Methods and Characteristics of Drug Extraction from Ion-Exchange-Resin-Mediated Preparations: Influences, Thermodynamics, and Kinetics.

Since the discovery of ion-exchange resins, they have been used in many fields, including pharmacy. Ion-exchange resin-mediated preparations can realize a series of functions, such as taste masking and regulating release. However, it is very difficult to extract the drug completely from the drug-resin complex because of the specific combination of the drug and resin. In this study, methylphenidate hydrochloride extended-release chewable tablets compounded by methylphenidate hydrochloride and ion-exchange resin were selected for a drug extraction study. The efficiency of drug extraction by dissociating with the addition of counterions was found to be higher than other physical extraction methods. Then, the factors affecting the dissociation process were studied to completely extract the drug from the methylphenidate hydrochloride extended-release chewable tablets. Furthermore, the thermodynamic and kinetic study of the dissociation process showed that the dissociation process obeys the second-order kinetic process, and it is nonspontaneous, entropy-decreasing, and endothermic. Meanwhile, the reaction rate was confirmed by the Boyd model, and the film diffusion and matrix diffusion were both shown to be rate-limiting steps. In conclusion, this study aims to provide technological and theoretical support for establishing a quality assessment and control system of ion-exchange resin-mediated preparations, promoting the applications of ion-exchange resins in the field of drug preparation.

Does methylphenidate treatment affect functional and structural ocular parameters in patients with attention deficit hyperactivity disorder? - A prospective, one year follow-up study.

Purpose: Methylphenidate hydrochloride, which blocks the reuptake mechanisms of dopamine and norepinephrine, is used in attention deficit hyperactivity disorder (ADHD) treatment. Methylphenidate has many general side effects including ocular findings. In this study, we investigated the long-term effects of methylphenidate treatment on functional and structural ocular parameters. Methods: In this prospective study, children with ADHD were evaluated. All patients underwent a detailed ophthalmic examination before methylphenidate treatment. All patients were examined in the 3rd, 6th, 9th, 12th months of methylphenidate treatment. Visual acuities, color vision, pupil diameters, static, dynamic and cycloplegic retinoscopy, intraocular pressure (IOP), anterior chamber depth (ACD), axial length (AL) were evaluated and recorded. Results: A total of 22 children were included in this study. The best-corrected visual acuities (BCVA) of all patients for both eyes were 0.0 logMAR, and 90.9% of patients had blue-purple color weakness before the treatment. After 1 year of treatment, none of the patients had any change in BCVA and color vision. However, an increase in myopic values of static retinoscopy and a decrease in hyperopic values of cycloplegic retinoscopy were found. Additionally, accommodation capacities were found to be decreased and AL was found to be increased significantly for both eyes. Pupil diameter, IOP, and ACD values did not change significantly. Conclusion: Our results suggest that patients with ADHD may have blue color vision deficiencies because of the decreased retinal dopamine levels. Additionally, structural and ocular parameters, especially accommodation capacity, may be affected by methylphenidate treatment.

A Case Report on a Young Male Taking Methylphenidate With Fasciculations and Dysphagia: Correlation or Causation?

Concurrent fasciculations and oropharyngeal dysphagia (OD) can be presenting signs of motor neuron disease (MND); however, there are other causes for OD (neoplasms, surgery, and gastroesophageal diseases, among others). Fasciculations (anxiety, benign, or iatrogenic) are an uncommon side effect (<1%) of methylphenidate. A 30-year-old male noticed fasciculations in both gastrocnemii, reporting gradual cranial progression, culminating in diffuse fasciculations with facial involvement. One month later, he reported OD for solids and occasional cough for liquids. He denied weakness, fatigue, or weight loss. He has no relevant personal history, apart from attention deficit hyperactivity disorder diagnosed a year before and since then medicated with methylphenidate 40 mg id. He had no abnormal findings on neurological examination. Electromyography (EMG) and sinus CT were normal. Upper gastrointestinal (GI) endoscopy (EGD) showed reflux esophagitis grade C, which could explain OD, and he started esomeprazole 40 mg id. As there were no findings on EMG, an iatrogenic etiology for fasciculations was considered. He suspended methylphenidate for a month and, two months later, reported a substantial improvement in fasciculations and resolution of the OD with the introduction of esomeprazole. Two simultaneous symptoms do not mean they are related. In this specific case, OD was the first symptom of gastroesophageal reflux disease (GERD), and fasciculations happened as a side effect of methylphenidate. This must be taken into consideration, as it can represent a confounding factor making the differential diagnosis more difficult. To the best of our knowledge, there are no published articles similar to this case report.

