Development of Modified Release Diltiazem HCl Tablets Using Composite Index to Identify Optimal Formulation

• Published in: Drug development and industrial pharmacy Vol. 29; no. 5; pp. 565 - 574
• Main Authors: Gohel, M. C., Patel, M. M., Amin, A. F.
• Format: Journal Article
• Language: English
• Published: Colchester Informa UK Ltd 01-01-2003; Taylor & Francis
• Subjects: Antianginal agents. Coronary vasodilator agents; Biological and medical sciences; Cardiovascular system; Composite index; Compressive Strength; Delayed-Action Preparations - chemistry; Diltiazem - chemistry; Drug Carriers - chemistry; Drug Compounding; Factorial design; Galactans - chemistry; Gels; General pharmacology; Kinetics; Mannans - chemistry; Medical sciences; Models, Chemical; Modified guar gum; Modified ispaghula husk powder; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Plant Gums; Powders; Psyllium - chemistry; Solubility; Tablets; Tartaric acid; Tartrates - chemistry; Time Factors; Pharmaceutical technology; Coronary vasodilator agent; Benzothiazepine derivatives; Direct compression; Antiarrhythmic agent; Diltiazem; Buffering capacity; Tartaric acid; Dissolution; In vitro; Guar gum; Dosage form; Active ingredient; Tablet; Factorial design; Release
• ISSN: 0363-9045; 1520-5762
• DOI: 10.1081/DDC-120018645

Abstract
This article reports the preparation of tartaric acid treated ispaghula husk powder for the development of modified release tablets of diltiazem HCl by adopting direct compression technique and a 32 full factorial design. The modified ispaghula husk powder showed superior swelling and gelling as compared to untreated powder. Addition of compaction augmenting agent such as dicalcium phosphate was found to be essential for obtaining tablets with adequate crushing strength. In order to improve the crushing strength of diltiazem HCl tablets, to modulate drug release pattern, and to obtain similarity of dissolution profiles in distilled water and simulated gastric fluid (pH 1.2), modified guar gum was used along with modified ispaghula husk powder and tartaric acid. A novel composite index, which considers a positive or a negative deviation from an ideal value, was calculated considering percentage drug release in 60, 300, and 540 min as dependent variables for the selection of a most appropriate batch. Polynomial equation and contour plots are presented. The concept of similarity factor (f2) was used to prove similarity of dissolution in water and simulated gastric fluid (pH 1.2).