J. F. Bavitz

Some Effects of Relatively Low Levels of Eight Tablet Disintegrants on a Direct Compression System

AbstractEight common tablet disintegrants (Amberlite IRP-88, Corn Starch U.S.P. CLD, Explotab, Ac-Di-Sol, Sta-RX 1500 Starch, Polyplasdone XL, and Guar Gum) were used in concentrations of 0, 0.25, 0.5, 1 and 2% (w/w) in a direct compression system of 75:25 Unmilled Calcium Phosphate Dihydrate/Anhydrous Lactose. Using a Recording Powder Flowmeter (RPF) it was noticed that linearity of flow was relatively unaffected while g/sec. flow rate decreased with increasing concentrations. Each system was then lubricated and tableted keeping the applied pressure relatively constant. Evaluation of the resulting tablets showed that even at very low disintegrant concentrations, significant reduction in disintegration time took place. At the same time, very few detrimental effects often seen with tablet disintegrants, were noticed.

Effect of Moisture on the Physical and Chemical Stability of Granulations and Tablets of the Angiotensin Converting Enzyme Inhibitor, Enalapril Maleate

AbstractGranulations and tablets of enalapril maleate in a lactose matrix were stored in open petri dishes at a range of relative humidities and respective moisture uptakes measured, Extrapolation of the moisture uptake rates measured at the exaggerated humidities yielded a critical humidity, i.e. humidity where the moisture uptake rate is zero and, therefore, least detrimental to the product.Enalapril maleate was reasonably stable at the storage conditions. The hardness of the tablets decreased at all humidities except when stored with silica-gel. The disintegration times were unaffected except at very high humidities. The dissolution profiles of the tablets remained unchanged.

Hydrate Related Dissolution Characteristics of Norfloxacin

AbstractThe effect of moisture and temperature on the physical and chemical stability of solid oral dosage forms of Norfloxacin was studied. The physical properties of the dosage form, i. e. breaking strength and disintegration time were not affected adversely. Dissolution characteristics of Norfloxacin tablets were found to be affected by humidity conditions. Tablets with poor dissolution characteristics were improved to satisfactory rates by exposure to 21–25°C/75% relative humidity. Exposure to lower humidities and higher temperatures adversely affected dissolution rates. Once favorable dissolution rates were attained, however, they remained unchanged in spite of dehydration of the tablets.

Key Variables in Dosage form Design

AbstractThe study described herein was undertaken to learn more about the relationships between tablet properties and formulation/process variables. Five independent variables were varied according to a central composite star design, and a number of properties have been evaluated. A discussion of various statistical procedures/issues have been examined for exploratory studies such as this one.

Granulation Surface Area as Basis for Magnesium Stearate Concentration in Tablet Formulations

AbstractTablets provide drug delivery in a convenient and uncomplicated manner. Despite this apparent simplicity, they must comply with a formidable number of physico-chemical compendial requirements defined by specifications and test methods. What these specifications indirectly control is that each dosage form or each lot of dosage form my vary but the variance is held within stated limits.This communication focuses on the weight variation of formulation ingredients that my be allowed in general and for magnesium stearate in particular and to define a relationship between the lubricant level and granulation surface area of a calcium phosphate matrix to obtain optimal tablet properties.

Formula Optimization for a multiple Potency System with Uniform Tablet Weight

AbstractThe study described herein was undertaken to develop formulations for a multiple potency system, in but a single optimization experiment. To achieve the objective, Sequential Prediction Analysis, a unique statistical procedure, where a computer is instructed to provide responses to predetermined levels of independent variables, was successfully utilized

Disintgrability Characteristics of three Selected Tablet Excipients

AbstractThree relatively new tablet excipients which included a water-insoluble, anionic, polymer derived from cellulose1 (D1), a carboxymethyl substituted starch2 (D2), and a complex of aminoacetic acid and sodium carbonate3 (D3) were compared with each other and against Starch USP (D4) as to their ability to effect the disintegration of compressed tablets.In this study, tablets were made by direct compaction from both a soluble and Insoluble matrix containing a pharmacologically active drug substance. The drug substances were either a water-soluble, weak acid (A1), a water-insoluble, weak acid (A2), a water-soluble salt derived from an insoluble, weak base (A3), and a water-insoluble, weak base (A4).In addition to the initial (I) measurement, the disintegration tines were measured after six (M) and fourteen months (F) of storage at 30°C.The experimental results were statistically analyzed. The averages as well as the variabilities (uniformity) associated with the performance of the disintegrants were co...

Studies on a Dibasic Calcium Phosphate - Mannitol Matrix Tablet Formulation – A Complementary Combination

AbstractA tablet formulation made up principally of a dibasic calcium phosphate-mannitol matrix showed small but noticeable decreases in tablet breaking strength (hardness) on temperature and humidity aging. An investigation directed toward pinpointing the causative agent(s) was initiated wherein various formulations were stressed at elevated temperature and humidity conditions in open petri dishes.Calcium phosphate dihydrate was found mainly responsible for the adverse effects induced by the storage conditions. By coupling it with a hydrophilic material like mannitol, however, physical stability is improved. Thus, the physical stability induced by mannitol is complemented by the ease of processability conferred by calcium phosphate.

A Study of the Compactibility Characteristics of a Direct Compression and A Wet Granulated Formulation of Norfloxacin

AbstractCompaction characteristics of norfloxacin tablets manufactured by both wet granulation and direct compression procedures were studied with the aid of an instrumented single punch tablet press interfaced with a digital computer. Under comparable tabletting conditions, the direct compression formulation required less compressional force than the wet granulated formulation to produce tablets of similar breaking strengths, which indicates superior compactibility. The directly compressed tablets were found to disintegrate faster and release their active component more rapidly during the critical early stages of dissolu-tion. Dissolution and disintegration of the directly compressed tablets generally were less affected by changes in breaking strengths than those compressed from granulated systems.

Study of the Relationship Between the Initial Rate of Moisture Sorption/Desorption of Norfloxacin Tablets to the Total Moisture and Temperature of Surrounding Environment

AbstractThe relationship between absolute moisture content of air (expressed as pounds of water per pound of dry air) at 25°C and 40°C to the initial rate of moisture sorption/desorption of NORFLOXACIN tablets was studied. At the temperatures and relative humidities in the study, linear relationships were observed.The initial rate of moisture sorption/desorption was found to be dependent upon both the moisture content as well as the temperature of the surrounding environment.