Effect of methylphenidate hydrochloride combined with mentalization-based family therapy on clinical efficacy and social function in children with attention deficit hyperactivity disorder / 中华行为医学与脑科学杂志

Objective:To observe the effect of methylphenidate hydrochloride (MPH) combined with mentalization-based family therapy (MBFT) on clinical efficacy and social function in children with attention deficit hyperactivity disorder (ADHD).Methods:Sixty-four children with ADHD diagnosed in Wuxi Children's Hospital and Affiliated Hospital of Jiangnan University from June 2019 to May 2021 were selected and divided into observation group ( n=32) and control group ( n=32) according to the random number table.Children in both groups received methylphenidate hydrochloride extended-release tablets, while those in the observation group were given additional MBFT.The duration of treatment was 12 weeks in both groups.The parent symptom questionnaire (PSQ), swanson nolan and pelham-version Ⅳ (SNAP-Ⅳ) parent Al scale, and Weiss impairment functional scale (WFIRS-P) were used to evaluate the effectiveness of treatment.Statistical analysis was performed by SPSS 25.0 statistical software.In particular, the χ2 test was used for counting data and the paired sample t test was used for comparison of measurement data between the two groups before and after treatment. Results:(1) All the PSQ dimension scores of patients in the observation group and the control group after treatment were significantly lower than those before treatment (all P<0.01). Compared with the control group after treatment, the PSQ dimension scores of personality and behavior problems ((1.25±0.15), (0.94±0.18), t=7.484, P<0.001), learning problems ((1.57±0.16), (1.32±0.20), t=5.522, P<0.001), psychosomatic disorders ((0.56±0.11), (0.44±0.13), t=3.986, P<0.001), impulse hyperactivity ((1.76±0.23), (1.54±0.25), t=3.663, P<0.001), anxiety ((0.94±0.12), (0.76±0.11), t=6.255, P<0.001) and hyperactivity index ((1.74±0.19), (1.51±0.16), t=5.238, P<0.001) decreased significantly in the observation group after treatment.(2) Compared with the pre-treatment period, the SNAP-Ⅳ scale scores of attention deficit, impulsivity-hyperactivity and oppositional defiance were significantly lower in both groups after treatment (all P<0.01); and compared with the control group, the SNAP-Ⅳ scale scores of the above three dimensions were significantly lower in the observation group (all P<0.01). (3) All six dimensions (family, learning and school, life skills, self-management, social activities, and risk-taking activities)of the WFIRS-P scale were significantly lower in the children in the observation group after treatment compared with those before treatment (all P<0.01), and all the six dimensions of the WFIRS-P scale were significantly lower in the observation group compared with those in the control group (all P<0.01). Conclusion:Methylphenidate hydrochloride extended-release tablets combined with MBFT can significantly improve the clinical symptoms and social function of children with ADHD.

Study on the Complexation and Release Mechanism of Methylphenidate Hydrochloride Ion Exchange Resin Complex.

Since the advent of ion exchange resin, it has been widely used in many fields, including drug delivery systems. The drug binds to the resin through an exchange reaction to form a drug-resin complex, which can gradually release drugs through the exchange of physiological ions in the gastrointestinal tract, to realize functions such as taste masking and regulating release. In this study, the complexes of methylphenidate hydrochloride and Amberlite IRP69 were prepared and evaluated to explore the mechanism of complexation, influencing factors and release mechanism at a molecular level. Firstly, with the properties of the selected complexes, molecular dynamics simulation was innovatively used to find that the intermolecular interaction between drug molecules and ion exchange resin molecules is mainly caused by the stacking effect of π and salt bridges. Secondly, with the drug loading status as an indicator, the factors affecting the compounding process of the drug and resin were explored. Finally, the release mechanism of the drug-resin complex was studied by mathematical model fitting. In summary, a variety of methods were used to study the mechanism of complexation and release between drug and resin, providing a theoretical basis for promoting the marketing of ion-exchange resin-mediated oral preparations.

