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At least 19 recordsLinked to original sources
PubMed2005

Selection of excipients for extended release formulations of glipizide through drug-excipient compatibility testing.

For the development of extended release formulations of glipizide, techniques of thermal and isothermal stress testing (IST) were used to assess the compatibility of glipizide with selected excipients. Initially, differential scanning calorimeter (DSC) was used to evaluate the compatibility. IR spectrum of drug-excipient mixture was also compared with that of pure drug and excipient. Compatibility of excipients defined in the prototype formula was tested using IST. Based on the DSC results alone, magnesium stearate, meglumine, TRIS buffer, and lactose, were found to exhibit interaction with glipizide. Stressed binary mixtures (stored at 50 degrees C for 3 weeks) of glipizide and meglumine showed yellow coloration indicating potential incompatibility. Based on the results of DSC, IR, and/or HPLC, excipients defined in the prototype formula were found to be compatible with glipizide. The optimized formulation developed using the compatible excipients were found to be stable after 3 months of accelerated stability studies (40 degrees C and 75% RH). Overall, compatibility of excipients with glipizide was successfully evaluated using the combination of thermal and IST methods and the formulations developed using the compatible excipients was found to be stable.

Calorimetry, Differential Scanning↗
PubMed1996

A new approach to the safety assessment of pharmaceutical excipients. The Safety Committee of the International Pharmaceutical Excipients Council.

This article presents a set of proposed guidelines for the safety assessment of new pharmaceutical excipients. These guidelines were developed by the Safety Committee of the International Pharmaceutical Excipients Council and represent a new, scientifically based approach to establishing conditions for the safe use of proposed pharmaceutical excipients utilizing various routes of human exposure. They are based upon the best currently available toxicological science and have taken the deliberations of the International Conference on Harmonization into consideration. These guidelines were developed because there are no regulatory agency guidelines currently available which specifically address the toxicological testing of a material intended for use as an excipient in pharmaceutical preparations. Only materials which have been previously permitted for use in a pharmaceutical preparation or which have been permitted for use in foods may be considered safe under current practices. If implemented, these guidelines should expedite the review of a proposed new excipient by regulatory agencies.

Chemistry, Pharmaceutical↗
PubMed1998

Surface acidity of solid pharmaceutical excipients III. Excipients for solid dosage forms.

The surface acidities of pharmaceutical excipients are detected by color changes of acid-base indicators on the substrate's surface. To quantify the indicator's transition interval on the surface of hydrophilic excipients, as an organic solvent methanol is introduced for the preparation of indicator-excipient mixtures. The influence of the particle size on the determination of the surface acidity is investigated and particle size did not influence the determination within the particle size range investigated. Surface acidities of common excipients used in preparation of solid dosage forms are presented.

Cellulose↗
PubMed1999

Pharmaceutical evaluation of multipurpose excipients for direct compressed tablet manufacture: comparisons of the capabilities of multipurpose excipients with those in general use.

Recently, a novel type of multipurpose excipient (MPE) with high binding characteristics and high fluidity has been developed. In this study, the capabilities of MPEs (Ludipress and Microcelac) were compared with those of excipients in general use. Also, the effects on powder and tableting characteristics of the physical properties and contents of active ingredients were examined in tablets prepared with these MPEs by the direct compression method. Multipurpose excipients mixed with adjuvants such as fillers, binders, lubricants, disintegrants, and the like show superior fluidity and compressibility. Tablets containing very small amounts of highly active ingredients with little dispersion were prepared. However, with increases in active ingredient content, each of the physical properties was affected strongly by the properties of the active ingredient. Tablets with appropriate hardness and disintegration characteristics could be prepared by mixing of different types of MPEs.

Chemistry, Pharmaceutical↗
PubMedDate not supplied

Comparative study of flow parameters of excipients for direct compression excipients determined using a ring shear.

