高效液相色谱法测定小儿氨酚烷胺颗粒中对乙酰氨基酚的含量

建立了高效液相色谱法测定小儿氨酚烷胺颗粒中对乙酰氨基酚的方法。采用Eclipse XDB-C18色谱柱(4.6mm×150 mm,5μm),以甲醇—水(40：60)为流动相,流速为1.0 mL·min-1,检测波长为275 nm,进样量为20μL。结果表明,对乙酰氨基酚浓度在5.84～58.4μg·mL-1范围内与峰面...     

2-HEMA-g-Na-PCMS: A Novel Polymeric Matrix for the Controlled Release of Paracetamol

2-hydoxyethyl methacrylate (2-HEMA) was graft copolymerized with sodium salt of partially carboxymethylated starch (Na-PCMS). Thus prepared, graft copolymer (2-HEMA-g-Na-PCMS) was used as a polymeric matrix for preparing controlled-release tablets of paracetamol. Tablets of standard specification were prepared using the wet granulation method. Ingredients utilized for tablet preparation were 2-HEMA-g-Na-PCMS graft copolymer, paracetamol and excipients. Tablets were characterized for disintegration time (min), hardness, angle of repose and percent friability. It was found that tablets prepared by the compression of graft copolymer, excipients and drug in specified ratios resulted in an excellent controlled-release tendency of paracetamol.     

Electrochemical waste water treatment: Electrooxidation of acetaminophen

Oxidation of acetaminophen at boron-doped diamond (BDD) and at Ti/SnO₂ anodes in a plug-flow divided electrochemical reactor led to electrochemical combustion, whereas at Ti/IrO₂ benzoquinone was the exclusive product except at very long electrolysis times. The difference is explicable in terms of the different mechanisms of oxidation: direct oxidation at the anode for Ti/IrO₂ vs. indirect oxidation involving electrogenerated hydroxyl radicals at BDD and Ti/SnO₂. At BDD, at which the efficiency of degradation of acetaminophen was greatest, the rate of electrolysis at constant concentration was linearly dependent on the current, and at constant current linearly dependent on the concentration. Current efficiencies for mineralization up to 26% were achieved without optimization of the cell design.     

Preparation and evaluation of gel formulations for oral sustained delivery to dysphagic patients

Background: Oral sustained release gel formulations may provide a means of administering drugs to dysphagic and geriatric patients who have difficulties with handling and taking oral dosage forms. Aim: We have designed gel formulations for the oral administration of paracetamol with suitable rheological characteristics for ease of administration to patients with swallowing difficulties and sufficient integrity in the acidic environment of the stomach to achieve a sustained release of this drug. Method: Gels formed by gelatin, agar, gellan, pectin, and xyloglucan were assessed for suitable gel strength and in vitro and in vivo release characteristics. Results: Gellan (1.5%?w/v) and xyloglucan gels (1.5%?w/w) had acceptable gel strengths for ease of swallowing and retained their integrity in the rat stomach sufficiently well to sustain the release of paracetamol over a period of 6 hours. Comparison of 1.5%?xyloglucan gels with a commercially available preparation with identical paracetamol concentrations demonstrated improved sustained release properties of the xyloglucan gels. Conclusions: Gels formed by gellan and xyloglucan have suitable rheological and sustained release characteristics for potential use as vehicles for oral delivery of drugs to dysphagic patients.     

Evaluation of dibutyrylchitin as new excipient for sustained drug release

Dibutyrylchitin (DBC), a lipophilic chitin diester, has been synthesized from chitin and butyric anhydride with methanesulfonic acid as catalyst. Exhaustive esterification of free alcoholic groups of chitin was assessed by FT-IR and ¹H-NMR spectroscopy. High degree of alkyl substitution allowed DBC to acquire an almost completely lipophilic character. Tablets of paracetamol and metformin employing DBC as major excipient, in comparison with starch, microcrystalline cellulose, lactose and polyvinylpyrrolidone, were prepared and rates of drug release were checked by dissolution test assays. DBC released drug at a lower rate than that of the other tested materials. A comparison study of rate release of metformin from DBC tablets and from metformin-hydroxypropyl methylcellulose prolonged release oral formulation available on the market has been also curried out. Under the same conditions and in the presence of the same amount of loaded drug, DBC released 64% of metformin whereas hypromellose-based tablets released 87%.     

HPLC法测定小儿速效感冒灵含量

目的:应用高效液相色谱法测定小儿速效感冒灵中的对乙酰氨基酚的含量。方法:用 C_(18)柱,以甲醇—水(52:48)为流动相,检测波长为232nm。结果:平均回收率(n=5 n 为进样次数)为100.2%、RSD 为0.35%。结论:该方法简单。快速,重现性好。     

对乙酰氨基酚在n-丁基吡啶六氟磷酸盐修饰碳糊电极上的灵敏测定（英文）

将离子液体（n-丁基吡啶六氟磷酸盐,[BuPy][PF6]）与石墨粉混合,制备了离子液体修饰碳糊电极（CILE）.在0.1mol/L醋酸盐缓冲溶液中（pH 4.7）,采用循环伏安法（CV）、方波伏安法（SWV）及计时库仑分析法研究了对乙酰氨基酚的电化学行为.结果表明：CILE对对乙酰氨基酚的氧化还原具有明显的电催化作用;在0.1V/s扫速下,对乙酰氨基酚的氧化还原峰峰电位差（ΔEP）为88mV;扩散系数（D）为1.214×10-7 cm2/s.对乙酰氨基酚的氧化峰电流与其浓度在0.5～10.0μmol/L范围内呈线性关系（r=0.998 8）,检出限为0.01μmol/L（S/N=3）.该修饰电极成功用于片剂与尿样中对乙酰氨基酚含量的检测,且具有制作成本低、稳定性好、易于重复和制备等特点.     

偏最小二乘紫外分光光度法同时测定维C银翘片中的维生素C和扑热息痛

在紫外224~294 nm波长区间内取36个波长点,测定25组标准混合溶液的吸光值并建立校正集,结合残差平方和确定了主因子数,运用偏最小二乘法预报待测样品两组份的含量。结果表明,在模拟样品的测定中,维生素C和扑热息痛平均回收率分别为97.0%和99.2%;RSD分别为4.0%和0.24%;均方根误差分别为0.151 5和0.079 5;将此模型用于4个厂家实际样品的测定,维生素C和扑热息痛平均加标回收率分别为93.75%~99.3%,98.4%~103%。该方法具有不需分离样品、操作简便等优点,用于维C银翘片中两组份的测定,结果令人满意。     

Pd-La/C催化加氢酰化一步合成扑热息痛

以对硝基酚 (PNP)为原料 ,Pd -La/C催化加氢一步合成对乙酰氨基酚。最佳工艺条件为在应温度 1 4 0℃ ,反应压力0 .7MPa,反应时间 2h ,对乙酰氨基酚的收率达 97%。