Persistent Raynaud's Phenomenon Following Methylphenidate Hydrochloride Use During the COVID-19 Pandemic.

Raynaud's phenomenon (RP) is a medical condition characterized by vasospasm of the digital vessels in the fingers and toes. The prevalence of RP in the general population is estimated at 3-5% and can vary based on climate. It is classified into primary and secondary RP based on causality. RP has been reported in some cases diagnosed with coronavirus disease 2019 (COVID-19) infection. We report the case of a 14-year-old Caucasian female who presented during the pandemic with chief complaints of suicidal ideations and attempted suicide and had a history of attention-deficit hyperactivity disorder (ADHD) and persistent RP after a stimulant trial. After an initial failure of treatment with lisdexamfetamine, she was switched to methylphenidate hydrochloride (MPH). Within two months of starting MPH, the patient noticed skin discoloration of the lower legs and feet along with numbness. The discoloration of skin was mainly limited to her feet and gradually moved up her legs. She was advised to discontinue the MPH, but her symptoms persisted for four more months until her admission. Other etiologies were ruled out by multi-specialties and during her hospitalization. She was started on atomoxetine and buspirone with appropriate dose titration. Post-discharge from the hospital, no improvement was observed in the patient's RP at an outpatient follow-up performed within a month. The development of RP following MPH treatment and its persistence after stopping MPH is a fascinating event. Clinicians should be aware of the potential rare side effects of stimulants and stimulant-like medications, including vascular, hematological, and dermatological effects. Adolescents with ADHD may be particularly distressed by the COVID-19 pandemic and display increased behavioral issues. Stress can be a trigger for RP; therefore, minimizing stress in at-risk patients is essential.

The Efficacy of Acupuncture Treatment for Attention Deficit Hyperactivity Disorder: A Systematic Review and Meta-Analysis.

BACKGROUND: This study aimed to assess the efficacy of acupuncture for treating attention deficit hyperactivity disorder (ADHD) in children and adolescents. PATIENTS AND METHODS: Systematic review and meta-analysis including randomized controlled trials that compared the effects of acupuncture treatment (AT) with pharmacotherapy (methylphenidate hydrochloride, MPH) among patients with ADHD. A total of 12 electronic databases were searched from inception until February 3, 2020. The main outcomes were the effective rate and post-treatment hyperactivity scores. We also assessed the incidence of adverse events and follow-up course. RESULTS: A total of 10 studies involving 876 patients were included in this study. The meta-analysis revealed that AT yielded a significantly higher effective rate than MPH (odds ratio 2.239, 95% CI 1.438-3.487, p < 0.001, 8 studies), and that AT can reduce the hyperactivity scores to a lesser degree than MPH (standardized mean difference = -0.882, 95% CI -1.295 to -0.469, p < 0.001, 3 studies). Two studies reported no adverse events in the AT group, while one study suggested that AT can reduce adverse drug reactions. Furthermore, 3 studies concluded that the effects of AT were maintained, even after completion of treatment. CONCLUSION: This study suggests that AT may be more beneficial than MPH therapy for ADHD patients. However, the evidence may be highly limited, especially considering the outcome of hyperactivity scores with the high risk of bias, very low GRADE, and small number of studies. Thus, further studies of rigorous design and high quality are needed to confirm and strengthen the results, especially in the Western part of the world. Additionally, well-designed randomized controlled trials that evaluate adverse events and include a long-term follow-up should be conducted to determine the efficacy, safety, and side effects of AT for ADHD in children and adolescents.

Methylphenidate challenge test in adults with attention deficit/hyperactivity disorder (ADHD): Clinical effects and their predictors.