In a previous research it has been attempted to define the selective criteria for excipients used in direct compression by measuring their flow rate and their flow regularity. The control of flowability of Avicel PH 101 and Cellutab has now been realized using a ring shear cell. A comparison of results obtained shows a different behavior in both excipients. In this way, we obtained higher values of cohesion and friction coefficients for Avicel PH 101 than for Cellutab, and values of flow factor that indicate good flow for Avicel PH 101 and excellent flow for Cellutab.

Chemistry, Pharmaceutical↗
PubMed2001

Excipient-excipient interaction in the design of sustained-release theophylline tablets: in vitro and in vivo evaluation.

Sustained-release (SR) theophylline (TPH) tablets were prepared by applying the moisture-activated dry granulation method. The interaction between the excipients sodium alginate (SAL) and calcium gluconate (CG) was the base for the formation of a cross-linked matrix that may regulate TPH release from the formulated tablets. The prepared granules showed good physical characteristics concerning the flow properties and compressibility, with the angles of repose in the range 29-31, and the compressibility indices ranged between 15% and 25%. The granules had low friability values (3.0%-4.2%), depending on SAL:CG ratios. The corresponding tablets showed good physical properties, with a lower rate of drug release compared with the commercial TPH tablets (Quibron). The release of TPH from the prepared tablets was not markedly affected by either the concentration of added dry binder (carbopol 934) or the tablet hardness, indicating that the rate-determining step in drug release was the diffusion through the produced calcium alginate matrix. Tablets formulated with equal ratios of CG and SAL that showed good physical properties and slow TPH release were chosen for bioavailability studies in beagle dogs, and results were compared with those for Quibron. The in vivo data showed a comparable plasma concentration profile for both tablet formulations, with prolonged appearance of drug in the plasma in detectable amounts for up to 24 h. The formulated tablets showed 104.65% bioavailability relative to that of the commercial tablets. The rate and extent of absorption of TPH showed no significant differences from that of the commercial tablets. Moreover, no significant differences were found in the pharmacokinetic parameters related to the rate and extent of TPH absorption from the prepared and commercial tablets.

Alginates↗
PubMedDate not supplied

Pharmaceutical excipients. Adverse effects associated with inactive ingredients in drug products (Part I).

Excipient reactions have resulted from the use of clearly toxic substances (e.g. diethyleneglycol), the use of certain excipients in a susceptible group (e.g. very low birthweight neonates, patients with large surface area burns, patients with a history of asthma or contact dermatitis), the alteration of an excipient mixture resulting in altered bioavailability (e.g. phenytoin), and the deliberate or inadvertent extradural administration of preserved medications intended for intravenous use. Inadvertent excipient overdose has also occurred when unusually large doses of a drug containing a preservative were used [chlorbutol in morphine, ethanol in glyceryl trinitrate (nitroglycerin)]. Most excipient problems are preventable with knowledge of the currently available formulation. Government drug regulatory agencies have largely prevented introduction of a new toxic excipient; however, the new use of previously approved (but not adequately studied) excipients continues to result in unfortunate tragedies (e.g. the E-ferol incident). Populations at risk should be monitored carefully. Very low birthweight infants (less than 100g) have a well-demonstrated intolerance to many excipients, particularly during the first 2 weeks of life. Research should be directed toward development of non-preserved medications and safer diluents for this population. Drugs and excipients which have previously been demonstrated to be safer in other populations (e.g. doxapram) should be meticulously studied in this age group before widespread use is recommended. Asthmatic patients comprise another population that are frequently sensitive to excipient toxicity. In some cases, as in sulphiting agents, which are ubiquitous in foods as well as in medications, total avoidance may not be possible and prophylactic therapy may be beneficial. Inactive ingredients are clearly not consistently inert in their biological activity and therefore should not be listed as such. A more useful and concise term is excipient. It is highly recommended that all pharmaceutical manufacturers list all their excipients and make this available to practitioners and drug information centres. Alternatively or additionally, the package insert should list these excipients in accordance with good manufacturing procedures. This disclosure will help to determine the relative frequency and magnitude of problems (bioequivalence, toxicity, etc.) that excipients may have in the population, as well as enabling susceptible patients to avoid inadvertent exposure.

