Effect on Dissolution from Halving Methylphenidate Extended-Release Tablets

OBJECTIVE: To determine the effect on in vitro dissolution from cutting methylphenidate extended-release tablets in half. DESIGN: Ritalin-SR (Ciba Pharmaceutical Co.) and generic methylphenidate extended-release (MD Pharmaceutical Inc.) tablets were dissolved in water according to the method prescribed by the US Pharmacopeia under two conditions: whole and halved. Samples were collected at 15, 30, and 45 minutes and at 1, 2, 3, 3.5, 4, 5, 6, and 7 hours. Methylphenidate content was determined by HPLC. RESULTS: Halving the tablets caused a statistically significant increase in cumulative dissolution as early as 15 minutes. The difference in cumulative dissolution reached its maximum for both Ritalin-SR and generic methylphenidate extended-release tablets at 2 hours. At this time point, the percent dissolution of the whole versus halved tablets was 57% versus 74% (Ritalin-SR), respectively, and 49% versus 67% (generic), respectively. The dissolution profiles of halved and whole extended-release methylphenidate tablets were parallel from this point through the 7-hour collection period. At 7 hours, however, there was no difference in the cumulative dissolution of halved versus whole tablets. CONCLUSIONS: While statistical differences during in vitro dissolution do exist and pharmacokinetic ramifications have not yet been determined, the absolute differences in dissolution between halved and whole tablets are not great. Halving methylphenidate extended-release tablets may be a clinically acceptable means of achieving a small increment/decrement in dose without converting to a regular-release tablet.

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Comparison of Dissolution between Regular-Release and Halves of Extended-Release Methylphenidate Tablets

Journal of Pharmacy Technology ◽

10.1177/875512259801400508 ◽

1998 ◽

Vol 14 (5) ◽

pp. 209-211 ◽

Cited By ~ 1

Author(s):

John Erramouspe ◽

Eric J Jarvi

Keyword(s):

Pharmaceutical Company ◽

Extended Release ◽

In Vitro Dissolution ◽

Sample Collection ◽

Significant Difference ◽

Dramatic Difference ◽

The Difference

Objective: To compare the in vitro dissolution of methylphenidate hydrochloride from regular-release tablets to halves of extended-release tablets. Design: Regular-release 10-mg methylphenidate tablets and halves of 20-mg extended-release tablets from two manufacturers (MD Pharmaceuticals, Inc., and Ciba Pharmaceutical Company) were dissolved according to the USP method specified for regular-release methylphenidate tablets. Samples were collected at 0.25, 0.5, 0.75, 1, 2, 3, 3.5, 4, 5, 6, and 7 hours. Methylphenidate concentration was determined by HPLC. Results: Regular-release methylphenidate tablets had statistically greater cumulative dissolution at all sample collection times of 2 hours or less compared with halves of extended-release tablets. The most dramatic difference occurred in the first 30 minutes, at which time the difference in cumulative dissolution was 63% (generic) and 55% (Ritalin). At 3 hours and thereafter, there was no significant difference in cumulative dissolution. Conclusions: Despite being cut in half, extended-release methylphenidate still does not dissolve as fast as regular-release tablets. Halving methylphenidate extended-release tablets may be a clinically acceptable means of achieving a prolonged-acting 10-mg dose.

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An In Vitro Dissolution Method for Testing Extended-Release Tablets Under Mechanical Compression and Sample Friction

Journal of Pharmaceutical Sciences ◽

10.1016/j.xphs.2021.10.036 ◽

2021 ◽

Author(s):

Zongming Gao ◽

Leo N.Y. Cao ◽

Xiaofei Liu ◽

Li Tian ◽

Jason D. Rodriguez

Keyword(s):

Extended Release ◽

In Vitro Dissolution ◽

Mechanical Compression ◽

Dissolution Method

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FORMULATION AND IN VITRO EVALUATION OF SALBUTAMOL SULPHATE AND THEOPHYLLINE EXTENDED-RELEASE TABLETS USING MODIFIED POLYMERS

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2018v10i8.27865 ◽

2018 ◽

Vol 10 (8) ◽

pp. 67

Author(s):

Naveen Goyal ◽

Anil Kumar

Keyword(s):

Ethyl Cellulose ◽

Extended Release ◽

Research Work ◽

Drug Dissolution ◽

In Vitro Dissolution ◽

Direct Compression ◽

Compression Method ◽

Salbutamol Sulphate ◽

Modified Polymers

Objective: The main objective of this research work was to design, prepare and evaluate extended release (ER) tablets of anti-asthmatic drugs (salbutamol sulphate and theophylline) by direct compression method using diverse ratios of hydroxypropyl methylcellulose (HPMC K100M) and ethyl cellulose (EC) along with some other excipients.Methods: Extended-release matrix tablets of salbutamol sulphate and theophylline were successfully fabricated by direct compression method and coded the formulations as F1 to F7 depending on the ratios of modified polymers. The core tablets composed of hydrophilic polymers of various ratios that allow the discharge of drugs at a controlled rate after coming in contact with the aqueous medium. The designed tablets were subjected to various assessment parameters i.e. friability test, hardness test, drug content consistency and In vitro dissolution tests.Results: Prepared formulations were subjected to various assessment parameters and the findings obtained were within the prescribed limit. To perform the in vitro drug dissolution tests of fabricated tablets, the calibration plots of pure drugs using various solvents i.e. 0.1N HCl, phosphate buffer (pH 6.8) and distilled water were plotted. Dosage forms F1-F7 containing ethyl cellulose and HPMC K100M in various concentration demonstrates the prolonged medications discharge for up to 8 h, among these formulations, F6 shows 95.32±0.24 % for salbutamol sulphate and 94.19±0.39 % for theophylline release at the end of 8 h. This finding reveals that a particular window of concentrations of ethylcellulose and HPMC K100M was capable of providing prolonged drugs discharge.Conclusion: The results obtained in this research work clearly showed a promising potential of extended-release tablets containing a specific ratio of HPMC K100M and ethylcellulose as a release rate controlling polymers for effective treatment of asthma and chronic obstructive pulmonary diseases (COPD).

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