OBJECTIVE: Adult and children attention deficit/hyperactivity disorder (ADHD) share similar symptoms and responses to drugs such as methylphenidate (MPH). Yet, in Europe, these drugs remain unlicensed for adults. We aimed to assess the effects of an acute MPH challenge on the four dimensions concentration, impulsivity, tension, and general well-being in ADHD adults, and identify predictors of improvement. METHODS: Therapeutic Drug Monitoring was performed to measure MPH plasma levels. A Visual Analogue Scale was administered to patients before and after the acute MPH challenge to measure self-reported changes in the four dimensions. RESULTS: After the acute MPH challenge, our 71 patients showed significant improvement in concentration and tension. The MPH challenge dose correlated with lower patients' age, greater side effects, increased concentration (p = .008) and decreased tension (p = .001). At multiple linear regression MPH plasma levels and absence of postdose side effects predicted concentration improvement, MPH plasma levels predicted tension improvement. MPH plasma levels were significantly higher in patients who reported an improvement in concentration, tension, and impulsivity compared to nonimprovers (p's from .001 to .004). CONCLUSIONS: These findings point to the efficacy of MPH challenge in improving concentration and tension in adult ADHD, thus emphasizing the need for a broader treatment access for these patients.

Methylphenidate alters monoaminergic and metabolic pathways in the cerebellum of adolescent rats.

Abnormalities in the cerebellar circuitry have been suggested to contribute to some of the symptoms associated with attention deficit hyperactivity disorder (ADHD). The psychostimulant methylphenidate (MPH) is the major drug for treating this condition. Here, the effects of acute (2.0 mg/kg and 5.0 mg/kg) and chronic (2.0 mg/kg, twice daily for 15 days) MPH treatments were investigated in adolescent (35-40 days old) rats on monoaminergic and metabolic markers in the cerebellum. Data acquired indicates that acute MPH treatment (2.0 mg/kg) decreased cerebellar vesicular monoamine transporter (VMAT2) density, while chronic treatment caused an increase. In contrast, protein levels of tyrosine hydroxylase (TH) and the dopamine D1 receptor were not significantly altered by neither acute nor chronic MPH treatment. In addition, while chronic but not acute MPH treatment significantly enhanced dopamine turnover (DOPAC/dopamine) in the cerebellum, levels of dopamine and homovanillic acid (HVA) were not altered. Acute MPH (5.0 mg/kg) significantly modified levels of a range of cerebellar metabolites with similar trends also detected for the lower dose (2.0 mg/kg). In this regard, acute MPH tended to decrease cerebellar metabolites associated with energy consumption and excitatory neurotransmission including glutamate, glutamine, N-acetyl aspartate, and inosine. Conversely, levels of some metabolites associated with inhibitory neurotransmission, including GABA and glycine were reduced by acute (5.0 mg/kg) MPH, together with acetate, aspartate and hypoxanthine. In conclusion, this study demonstrated that MPH alters cerebellar biochemistry, and that this effect depends on both dose and duration of treatment. The therapeutic significance of these results requires further investigation.

Development and validation of an HPLC-UV method for analysis of methylphenidate hydrochloride and loxapine succinate in an activated carbon disposal system.

Unused medications have the possibility of being abused, causing serious harm to individuals who were not prescribed the drug. The Food and Drug Administration (FDA) recommends the proper disposal of unused prescribed medications to maintain safety and prevent environmental hazards. However, many of the current disposal techniques do not properly address safety. A drug disposal pouch containing granular activated carbon offers a unique disposal method to deactivate residual or expired medication in a convenient, effective, and safe manner. A robust and validated method for methylphenidate hydrochloride and loxapine succinate was developed using high-performance liquid chromatography (HPLC) and the deactivation efficiency of the disposal system was tested. Methylphenidate hydrochloride was analyzed on a C18 analytical column (250 mm × 4.60 mm, 100Å) using acetonitrile-water (0.05% (v/v) trifluoroacetic acid) as the mobile phase at a flow rate of 1.0 mL/min with a run time of 15 min and retention time of 7.8 min. Loxapine succinate was separated on a C8 100Å (250 mm × 4.6 mm, 5 µm) column maintained at 25 °C using a flow rate of 1.0 mL/min. The run time was 10 min and the retention time of the drug was around 4.6 min. Mobile phase was composed of acetonitrile and water (0.3% triethylamine) at pH 3.0 as 40:60 (v/v). Reference standard solutions (100 µg/mL) for both drugs were prepared by dissolving in mobile phases. These methods provide good linearity (R 2 = 0.999) over the range of 5-100 µg/mL for methylphenidate hydrochloride and 0.1-100 µg/mL for loxapine succinate. The assay methods were successfully applied to study the deactivation of these drugs.

