Formulation Parameters Affecting the Preparation and Properties of Microencapsulated Ion-Exchange Resins Containing Theophylline

Nairn, J. Graham

doi:10.1002/jps.2600790802

Cited by 42 publications

(11 citation statements)

References 13 publications

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“…Different controlled release of theophylline systems were also studied [24][25][26][27][28][29] . A previous study of PDEA-based microgels [30] shows that they are soft and film forming in contrast to high T g microgels.…”

Section: Introductionmentioning

confidence: 99%

Polyurethane/Poly(2-(Diethyl Amino)Ethyl Methacrylate) blend for drug delivery applications

Echeverría¹,

Pardini²,

Debandi

et al. 2015

Polímeros

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SbstractA pH-sensitive blend of polyurethane (PU) and poly(2-(diethyl amino)ethyl methacrylate (PDEA) with good film-forming capacity was prepared from the corresponding aqueous dispersions. The polymer matrix was first characterized by using FTIR, DSC, water vapor transmission and water swelling capacity at different pHs. The drug release profile of films was evaluated using a vertical Franz Cell and theophylline as model drug. The water swelling degree increases from 54 to 180% when the pH of the medium is changed from 6 to 2, demonstrating the pH-responsive behavior of the film. The in-vitro release studies indicate that an anomalous transport mechanism governs the theophylline release.

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Section: Introductionmentioning

confidence: 99%

Polyurethane/Poly(2-(Diethyl Amino)Ethyl Methacrylate) blend for drug delivery applications

Echeverría¹,

Pardini²,

Debandi

et al. 2015

Polímeros

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“…The smaller the values, the closer the release behavior approached zero order. The ratio of the cumulative release at 16 h (Q 16 ) to that at 24 h (Q 24 ) showed the drug release during the latter period. Therefore, the three parameters were set as indices to optimize the formulations.…”

Section: Optimization Of Formulations Using the Spherical Symmetric Mmentioning

confidence: 99%

A Novel Osmotic Pump Tablet Using Core of Drug-resin Complexes for Time-controlled Delivery System

Wang

Chen

et al. 2008

YAKUGAKU ZASSHI

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A novel elementary osmotic pump tablet was developed. The system uses the core of drug-resin complexes (DRCs) loaded with propranolol hydrochloride (PNH) for time-controlled delivery. In traditional osmotic pump tablets (OPTs), the lag time was always minimized. However, in the DRCs osmotic pump tablet (DRCOPT), the lag time was increased to achieve the time-controlled delivery. The quantity of osmotic agent in the core and channeling agent in the coating solution as well as weight gain were conˆrmed to be essential for the release behavior. A spherical symmetric design was applied to the optimization of the DRCOPT. The optimal formulation mainly consisted of DRC 100 mg, polyethyleneoxide (N80) 182 mg, and NaCl 30 mg. The ratio of cellulose acetate (CA)/polyethylene glycol 4000 was 15：3 (w/w) in coating solution, and the weight gain was 8％. The release behavior of the optimal DRCOPT was evaluated in media with diŠerent pH, rotation speeds, and ionic strength. It was found to generate a 2-h lag time, to deliver PNH at a rate of zero order from 2 h to 14 h in the medium of NaCl 0.15 mol/l, and the cumulative release at 24 h was 94％. Drug relee was independent of pH and rotation speed, but was proportional to ionic strength. In summary, the lag time could be used in therapeutic regimens with the characteristics of chronotherapy because of the lag time and provides a new concept for the development of osmotic pumps.

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“…Moreover, IERs can prevent the diffusion of drug when suspended in a nonionic medium, because drug release will be only promoted by the presence of competing ions, such as occurs in the gastrointestinal tract upon oral administration. The drug release rate from drug resinate beads can be further controlled by coating the drug-resinate beads using a variety of microencapsulation or coating processes (Motycka & Nairn, 1979;Motycka et al, 1985;Moldenhauer & Nairn, 1990;Torres et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Preparation of Codeine-Resinate and Chlorpheniramine-Resinate Sustained-Release Suspension and its Pharmacokinetic Evaluation in Beagle Dogs

Huanxiang

Cheng

Pan

et al. 2007

Drug Development and Industrial Pharmacy

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Using ion exchange resins (IERs) as carriers, a dual-drug sustained release suspension containing codeine, and chlorpheniramine had been prepared to elevate drug safety, effectiveness and conformance. The codeine resinate and chlorpheniramine resinate beads were prepared by a batch process and then impregnated with Polyethylene glycol 4000 (PEG 4000), respectively. The PEG impregnated drug resinate beads were coated with ethylcellulose as the coating polymer and di-n-butyl-phthalate as plasticizer in ethanol and methylene chloride mixture by the Wurster process. The coated PEG impregnated drug resinate beads were dispersed in an aqueous suspending vehicle containing 0.5% w/w xanthan gum and 0.5% w/w of hydroxypropylmethylcellulose of nominal viscosity of 4000 cps, obtaining codeine resinate and chlorpheniramine resinate sustained-release suspension (CCSS). Codeine phosphate and chlorpheniramine maleate were respectively loaded onto AMBERLITE IRP 69, and PEG 4000 was used to impregnate drug resinate beads to maintain their geometry. Ethylcellulose with di-n-butyl-phthalate in ethanol and methylene chloride mixture for the coating of drug resinate beads was performed in Glatt fluidized bed coater, where the coating solution flow rate was 8-12 g/min, the inlet air temperature was 50-60 degrees C, the outlet air temperature was 32-38 degrees C, the atomizing air pressure was 2.0 bar and the fluidized air pressure was adjusted as required. Few significant agglomeration of circulating drug resinate beads was observed during the operation. The film weight gained 20% w/w and 15% w/w were suitable for the PEG impregnated codeine resinate and chlorpheniramine resinate beads, respectively. Residual solvent content increased with coating level, but inprocess drying could reduce residual solvent content. In the present study, the rates of drug release from both drug resinate beads were measured in 0.05 M and 0.5M KCl solutions. The increased ionic strength generally accelerated the release rate of both drugs. But the release of codeine from its resinate beads was much more rapid than chlorpheniramine released from its resinate beads in the same ionic strength release medium. The drug release specification of the CCSS, where release mediums were 0.05 M KCl solution for codeine and 0.5 M KCl solution for chlorpheniramine, was established to be in conformance with in vivo performance. Relative bioavailability and pharmacokinetics evaluation of the CCSS, using commercial immediate-release tablets as the reference preparation, were performed following a randomized two-way crossover design in beagle dogs. The drug concentrations in plasma were measured by a validated LC-MS/MS method to determine the pharmacokinetic parameters of CCSS. This LC-MS/MS method demonstrated high accuracy and precision for bioanalysis, and was proved quick and reliable for the pharmacokinetic studies. The results showed that the CCSS had the longer value of Tmax and the lower value of Cmax, which meant an obviously sustained release effect, and its relati...

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Formulation Parameters Affecting the Preparation and Properties of Microencapsulated Ion-Exchange Resins Containing Theophylline

Cited by 42 publications

References 13 publications

Polyurethane/Poly(2-(Diethyl Amino)Ethyl Methacrylate) blend for drug delivery applications

Polyurethane/Poly(2-(Diethyl Amino)Ethyl Methacrylate) blend for drug delivery applications

A Novel Osmotic Pump Tablet Using Core of Drug-resin Complexes for Time-controlled Delivery System

Preparation of Codeine-Resinate and Chlorpheniramine-Resinate Sustained-Release Suspension and its Pharmacokinetic Evaluation in Beagle Dogs

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