Evaluation of polyoxyethylene homopolymers for buccal bioadhesive drug delivery device formulations

Our objective was to evaluate the application of polyoxyethylene homopolymers in buccal bioadhesive drug (BBD) delivery device formulations. The bioadhesive strength of four different molecular weight (MW) polyoxyethylene polymers was measured by Instronâ tensile tester using glass plate and bovine sublingual tissue as substrate surfaces. Several BBD device formulations containing polyoxyethylene polymer (MW 7,000,000) were prepared by direct compression and compression molding processes. The prepared BBD devices were evaluated for their elasticity, in vitro adhesion and drug release characteristics. The in vivo bioadhesion characteristics of a placebo compression molded device were examined in 3 adult healthy male beagle dogs. The bioadhesive strength of polyoxyethylene polymers appeared to be directly related to their molecular weights. When bovine sublingual mucosa or a glass plate was used as model mucosal substrate surface, the rank order of bioadhesive strength of different molecular weight polyoxyethylene polymers was similar. The bioadhesive strength of devices prepared by the compression molding process was greater than those prepared by direct compression, but the kinetics of drug release were independent of the process used for the preparation of the devices. The drug release and the bioadhesive strength of the similarly prepared device formulations appeared to be dependent on the drug:polymer ratios. The elasticity of the BBD devices prepared by compression molding was improved by the inclusion of polyisobutylene polymer in the formulations. When adhered to the oral cavity of the dogs, the compression molded placebo BBD device exhibited adhesion for at least 4 hours and appeared to show no signs of local irritation. In conclusion, BBD devices containing polyoxyethylene polymer (MW 7,000,000) can be prepared by direct compression or compression molding process in order to provide controlled drug release to the oral cavity while maintaining appropriate bioadhesive characteristics.     

Large mediastinal tumor in a neonate: an anesthetic challenge

Mediastinal tumors pose a grave risk of cardiopulmonary complications during the perioperative course, particularly in neonates and small children. These tumors can cause displacement and compression of vital thoracic structures such as the tracheobronchial tree, the heart, and the great vessels. Catastrophic complications often occur during induction of anesthesia, use of muscle relaxants, positioning, and at the time of extubation. We present our experience of anesthetic management of a neonate with a mediastinal mass who had features of both airway and vascular obstruction.     

Dissipation of Quinalphos in Kinnow Mandarin Fruits under Subtropical Conditions of Punjab,India

Quinalphos residues were studied separately in the pulp and rind of kinnow mandarin fruits by following a standardized methodology and estimated on gas liquid chromatograph (GC) by employing nitrogen phosphorus detector. Following application of quanilphos (Ekalux 25EC) at 10.0 and 20.0 mL per tree (per 5 L of water) on kinnow mandarin fruits at both these dosages were found to be 0.05 and 0.16 mg/kg, respectively. These initial deposits were found to be less than its maximum residue limit (MRL) of 0.25 mg/kg. The corresponding values in the rind were found to be 0.65 and 1.64 mg/kg, respectively. These residue levels in the rind dissipated below the MRL in 5 and 15 days, respectively. The half-life value for quanilphos in the rind at single and double dosages were found to be 3.2 and 4.0 days, respectively. Low dissipation rate of quanilphos in the rind may be attributed to the fibrous nature of the peel where the insecticide can be adsorbed, high moisture content and oil based nature of the rind. The results clearly show that quanilphos does not penetrate into the pulp of the kinnow mandarin and the fruit is safe for consumption even after one day of the application at both these dosages.     

A rare case of survival from primary amebic meningoencephalitis

Primary amebic meningoencephalitis (PAM) is a rare and fatal disease of central nervous system (CNS) caused by Naegleria fowleri, an ameba found in soils and warm waters. It enters the CNS after insufflation of infected water by attaching itself to the olfactory nerves. The infection is usually difficult to diagnose and has a poor prognosis. The present case is one such case in which CSF examination led us to the diagnosis of PAM and finally to a favorable outcome when treated with Amphoterracin B and antibiotics.