Development and validation of an HPLC-UV method for analysis of methylphenidate hydrochloride and loxapine succinate in an activated carbon disposal system / 药物分析学报

Unused medications have the possibility of being abused, causing serious harm to individuals who were not prescribed the drug. The Food and Drug Administration (FDA) recommends the proper disposal of unused prescribed medications to maintain safety and prevent environmental hazards. However, many of the current disposal techniques do not properly address safety. A drug disposal pouch containing granular activated carbon offers a unique disposal method to deactivate residual or expiredmedication in a convenient, effective, and safe manner. A robust and validated method for methylphenidate hydrochloride and loxapine succinate was developed using high-performance liquid chromatography (HPLC) and the deactivation efficiency of the disposal system was tested. Methylphenidate hydrochloride was analyzed on a C18 analytical column (250mm × 4.60mm, 100?) using acetonitrile-water (0.05％ (v/v) trifluoroacetic acid) as the mobile phase at a flow rate of 1.0mL/min with a run time of 15min and retention time of 7.8min. Loxapine succinate was separated on a C8100? (250 mm × 4.6 mm, 5 μm) column maintained at 25 °C using a flow rate of 1.0mL/min. The run time was 10min and the retention time of the drug was around 4.6min.Mobile phase was composed of acetonitrile and water (0.3％ triethylamine) at pH 3.0 as 40:60 (v/v). Reference standard solutions (100 μg/mL) for both drugs were prepared by dissolving in mobile phases. These methods provide good linearity (R2 = 0.999) over the range of 5–100 μg/mL for methylphenidate hydrochloride and 0.1–100 μg/mL for loxapine succinate. The assay methods were successfully applied to study the deactivation of these drugs.

Lens opacities in children using methylphenidate hydrochloride.

PURPOSE: To assess clinical findings of eye examination in children having attention deficit hyperactivity disorder (ADHD) administered with methylphenidate hydrochloride. METHODS: Fifty-seven consecutive patients diagnosed of ADHD and administered with oral methylphenidate hydrochloride treatment for at least one year were involved in this study (Group 1). Sixty healthy subjects (Group 2) having demographic features similar to group 1 were involved as a control group. All patients underwent detailed ophthalmological examination. RESULTS: One hundred and seventeen consecutive subjects with a mean age of 11.2 ± 2.4 years (7-18 years) were enrolled. Fifty-seven consecutive patient (32 males, 25 females) under oral methylphenidate hydrochloride treatment (Group 1) and 60 healthy control subjects (30 males, 30 females) (Group 2)) were recruited for this prospective study. The mean methylphenidate hydrochloride dosage was 0.9 ± 0.1 mg/kg/day and the mean duration of methylphenidate hydrochloride usage was for 2.73 ± 0.73 years (1-7 years). High intraocular pressure was not observed in any of the patients in our study. We detected lens opacities in five eyes of five patients in group 1 (p = 0.019). The patient with the highest degree of cataract formation had been using MPH for 84 months and this patient's cataract score was P4. CONCLUSION: Long-term use of methylphenidate may cause lens opacities. In particular, patients who have been using methylphenidate for more than two years should go for regular eye examination.

