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The study's goal was to develop chrono modulated pulsatile tablets of methylphenidate hydrochloride with an extended-release pattern in the morning and an immediate burst release in the afternoon for exaggerated symptoms of attention deficit hyperactivity disorder match the circadian rhythm of disease, where high levels of l-3, 4-dihydroxyphenylalanine (DOPA) are observed in the afternoon, necessitating higher drug concentrations. The core tablets were made with Kollidon CL-SF as a super disintegrant at 4% and 8% concentrations, with microcrystalline cellulose PH 102 (Pharma grade) and Ludipress as diluents.The core tablets were then compress coated with a slow-release component blend containing different grades of hydroxypropyl methylcellulose (HPMC) at various concentrations of HPMC E50, HPMC E15M, or HPMC E4M, as well as 4% Ethocel. Among all formulations, the F10 formulation containing HPMC E50 at 70% showed the best drug release, with 60% of the dose released slowly over 4 h, followed by an immediate burst of the remaining 40% at the 5th hour. The effect of different diluents on in vitro drug release kinetics and in vitro dissolution studies were performed for all formulations, and A1 formulation containing Cellactose-80 as a diluent showed the best results, with results matching the circadian variations in the disease condition.

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. [ABSTRACT FROM AUTHOR]

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.

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. [ABSTRACT FROM AUTHOR]

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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. [ABSTRACT FROM AUTHOR]

• Sustainable fluorescence derivatization approach for spectrofluorimetric determination of methylphenidate hydrochloride. • Successful application to pharmaceutical dosage form and spiked human plasma. • Greenness evaluation by analytical eco-scale and AGREE tools. Autistic children commonly experience symptoms that overlap with those of attention deficit hyperactivity disorder, such as inattention and hyperactivity. Methylphenidate hydrochloride is a brain stimulant drug used to treat the principal symptoms of attention deficit hyperactivity disorder in autistic individuals. A sustained spectrofluorimetric approach for quantifying methylphenidate hydrochloride in tablets and spiked plasma was developed in this study. At 75°C in a borate buffer pH 9, methylphenidate hydrochloride was derivatized by 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) into a fluorescent derivative detectable at 538 nm following excitation at 475 nm. The approach has been validated using ICH criteria, and it proved a sufficient linear response curve with the studied drug concentrations ranging from 2 to 100 ng/mL. The described approach was selectively used to quantify methylphenidate hydrochloride in tablets and plasma without the impact of the matrix components. In addition, the approach's sustainability was investigated and compared to the published work using two greenness assessment metrics termed analytical eco-scale and Analytical GREEnness (AGREE). The findings suggest that the recommended approach is sustainable compared to the published work. [ABSTRACT FROM AUTHOR]