Precipitation of a Poorly Soluble Model Drug during In Vitro Lipolysis: Characterization and Dissolution of the Precipitate

2010 ◽  
Vol 99 (12) ◽  
pp. 4982-4991 ◽  
Author(s):  
Philip J. Sassene ◽  
Matthias M. Knopp ◽  
Janne Z. Hesselkilde ◽  
Vishal Koradia ◽  
Anne Larsen ◽  
...  
2010 ◽  
Vol 60 (4) ◽  
pp. 373-385 ◽  
Author(s):  
Tina Ukmar ◽  
Odon Planinšek

Ordered mesoporous silicates as matrices for controlled release of drugs Interest in and thereby also development of ordered mesoporous silicates as drug delivery devices have grown immensely over the past few years. On hand selected cases from the literature, the power of such systems as delivery devices has been established. Specifically, it is shown how it is possible to enhance the release kinetics of poorly soluble drugs by embedding them in mesoporous silicates. Further critical factors governing the structure and release of the model drug itraconazole incorporated in an SBA-15 matrix are briefly reviewed. The possibility of functionalizing the surface of mesoporous matrices also under harsher conditions offers a broad platform for the design of stimuli-responsive drug release, including pH responsive systems and systems which respond to the presence of specific ions, reducing agents, magnetic field or UV light, whose efficiency and biocompatibility has been established in vitro.


2018 ◽  
Vol 62 (3) ◽  
pp. 310-316 ◽  
Author(s):  
Balázs Farkas ◽  
Attila Balogh ◽  
Attila Farkas ◽  
András Domokos ◽  
Enikő Borbás ◽  
...  

Novel medicated straws were developed based on drug-loaded electrospun fibers prepared by direct current electrospinning (DCES) and high-speed electrospinning (HSES) of scaled-up productivity. Good quality micro- and nanofibers were electrospun using both techniques despite the multiple times higher throughput rate of HSES based on the scanning electron microscopic imaging (SEM). Solid state analyses revealed that the poorly soluble model drug carvedilol (CAR) was dispersed in an amorphous form in the electrospun polyvinylpyrrolidone (PVPK30) fibers. In vitro dissolution studies revealed ultrafast drug release from the prepared fibrous formulations inserted into plastic straws. Based on the results the developed drug delivery system is suitable for storing the formulation in a solid dosage form and in situ turning it into liquid form when administered.


2017 ◽  
Vol 69 (11) ◽  
pp. 1477-1484 ◽  
Author(s):  
Anna Justina Svagan ◽  
Anette Müllertz ◽  
Korbinian Löbmann

Author(s):  
MOHAMMAD F. BAYAN

Objective: The main aim of this study was to design a drug carrier capable to control and enhance the release of poorly water soluble drugs. Methods: Three polymeric formulations, based on poly (2-hydroxyethyl methacrylate) and loaded with different Capmul® MCM C8 concentrations (0, 10 and 20 % w/w), were prepared. Felodipine, which is a poorly soluble substance, was selected as a model drug. The effect of Capmul® MCM C8 on swelling behavior and in vitro release profile of the prepared polymer was investigated in PBS. Results: The swelling profiles of allformulationswere statistically similar, which indicated the non-significant effect of added Capmul® MCM C8 on polymer's swelling behavior. All formulations showed a delayed drug release. Formulation-F3, which is loaded with 20% w/wCapmul® MCM C8 displayed a significant higher release compared to the other formulations. Conclusion: Capmul® MCM products, which are widely used in food industries, can be used to improve the oral delivery of poorly soluble substances. The optimized formulation exhibited the ability to control and enhance the release of the model drug.