Influence of Methylphenidate Hydrochloride prolonged-release tablets on the cognitive processing of children with attention deficit hyperactivity disorder / 中华实用儿科临床杂志

Objective To explore the influence of Methylphenidate Hydrochloride prolonged-release tablets on the cognitive processing of children with attention deficit hyperactivity disorder (ADHD).Methods Thirty ADHD children and 30 healthy controls were enrolled in this study,and the ADHD subjects were treated with Methylphenidate Hydrochloride prolonged-release tablets for (28 ± 3) days.Pre-test and post-test by the Das-Naglieri:Cognitive Assessment System(DN:CAS) were done to evaluate the cognitive function of all individuals.The differences of cognitive processing in pre-treatment and post-treatment of ADHD group with healthy control group were compared.The difference between before and after treatment of ADHD was also compared.Results Compared with healthy control group,there were lower of planning score [(21.86 ± 4.61) scores vs.(29.33 ± 5.06) scores],attention score [(25.00 ± 4.57) scores vs.(29.83 ± 3.79) scores],and the total scores [(111.93 ± 13.95) scores vs.(127.26 ±15.53) scores] in ADHD group,and there were significant differences (t =-5.976,-4.455,-4.023,all P ＜0.05).The matching number,planned codes,planned connections,expressive attention,number detection and receptive attention scores were also lower in ADHD group,and there were significant differences (t =-4.787,-3.703,-4.991,-2.216,-2.488,-3.219,all P ＜ 0.05).Compared with healthy control group,there were lower of planning score with significant difference [(25.53 ± 4.98) scores vs.(29.33 ± 5.06) scores,t =-2.931,P ＜ 0.05] in ADHD group after treatment,matching number and planned codes were lower with significant difference (t =-2.654,-2.044,all P ＜ 0.05) in ADHD group after treatment.In ADHD group,the scores of planning [(25.53 ± 4.98)scores vs.(21.86 ± 4.61) scores],simultaneous processing [(36.10 ± 7.10) scores vs.(34.13 ± 6.04) scores],attention [(27.90 ± 5.69) scores vs.(25.00 ± 4.57) scores] and the total score [(121.50 ± 16.55) scores vs.(111.93 ± 13.95) scores] were significantly higher after treatment than that before treatment and there were significant differences (t =-5.679,-2.949,-3.869,-5.963,all P ＜ 0.05);matching number,planned codes,planned connections,nonverbal matrices,number detection,receptive attention and word series were significantly higher after treatment than that before treatment,and there were significant differences (t =-2.528,-3.209,-3.890,-2.276,-4.489,-2.208,-2.373,all P ＜ 0.05).Conclusion The Methylphenidate Hydrochloride prolonged-release tablets can improve the function of cognitive processing in children with ADHD,especially in attention.

Influence of Methylphenidate Hydrochloride prolonged-release tablets on the cognitive processing of children with attention deficit hyperactivity disorder / 中华实用儿科临床杂志

