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@#In this study, different functional layer formulations and process parameters were used to prepare the levomilnacipran hydrochloride sustained-release capsules, the influence of functional layer formulation and process factors on dose dumping was studied by comparing their release curves in 40% ethanol; and the risk of dose dumping of the self-developed drug was evaluated by the similar factors of the release curve of the self-developed drug and the reference drug.The results showed that as the coating weight increased, the degree of dose dumping decreased; when the concentration of ethanol in the coating liquid solvent was less than 80%, the dose dumping increased; as the atomization pressure and maturation time increase, the dose dumping became more serious. In 0% ethanol (purified water), 5% ethanol, 20% ethanol and 40% ethanol media, the self-developed and reference preparations had the same degree of dose dumping within the specified time, and rotation speed had no significant effect on the release of metformin in vitro. In summary, formulation factors such as coating weight gain, ethanol concentration in the coating solution solvent, and process factors such as atomization pressure and curing time have a serious impact on the dose dumping of sustained-release capsules.Under the optimal functional layer formulation and process, special attention should be paid to the control of risk of self-developed dose dumping.
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OBJECTIVE: To study the preparation technology of tamsulosion hydrochloride sustained-release capsules and investigate the release degree in vitro. METHODS: The pellets containing tamsulosin hydrochloride were prepeared in the fluid-bed using bottom gush medicine. Then, it was coated with ethylcellulose aqueous dispersion (surelease), and in the following procedures, water-based acrylic resin enteric system (Acryl-EZE®) was used as coating material, hydroxypropylmethylcellulose E6 (HPMCE6) was considered as porous agent by fluid-bed. Based on the release degree in vitro, prescription influence factors were evaluated, as well as drug releases curve was compared, according to the single factor experiment. RESULTS: The preparation technology referred in our research was available to make tamsulosin hydrochloride sustained-release capsules, and drug release curve of self-made sustained-release capsules was similar to the commercial one. Additionally, the products reproducibility of intra-batch and inter-batch was excellent. CONCLUSION: The tamsulosin hydrochloride sustained-release capsules prepared in this study exhibited ideal sustained-release characteristics in vitro. The formulation is reasonable and feasible. It is suitable for industrial production.
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OBJECTIVE: To prepare indapamide sustained release capsules and investigate its release in vitro. METHODS: Blank pellets, hydrated magnesium silicate, hypromellose cellulose, triethyl citrate, Eudragit RL 100, Eudragit RS 100, Eudragit LS 55, etc, were used as materials to prepare indapamide sustained release capsules The content was determined by HPLC, and the effects of different solid weight gains of sustained release material on release of indapamide from capsules were evaluated by in vitro release test. RESULTS: The release in vitro of the sustained release pills met the requirements when the solid weight gain of the materials was 5.0% to 5.3%. CONCLUSION: The optimum preparation technique of indapamide sustained release capsules is established, which has guiding significance for the practical manufacture.
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To prepare and study the pharmacokinetics and release bioavailability in olunteers and concentrations in plasma in patients. METHODS: Ethylcellulose was used matrix in phase separation-coacervation for preparation of microencapsulation. The release experiments were performed in a rotating shaker. The isoniazid concentration in plasma was determined by spectrophotometrical method following a single oral dose of sustained-release cupsule and ordinary tablet respectively given to 10 volunteers in a open randomized cross-over test. MCP86 was used to process main pharmacokinetic parameters. RESULTS: The sustained-release of capsule and ordinary teblet in vitro, T50 was 1 h and 0.032 h respectively. The drug in sustained-release capsule was sustained release over 10 h. The main parameters in body: ordinary tablets: cmax=11.12 μgml-1, tmax=1.41 h, K=0.201 h-1; sustained release capsule: cmax=4.99 μgml-1, tmax=1.80 h, K=0.03 h-1. The concentration of blood at 36 h was (0±0)μgml-1 and 1.63 μgml-1 respectively. Except tmax, there was significant difference between the two fomulations (P＜0.01). The concentration of blood in patient at 1.5 h and 36 h. ordinary tablet and sustained-release capsule respectively were (8.24±2.60)μgml-1, (0±0)μgml-1and (3.69±0.86)μgml-1, (2.09±0.56)μgml-1. CONCLUSION: The sustained-release capsule will play an important part in prevention and treatment of tuberculosis as the result of its reasonable formulation and simple technology.
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AIM: To study the correlation between the release rate in vitro and the absorption in vivo of Shenshen sustained-release Capsule(SSRC phenylethanoid glycosides). METHODS: Release rate of SSRC in vitro was tested with D-800LS dissolution tester. 8 rats were randomly divided into two groups. One group was orally fed on SSRC. Plasma levels were determined by UV and the absorption fraction was calculated according to Wagner-Nelson's formula. RESULTS: The correlation coefficient between the release rate in vitro and the absorption fraction in vivo was 0.9654 . CONCLUSION: There is a significant correlation between release rate in vitro and absorption in vivo to SSRC.
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OBJECTIVE:To study the pharmacokinetics and the bioavailability of naftopidil sustained-release capsules. METHODS:Naftopidil capsule and sustained-release capsules were given to five healthy male dogs respectively in an open randomized cross-over test.Naftopidil concentrations in plasma were determined by HPLC method.The pharmacokinetics parameters and the relative bioavailability were measured and compared between naftopidil capsules and sustained-release capsules.RESULTS:A one-compartment open model with first-order absorption kinetics best fitted the concentration-time data.The T 1/2 ,AUC 0～∞ ,C max and T max of naftopidil capsule were3.2?1.1h,3728.1?573.1ng?h/ml,697.5?94.2ng/ml and1.2?0.59h,these pharmacokinetics parameters of sustained-release capsules were5.9?0.8h,5518.3?391.1ng?h/ml and468.6?61.3ng/ml and4.0?0.7h respectively.The relative bioavailability of naftopidil sustained-release capsules was149.8?14.4%when compared with naftopidil capsules.CONCLUSION:Naftopidil sustained-release capsules have satisfactory property in slow release of drug and much higher bioavailability than naftopidil capsules.
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OBJECTIVE:Aspirin sustained release capsules(A-SRC) were prepared The release rate and bioavailability of A-SRC were studies METHODS:To study release mechanism by determining dissolution rate and to study relative bioavailability of A-SRC by determining serum concentrations in rabbits RESULTS:The release profile of A-SRC fitted zero-order kinetics This sustained release preparation had good release stability and high bioavailability in comparison with commonly-used aspirin sustained release capsules CONCLUSION:A-SRC showed obviously sustained release effect The drug concentration in blood kept steady and lasted long after oral administration,therefore the times of administration could be decreased Because the light-excipients were used in A-SRC,which had floating properties and could make drug release slowly A-SRC could decrease the irritations to gastrointestinal tract and other side effects
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Objective: To establish a method for content determination of triptolide in the sustained-release capsule of Tripterygium Wilfordii by high performance liquid chromatography.Methods: High performance liquid chromatography was performed on C18 column.The chromatographic conditions were as follows: Acetonitrile-water(40:60) as mobile phase;flow rate being 1.0 ml/min and the detecting wavelength at 220nm.Results:Triptolide had good linear relation within the range from 0.047 to 0.350?g/ml(r=0.9995).The average recovery was 99.88%(RSD=0.58%,n=5).Conclusion: This method is convenient,accurate,reproducible,which can be used for content determinaton of triptolide.