Excipients↗
PubMed2000

Pharmaceutical excipient development: the need for preclinical guidance.

Pharmaceutical excipients have a vital role in drug formulations, a role that has tended to be neglected as evidenced by the lack of mechanisms to assess excipient safety outside a new drug application process. Currently, it is assumed that an excipient is "approved" when the new drug formulation, of which it is a constituent, receives regulatory acceptance. Existing regulations and guidelines indicate that new (novel) excipients should be treated as new chemical entities with full toxicological evaluation. No guidance is available for potentially useful materials (essentially new excipients) available from other industries, e.g., food additives or for established excipients with a new application, e.g., dose route change. However, despite this situation, drug companies are actively evaluating new materials or applying new uses to established excipients. Recently developed excipients (e.g., materials giving "sugar-free" status to medical preparations, the cyclodextrins, and the hydrofluoroalkane inhalation propellants) and excipients undergoing development (e.g., chitosan, various enteric coating substances, liposomes, polymers derived from glycolic and lactic acids, and vaccine adjuvants) are all discussed. In light of many other areas of drug development having recently benefited from new or updated regulatory guidance, specific guidance to assist companies in the development of their excipients is urgently needed. Also, an excipient testing strategy would be an excellent topic for inclusion for International Conference on Harmonisation (ICH) consideration. Such guidance/discussion would complement the current advances in pharmacopoeial standardization of excipient quality. As a consequence, it may be possible to have excipients reviewed by a committee of an international pharmacopoeia with the safety data assessed by elected experts and published.

Chemistry, Pharmaceutical↗
PubMed2001

Pulmonary peptide delivery: effect of taste-masking excipients on leuprolide suspension metered-dose inhalers.

The purpose of this study was to evaluate the effect of taste-masking excipients on in vitro and in vivo performance of a leuprolide metered-dose inhaler (MDI) suspension formulation. Taste-masking excipients (aspartame and menthol) were added to a leuprolide suspension MDI formulation. The leuprolide MDI formulation with the taste-masking excipients was characterized in terms of milling time, particle size distribution, dose delivery and uniformity, and drug absorption in dogs. The data were compared with a formula that did not contain taste-masking excipients. It was found that the longer milling time for the leuprolide suspension with the taste-masking excipients was required to obtain a similar particle size distribution compared with the formula without taste-masking excipients using a fluid energy mill. Although measurable differences in mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) were not observed between the two formulations, the percent of particles < or = 5 microns and the actuator retention for the formula with the taste-masking excipients were significantly different from the formula without taste-masking excipients using the Marple-Miller cascade impactor. Taste-masking excipients did not show a significant effect on valve delivery and through-can dose uniformity. However, the mean ex-actuator dose was 150.4 mg for the formula with the taste-masking excipients and 162.2 mg for the reference formula, respectively, indicating a significant difference. In tracheostomized dogs, both formulations showed comparable pharmacokinetic parameters including Cmax, Tmax, AUC0-12 and bioavailability (F%), indicating that the taste-masking excipients do not have an effect on lung absorption of leuprolide acetate. Therefore, inclusion of taste-masking excipients in the leuprolide MDI suspension formulation showed a significant impact on drug micronization, exactuator dose, and particle deposition pattern. Mechanistically, the unfavorable performance of leuprolide MDI in the presence of taste-masking excipients could be due to modification of the properties of the suspension itself and alteration of propellant evaporation following actuation.

Administration, Inhalation↗
PubMed2003

Medicines containing pharmaceutical excipients with known effects: a French review.

