Inclusion Complexation in Sulfobutyl Ether Beta Cyclodextrin and Dispersion in Gelucire for Sustained Release of Nifedipine Employing Almond Gum

In the present research investigation, the utility of employing high dissolving forms of nifedipine for sustained release from matrix tablets with almond gum as major release retardant is explored. A poorly soluble BCS class II drug nifedipine is chosen as a model drug. Efforts were made to alter the dissolution characteristics of the drug before it is entrapped in the polymer matrix of almond gum. Inclusion complexation in sulfobutyl ether beta cyclodextrin or solid dispersion in gelucire (50/13) resulted in enhanced dissolution of nifedipine. The high dissolving forms are characterized by x-ray diffraction, differential scanning calorimetry and infra-red spectroscopy. The matrix tablets prepared employing the high dissolving forms exhibited satisfactory characteristics such as hardness, friability, swelling index. The drug release is found to be slow and spread over a period of 12 hours and the release could be modified with changes in nature of high dissolving form and the proportion of almond gum as the major release retardant. Employing high dissolving forms in matrix tablets of almond gum is found to be a novel approach in obtaining slow and complete release of poorly soluble drug such as nifedipine. Keywords:  sulfobutyl ether beta cyclodextrin, solid dispersion, nifedipin

Rupture of Extra-Corporeal Circuit Tubing During Cardiopulmonary Bypass

Roller pumps are widely used for cardiopulmonary bypass in developing nations by virtue of proven safety during several years of institutional use and cost effectiveness. However, careful adjustment of roller occlusion is needed because they are known to cause spallation, tubing wear, and the occasional incident of rupture of tubing in the extracorporeal circuit. Rupture of polyvinylchloride tubing in the pump raceway during repair of a ventricular septal defect in a 4-year-old child is discussed. The event was managed by exclusion and replacement of the defective tubing during a short period of arrest. Use of an inappropriate boot pump and failure to detect its inclusion in the bypass circuit was a significant departure from protocol. However, because occlusion settings and duration of perfusion were within acceptable limits, a manufacturing flaw could also have contributed to tubing failure, and the event may or may not have been averted by the use of larger tubing. In conclusion, this incident reiterates the need for adherence to established protocol during assembly of the pump and draws attention to the fact that tubing integrity is not a guarantee and vigilance is warranted to handle its failure