Chitosan polymer as a coat of calcium alginate microcapsules loaded by non-steroidal antiinflammatory drug

In a trial to delay the release rate of diclofenac sodium from alginate coated microcapsules, the use of a copolymer was suggested. Mixtures of polymers can have a significant properties than that of individual polymer to achieve sustained release microcapsules. On considering the negative charge of alginate and its ability to form polyionic complexes with a lowered tendency of erosion at higher pH value, a cationic polymer was seeked. Chitosan [CS] was the one of choice due to the similarity of the saccharide structures of chitosan and alginate that offers greater interaction between the two polymers and stronger inter-chains reactions relative to that between alginate and branched polymers such as polylysine. The microcapsules prepared using 0.1 and 0.25% [CS] were spherical in shape while 0.4% [CS] formed microcapsules having rounded heads and tapered tails. The change in chitosan concentration had a non-significant effect on the particle size, the yield and the drug loading efficiency. The releaser ate of diclofenac sodium from microspheres showed a pH dependent profile and was affected by chitosan coating. The release rate of diclofenac sodium from chitosan coated alginate microcapsules at pH 7.4 was found to be faster than its release at pH 1.2. These results suggest this coating method to protect diclofenac sodium under acidic conditions and to permit a complete but controlled release of diclofenac sodium

Preparation, characterization and in-vitro release of controlled release ketorolac tromethamine cellulose acetate butyrate microspheres

The purpose of this study was to prepare and characterize controlled release ketorolac tromethamine microspheres. To achieve this goal, cellulose acetate butyrate microspheres loaded by ketorolac tromethamine were prepared by the emulsion solvent evaporation method. The prepared ketorolac tromethamine microspheres were evaluated for their production yields, particle size distribution, morphology, drug content and drug release characteristics. Thermal Gravimetric Analysis [TGA] were performed on the drug polymer systems in order to shed a light on the possibility of solid state changes of ketorolac tromethamine with CAB. A Box-Behnken design was selected for formulating ketorolac tromethamine microspheres with revolution per minute [X1], drug-polymer ratio [X2] and span 80 percent [X3] as independent variables. Three levels of the independent variables were used which equal to-1, 0 and +1 for the above design. The values of the corresponding variables were 500, 700 and 900 rpm for the machine speed; 1:1, 1:2 and 1:3 for drug-polymer ratio; 1%, 1.5% and 2% [w/w] for span 80 percent

Formulation and physicochemical characterization of piroxicam containing polymer films

Piroxicam is a potent nonsteroidal anti-inflammatory drug associated with many side effects when taken orally. An attention was paid in this work to formulate and characterize piroxicam containing polymer films for dermal use. The used polymers were Eudragit types namely Eudragit RL100, RS100, L100 and Eudragit S100. In this study, medicated films consisting of drug and carrier were prepared. The carrier consisted of one or two polymers. The physicochemical characterization was done by IR spectroscopy, DSC and X-Ray diffractometry for both piroxicam polymeric films and their corresponding physical mixtures as well as the untreated drug and polymer powders to investigate the drug polymer interaction. The results indicate presence of molecular interactions between piroxicam and both Eudragit L100 and Eudragit S100 and no interactions were found between piroxicam and Eudragit RL100 or Eudragit RS100. In-vitro drug release from Eudragit films was studied It is found that the drug release from hydrophilic polymers is faster than that from hydrophobic ones

Preparation and evaluation of diclofenac sodium-cellulose acetate microcapsules using solvent evaporation technique

The aim of this study was the preparation of diclofenac sodium microcapsules using cellulose acetate as a polymer and polyvinyl acohol as an emulsifying agent by solvent evaporation technique. Preliminary experiments were carried out to determine practically the volume range of both the external phase, the internal organic phase, the concentration range of emulsifier and the drug to polymer ratio. The prepared microcapsules were evaluated for their morphology and surface structure, average particle size, yield, drug loading efficiency, and their release pattern. The results of these trials revealed that diclofenac sodium-cellulose acetate microcapsules were successfully prepared applying the solvent evaporation technique. The characteristics of the produced microcapsules were highly affected by the different formulation parameters. Changing the polymer content didn't affect the morphology of the produced microcapsules. The microcapsules were discrete, spherical and freely flowing. The increase in the polymer amount increased the mean particle size and decreased the yield of the microcapsules due to the increase in the internal phase viscosity. The drug loading efficiency was significantly increased with the increase in methylene chloride-acetone volume. The condensed monolayer of polyvinyl alcohol was not achieved at concentrations below 0.5%. Above this concentration] the increase in polyvinyl alcohol content decreased both the mean particle diameter end the percentage yield of the microcapsules. The release of diclofenac sodium from cellulose acetate microcapsules was pH dependent. The drug was released faster in the alkaline medium compared to acidic medium

Evaluation of preoperative localization of parathyroid adenoma using [99m]tc-sestamibi scintigraphy as a single diagnostic modality for patients with primary hyperparathyroidism

This- study was designed to evaluate the diagnostic yield of Technetium-99m hexakis methoxyisobutylisonitrile [Tc-99m-MIBI] scintigraphy in patients with primary hyperparathyroidism [PHPT] for identification of the site of parathyroid adenoma compared versus operative and histopathological findings. The study included 23 cases with PHPT; 5 nales and 8 females with mean age of 56.5 +/- 10.3; range: 39-69 years. Preoperative scanning using [99m]Tc-sestamibi was done. All patients underwent surgical exploration after methylene blue transfusion. Imaging data were compared with intraoperative finding. All identified and excised glands were sent for histopathological examination. Preoperative sestamibi scan defined a case with mediastinal parathyroid gland and another active cervical gland in 2 patients with persistent and recurrent hypercalcaemia, respectively. Preoperative sestamibi scan defined 6 cases with single parathyroid adenoma in each case, while surgical exploration defined 7 parathyroid adenomata; 5 cases had solitary adenoma and one case had adenoma in 2 parathyroid glands both stained blue after methylene blue infusion. Thus, sestamibi scan defined solitary parathyroid adenomas with an accuracy rate of 83.3%. However, sestamibi scan defined 3 cases with adenoma in 2 parathyroid glands and 2 cases had adenoma in 3 glands. Surgical exploration defined adenoma that confirmed histopathologically in 9 glands of the 12 identified by sestamibi scan; 4 cases had 2 adenomas and one case had one solitary adenoma, the other 3 glands showed only hyperplasia without adenoma formation. Thus, sestamibi scan defined multiple parathyroid adenomos with an accuracy rate of 75%. It could be concluded that preoperative localization of parathyroid gland depending on preoperative sestamibi scan could identify ectopic active glands with accuracy 100% and active cervical glands with an overall accuracy rate of 79.2% and concomitant intraoperative methylene blue localization allowed detection of active glands missed by preoperative sestamibi scan