Objective To explore the influence of Methylphenidate Hydrochloride prolonged-release tablets on the cognitive processing of children with attention deficit hyperactivity disorder (ADHD).Methods Thirty ADHD children and 30 healthy controls were enrolled in this study,and the ADHD subjects were treated with Methylphenidate Hydrochloride prolonged-release tablets for (28 ± 3) days.Pre-test and post-test by the Das-Naglieri:Cognitive Assessment System(DN:CAS) were done to evaluate the cognitive function of all individuals.The differences of cognitive processing in pre-treatment and post-treatment of ADHD group with healthy control group were compared.The difference between before and after treatment of ADHD was also compared.Results Compared with healthy control group,there were lower of planning score [(21.86 ± 4.61) scores vs.(29.33 ± 5.06) scores],attention score [(25.00 ± 4.57) scores vs.(29.83 ± 3.79) scores],and the total scores [(111.93 ± 13.95) scores vs.(127.26 ±15.53) scores] in ADHD group,and there were significant differences (t =-5.976,-4.455,-4.023,all P ＜0.05).The matching number,planned codes,planned connections,expressive attention,number detection and receptive attention scores were also lower in ADHD group,and there were significant differences (t =-4.787,-3.703,-4.991,-2.216,-2.488,-3.219,all P ＜ 0.05).Compared with healthy control group,there were lower of planning score with significant difference [(25.53 ± 4.98) scores vs.(29.33 ± 5.06) scores,t =-2.931,P ＜ 0.05] in ADHD group after treatment,matching number and planned codes were lower with significant difference (t =-2.654,-2.044,all P ＜ 0.05) in ADHD group after treatment.In ADHD group,the scores of planning [(25.53 ± 4.98)scores vs.(21.86 ± 4.61) scores],simultaneous processing [(36.10 ± 7.10) scores vs.(34.13 ± 6.04) scores],attention [(27.90 ± 5.69) scores vs.(25.00 ± 4.57) scores] and the total score [(121.50 ± 16.55) scores vs.(111.93 ± 13.95) scores] were significantly higher after treatment than that before treatment and there were significant differences (t =-5.679,-2.949,-3.869,-5.963,all P ＜ 0.05);matching number,planned codes,planned connections,nonverbal matrices,number detection,receptive attention and word series were significantly higher after treatment than that before treatment,and there were significant differences (t =-2.528,-3.209,-3.890,-2.276,-4.489,-2.208,-2.373,all P ＜ 0.05).Conclusion The Methylphenidate Hydrochloride prolonged-release tablets can improve the function of cognitive processing in children with ADHD,especially in attention.

Study on Preparation of Methylphenidate Hydrochloride Bipolar Controlled Release Osmotic Pump Tablets / 中国药师

Objective: To study the preparation method and process optimization of methylphenidate hydrochloride biphasic controlled-release osmotic pump tablets.Methods: Based on the preparation technology of double-layer osmotic pump slow-release tablets and combined with the principle of biphasic drug release behavior, the two-release preparation with two different release phases was prepared.Through the single-factor investigation of the drug-containing layer and the booster layer, the amount of the auxiliary materials was determined.The optimum compression method and the optimum coating parameters were obtained by studying the process parameters of tabletting and coating.Results: The prepared methylphenidate biphasic controlled-release osmotic pump tablets had two different release phases.The methylphenidate hydrochloride controlled-release osmotic pump tablets produced by the optimal formulat were good in appearance and reproducibility of drug content.In vitro release curves showed that the drug was released rapidly in the intial 0-2 hour time interval and was in line with zero-order release in 2-10 hour with good reproducibility.Conclusion: The preparation method is scientific, simple and complete, and can be used for preparation of methylphenidate hydrochloride biphasic controlled-release osmotic pump tablets.

Determination of Related Substances in Methylphenidate Hydrochloride for Injection by HPLC / 中国药房

OBJECTIVE:To establish a method for the determination of related substances in Methylphenidate hydrochloride for injection. METHODS:HPLC method was adopted. The determination was performed on Waters symmetry C18 column with mo-bile phase consisted of methanol-0.01 mol/L potassium dihydrogen phosphate solution(60:40,V/V)at the flow rate of 1.0 mL/min. The detection wavelength was set at 210 nm,the column temperature was 35 ℃ and sample size was 10 μL. RESULTS:The linear range of impurity A and B were 0.02-3.0 μg/mL(r=0.9998). The limits of quantitation were 0.2,0.6 ng,and the limits of detec-tion were 0.06,0.2 ng,respectively. RSDs of precision,stability and reproducibility were all lower than 2.0%;recoveries were 98.2%-100.0%(RSD=0.56%,n=9),98.0%-100.3%(RSD=0.70%,n=9),respectively. CONCLUSIONS:The method is sim-ple,accurate and suitable for the determination of related substance in Methylphenidate hydrochloride for injection.