Author(s):  
Mashkura Ashrafi ◽  
Jakir Ahmed Chowdhury ◽  
Md Selim Reza

Capsules of different formulations were prepared by using a hydrophilic polymer, xanthan gum and a filler Ludipress. Metformin hydrochloride, which is an anti-diabetic agent, was used as a model drug here with the aim to formulate sustained release capsules. In the first 6 formulations, metformin hydrochloride and xanthan gum were used in different ratio. Later, Ludipress was added to the formulations in a percentage of 8% to 41%. The total procedure was carried out by physical mixing of the ingredients and filling in capsule shells of size ‘1’. As metformin hydrochloride is a highly water soluble drug, the dissolution test was done in 250 ml distilled water in a thermal shaker (Memmert) with a shaking speed of 50 rpm at 370C &plusmn 0.50C for 6 hours. After the dissolution, the data were treated with different kinetic models. The results found from the graphs and data show that the formulations follow the Higuchian release pattern as they showed correlation coefficients greater than 0.99 and the sustaining effect of the formulations was very high when the xanthan gum was used in a very high ratio with the drug. It was also investigated that the Ludipress extended the sustaining effect of the formulation to some extent. But after a certain period, Ludipress did not show any significant effect as the pores made by the xanthan gum network were already blocked. It is found here that when the metformin hydrochloride and the xanthan gum ratio was 1:1, showed a high percentage of drug release, i.e. 91.80% of drug was released after 6 hours. But With a xanthan gum and metformin hydrochloride ratio of 6:1, a very slow release of the drug was obtained. Only 66.68% of the drug was released after 6 hours. The percent loading in this case was 14%. Again, when Ludipress was used in high ratio, it was found to retard the release rate more prominently. Key words: Metformin Hydrochloride, Xanthan Gum, Controlled release capsule Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website


Author(s):  
Surender Verma ◽  
S. Singh ◽  
D. Mishra ◽  
Atul Gupta ◽  
Rakesh Sharma

The objective of present study was to develop colon targeted drug delivery using bacterially triggered approach through oral route. Valdecoxib (COX-2 inhibitor) was chosen as a model drug in order to target it to colon which may prove useful in inflammatory bowel disease and related disorders. Matrix tablets of Valdecoxib were prepared by wet granulation technique utilizing different ratio of Guar gum and Sodium starch glycholate. The prepared matrix tablets were evaluated for uniformity of weight, uniformity of content, hardness and in vitro dissolution study in simulated gastric and intestinal fluid (Phosphate Buffer pH-1.2, pH-6.8 and pH-7.4), followed by Dissolution study in bio-relevant dissolution media Phosphate Buffer (pH-6.8) containing rat caecal content. The results revealed that the formulated batch had released lesser quantity of drug at pH 1.2 and pH 7.4 in 2 hors whereas in biorelevent dissolution media containing rat caecal content it released significantly higher amount of drug which was also significantly higher than the dissolution media of same pH without caecal content (microflora) and it was concluded that guar gum can be used as a potential carrier for targeting drugs to colon.


2019 ◽  
Vol 16 (8) ◽  
pp. 688-697
Author(s):  
Ravinder Verma ◽  
Deepak Kaushik

: In vitro lipolysis has emerged as a powerful tool in the development of in vitro in vivo correlation for Lipid-based Drug Delivery System (LbDDS). In vitro lipolysis possesses the ability to mimic the assimilation of LbDDS in the human biological system. The digestion medium for in vitro lipolysis commonly contains an aqueous buffer media, bile salts, phospholipids and sodium chloride. The concentrations of these compounds are defined by the physiological conditions prevailing in the fasted or fed state. The pH of the medium is monitored by a pH-sensitive electrode connected to a computercontrolled pH-stat device capable of maintaining a predefined pH value via titration with sodium hydroxide. Copenhagen, Monash and Jerusalem are used as different models for in vitro lipolysis studies. The most common approach used in evaluating the kinetics of lipolysis of emulsion-based encapsulation systems is the pH-stat titration technique. This is widely used in both the nutritional and the pharmacological research fields as a rapid screening tool. Analytical tools for the assessment of in vitro lipolysis include HPLC, GC, HPTLC, SEM, Cryo TEM, Electron paramagnetic resonance spectroscopy, Raman spectroscopy and Nanoparticle Tracking Analysis (NTA) for the characterization of the lipids and colloidal phases after digestion of lipids. Various researches have been carried out for the establishment of IVIVC by using in vitro lipolysis models. The current publication also presents an updated review of various researches in the field of in vitro lipolysis.


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