo evaluation of sustained-release suppositories containing theophylline microspheres

The sustained release microspheres of theophylline were formulated using non-solvent addition technique. The in-vitro dissolution of the drug from the fabricated microspheres that having size ranges of 300-600, 600-800 and 800-1000 [micro]m was tested The release of theophylline was extended over 8 hrs and it was found that the drug release decreased nonsignificantly as the particle size increased [p>/=0.05]. incorporating theophylline-containing microspheres into suppository formulation using polyethylene glycol base resulted in a slight increase in dissolution rate, but still in a sustained release pattern over 8 hrs. In-vivo study of the prepared suppositories on beagle dogs revealed that the peak of theophylline serum concentration C[max] [mean +/- S.D] was 11.1+0.3 [micro]g/mL. It was also found that AUC [0-24hrs] value averaged 154.7 +/- 20.3 [micro]g-h/ml. The median peak time [T[max]] was 3.0 hrs and MRT was 13 hrs indicating a sustained effect

Formulation and evaluation of rofecoxib capsules

Rofecoxib [ROF] is an analgesic, antipyretic and anti-inflammatory drug. It is a selective inhibitor of cyclooxygenase enzyme [Cox-2 inhibitor]. The aim of this work was to formulate and evaluate ROF capsules and compare them with a commercial ROF product. The ROF capsules were prepared using different excipients namely: Sta-Rx starch 1500, cellactose, anhydrous lactose and tablettose. Compatibility of the drug with the used excipients was studied by differential scanning calorimetry. The effect of cogrinding of ROF with either PVP 40000 or Avicel PH 101 in the ratio of 1:5 w/w on the drug release from the prepared capsules was also studied. Differential scanning calorimetry and x-ray diffraction studies showed reduction in crystallinity or conversion of the drug to an amorphous form upon grinding with either PVP 40000 or Avicel PH 101 respectively. All formulae of ROF capsules complied with the USP XXV requirements for uniformity of dosage units. Formulae No. 6 and 7 containing ground mixture of the drug with either PVP 4000 or Avicel PH 101 in a ratio of 1:5 drug to carrier and Sta-Rx starch 1500 as diluent gave a higher dissolution rate of ROF [t[50%] = 5 and 9 min., respectively] in comparison with the commercial ROF product Rhumacure [t[50%] = 25 min.] Moreover; the anti-inflammatory activity was studied in rats using paw-edema method and the results obtained were analyzed using ANOVA test at the level of significance [P