ABSTRACT
Background: Eptifibatide [Integrilin] is an intravenous [IV] peptide drug that selectively inhibits ligand binding to the platelet GP IIb/IIIa receptor. It is an efficient peptide drug, however has a short half-life. Therefore, antithrombotic agents like eptifibatide are required to become improved with a protected and targeted delivery system such as using nano-liposomes to the site of thrombus
Objectives: The goal in the present report was to optimize encapsulation efficiency of the eptifibatide into Arg-Gly-Asp [RGD]-modified nano-liposomes [RMNL]. As well, it was intended to evaluate the effect of sodium lauryl sulfate [SLS] on drug release
Materials and Methods: The effect of five independent variables including number of freeze/thawing cycles, concentration of eptifibatide, 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC], cholesterol, and dipalmitoyl-GRGDSPA peptide on drug entrapment efficiency [DEE] was investigated using response surface methodology [RSM]. The effect of different concentrations of SLS on encapsulation and drug release from RMNL was also investigated. The size and morphology of RMNL were characterized using transmission electron microscopy [TEM]
Results: The maximum DEE [38%] was obtained with 7 freeze/thawing cycles, 3.65 micro moL eptifibatide, 7 mM DSPC, 3 mM cholesterol, and 1 mM dipalmitoyl- GRGDSPApeptide. SLS has significantly increased the drug release from RMNL, although its effect on encapsulation efficiency was not significant
Conclusions: The optimization of the formulations for valuable and expensive peptide drugs is essential to have the maximum encapsulation efficiency and the minimum experiments
ABSTRACT
Background and Objectives: In situ gel formation of Glycerol Monooleate [GMO] has been utilized to release many drugs. The aim of this research was to optimize, and in-vitro characterization of the controlled release and formulation of the matrices containing Olanzapine [OZ], GMO and Polyethylene glycol [PEG 300]
Methods and Materials: Response surface methodology [RSM] is a combination of mathematical and statistical techniques. In this study, Design-Expert software with Box-Behnken response surface methodology has been used to determine the relationships between variables and responses. GMO/water weight ratio [w/w] different and PEG 300/GMO [w/w] were in the range of 2-4% and 2-6% respectively. Percentage of loading; and release at 12 th and 168 th hr were calculated. In-vitro release studies of OZ from prepared gels were conducted in PBS [pH 6.8] and then analyzed by spectrophotometer at 265 nm
Results: The optimum formulation was obtained at weight ratio of water/GMO [w/w] and PEG [300]/GMO [w/w] at 0.28 and 0.2 respectively, and percentage of OZ was at 4%. The observed and predicted values for EE % were 86.8 %, 90.31% respectively those parameters for release at 12th hr were 16.1% and 15% and for release at 168th hr, were 59.8 % and 63.56% respectively
Conclusion: In this study we performed kinetic release profile of OZ with several models, from which Higuchi model showed the best fitting and correlation
ABSTRACT
The main objective of this study was to prepare colon-specific pellets of budesonide, using pectin as film coating. Pellet cores of budesonide were prepared by extrusion / spheronization technique. Pectin, in different ratios was combined with Eudragit RS30D, Eudragit NE30D or Surelease to produce film coating. The dissolution profiles of pectin coated pellets were investigated in pH of 1.2 [2 h], pH of 7.4 [4 h] and pH of 6.8 in the absence as well as presence of rat cecal contents [18 h]. Finally the selected formulation was evaluated on trinitrobenzenesulfonic acid [TNBS] induced ulcerative colitis in rat model, in comparison with conventional UC treatments. The dissolution profiles of pectin coated pellets showed that the release of budesonide in presence of rat cecal content depended on adjuvant polymer, the ratio of pectin to polymer and film thickness. Coated pellets, prepared out of pectin and Surelease at a ratio of 1:3 at coating level of 35% [w/w], could increase budesonide release statistically in presence of rat cecal content, while they released no drug in pH of 1.2 and 7.4. Animal experiments revealed the therapeutic efficacy of pectin/Surelease-coated pellets of budesonide in alleviating the conditions of TNBS-induced colitis model as reflected by weight gain, as well as improvement of clinical, macroscopic and microscopic parameters of induced colitis. This confirmed the ability of the optimized formulation for targeted drug delivery of budesonide to colon