Establishment of Drug Release Determination Method for Methylphenidate Hydrochloride Bipolar Con-trolled Release Osmotic Pump Tablets / 中国药师

Objective:To establish the drug release determination conditions and method for methylphenidate hydrochloride bipolar controlled release osmotic pump tablets. Methods: The drug release of the tablets was determined by HPLC using a Diamonsil C18 (250 mm × 4. 6 mm, 5 μm) column with acetonitrile-KH2 PO4 (0. 02 mol·L-1 ,and pH was adjusted to 3. 0 by 1% H3 PO4 solution) (30∶ 70) as the mobile phase at a flow rate of 1 ml·min-1 , the column temperature was 35 ℃ and the injection volume was 20 μl. The effects of release medium, release apparatus and rotation speed on the release of methylphenidate hydrochloride bipolar controlled release osmotic pump tablets were studied as well. Results:The established drug release determination method had a good linear rela-tionship within the range of 1. 0-24. 0 μg·ml-1(r=0. 999 5), and the average recovery was 100. 5%(RSD=1. 58%, n = 6). Un-der the conditions of 900 ml pH 3. 0 phosphate buffer solution as the release medium and the rotation speed of 50 r·min-1 , the drug was quickly released in 0-2h, and then the release behavior was complied with a zero-level model in vitro in 2-10h with the release e-quation of Q=5. 505t+44. 221(r=0. 994 5). Conclusion:The method is simple, accurate and reliable, and suitable for the quality control of methylphenidate hydrochloride bipolar controlled release osmotic pump tablets.

Study of anti-fatigue effect of methylphenidate hydrochloride oral fast dissolving films and its mechanism / 药学实践杂志

Objective To study the anti-fatigue effect of methylphenidate hydrochloride oral fast dissolving films (MPH-OFDF) and its mechanism .Methods 60 mice were randomly divided into 6 groups as:normal control group (physiological sa-line) ,model group (physiological saline) ,Yiqiyangxue oral liquids positive group (7 .00 mg/kg) ,MPH-OFDF high-dose group (5 .20 mg/kg) ,MPH-OFDF middle-dose group (2 .60 mg/kg) and MPH-OFDF low-dose group (1 .30 mg/kg) .Besides the normal control group ,model group and positive group were orally administered ,the other groups are administered with the drug once daily sublingually daily for consecutive 15 days .The mice were put in the load-weighted swimming test 30 min after the last oral administration ,then the anti-fatigue effect was assessed based on recording exhausting swimming time and detec-ting the levels of serum lactale dehydrogenase (LDH) ,creatine kinase (CK) ,triglycerides (TG) in mice .Results Compared with control group ,the middle-dose and the high-dose MPH could prolong the exhausting swimming time (P<0 .05 ,P<0 .01) and decrease the activity of LDH and CK significantly (P<0 .05 ,P<0 .01);in addition the middle-dose MPH could decrease the content of TG (P<0 .05) .Conclusion The MPH had marked anti-fatigue effect that may be associated with reduced ser-um LDH ,CK and TG .

Management of attention-deficit hyperactivity disorder in adults: focus on methylphenidate hydrochloride.

Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in young adults and causes significant psychosocial impairment and economic burden to society. Because of the paucity of long-term evidence and lack of national guidelines for diagnosis and management of adult ADHD, most of the data are based on experience derived from management of childhood ADHD. This article reviews the current evidence for the diagnosis and management of adult ADHD with special emphasis on the role of methylphenidate hydrochloride preparations in its treatment. Methylphenidate hydrochloride, a stimulant that acts through the dopaminergic and adrenergic pathways, has shown more than 75% efficacy in controlling the symptoms of adult ADHD. Although concern for diversion of the drug exists, recent data have shown benefits in preventing substance use disorders in patients with adult ADHD.

Transdermal characteristics of methylphenidate hydrochloride / 第二军医大学学报

Objective:To investigatethe transdermal delivery characteristics of methylphenidate hydrochloride (MPH) in vitro. Methods: Characteristics of MPH crossing nude rats skin were studied with Franz diffusion cells. A high performance liquid chromatographic (HPLC) method was established to determine the concentration of MPH crossed the skin. The permeability coefficient (P), steady state flux (J) and lag time(LT) for MPH through the skin of nude rats treated with various enhancers were compared with those of control. Results: The permeability coefficient increased with the increase of MPH concentration. The penetration of MPH through nude rats skin was obviously enhanced by 8%Azone and 5%propylene glycol (P