OBJECTIVE: The 13/01/01 French decree published an official list of brands and their generic drugs and identified 38 groups of excipients with known effects which are responsible for side effects and contraindication respectively. Our objective was to review all medicines marketed in France containing these excipients and to disseminate this information to French health care practitioners. METHOD: The side effects and contraindications regarding these excipients have been documented in the French drug database Thériaque (http://www.theriaque.org). They were documented for each medicine containing these excipients in addition to the data mentioned in the Summary of Product Characteristics (SPC). Results were obtained on 1 June 2001 by using computerised queries from the database. RESULTS: Within the 38 groups, 300 specific excipients and derivatives with known effects were identified. Among the 8900 medicines (100%), 5567 medicines (62.6%) contained one or more of these excipients; 2483 contained 1 excipient, 1819 contained 2 excipients and 1265 contained 3 or more excipients; 410 side effects or contra-indications--were described according to the route of administration and the threshold dose. They were linked to these 5567 medicines; 5818 excipients with a threshold dose were mentioned in the 'composition' sections of these 5567 medicines. Among these 5818 excipients, 3385 quantitative doses were documented in the SPCs or EPARs. CONCLUSION: This review shows the extent of most of the excipients contained in medicines marketed in France. The dissemination of these data offsets the lack of information in the SPCs.

Adverse Drug Reaction Reporting Systems↗
PubMed2006

Physical stability of crystal hydrates and their anhydrates in the presence of excipients.

There are few studies in the literature that deal with the effect of excipients on the kinetics of vapor phase induced hydrate-anhydrate phase transformations. The main purpose of this study was to probe the phase stability of hydrate-anhydrate systems in the presence of hygroscopic and nonhygroscopic excipients following exposure to either dehydrating or hydrating conditions. Physical mixtures and compacts of model hydrate formers (theophylline and carbamazepine) and excipients (mannitol, microcrystalline cellulose (MCC), polyvinylpyrrolidone (PVP) K12 and K90) were stored at 22 degrees C and varying relative humidities. Raman spectroscopy was used to monitor the kinetics of transformation between hydrate and anhydrate. In general, excipients were found either to have no effect or to promote dehydration. For hydrate formation, excipients could accelerate, retard, or have no influence on hydration kinetics. MCC was found to have only minimal effects on either the dehydration or hydration kinetics of model compounds, whereas mannitol enhanced dehydration but had little effect on hydration. Different PVP grades showed a variety effects: PVPK12 greatly enhanced the dehydration of both theophylline monohydrate (MT) and carbamazepine dihydrate (DC). PVPK90 also enhanced the dehydration of DC, but had a negligible effect on MT. For hydrate formation, PVPK12 was found to have a retarding effect on theophylline anhydrous (AT) transformation, but enhanced the conversion of carbamazepine anhydrous (AC) to DC, PVPK90 also retarded the hydration of AT, but had no effect on AC. Optical microscopy and X-ray powder diffraction studies suggested that PVP (in particular K12), when stored at high RH, was able to result in the partial dissolution of the active pharmaceutical ingredient and hence changed the hydration process from a solid state to a solution-mediated transformation. In summary, the effect of excipients on the kinetics of dehydration and hydration is complex and needs be rationalized in terms of several excipient properties including physical state, chemical composition, and the possibility of specific API-excipient interactions. It is concluded that a multitude of factors will dictate, and often complicate, the final effect of excipients on the phase transformation kinetics of hydrate formers.

Carbamazepine↗
PubMed1995

Thermally induced denaturation of lyophilized bovine somatotropin and lysozyme as impacted by moisture and excipients.

The endothermic thermal transitions (i.e., denaturation) of lyophilized recombinant bovine somatotropin (rbSt) and lysozyme as seen via differential scanning calorimetry were evaluated with respect to moisture and excipients. The denaturation temperature, Tm, of rbSt and lysozyme decreased with increasing moisture irrespective of the excipient. However, the magnitude of the decrease elicited by moisture was dependent on the type of excipient. Furthermore, the effect of the excipient was dependent on the moisture content; excipients decreased Tm in low moisture solids (i.e., < 5% moisture) and increased it in hydrated solids (i.e., > 15% moisture). In the dry state (< 1% moisture), the addition of 50% sucrose, sorbitol, or glycerol lowered the Tm of rbSt from 161 degrees C to 136, 120, and 83 degrees C, respectively, indicating a destabilizing mechanism. Likewise, the Tm of lysozyme decreased from 156 degrees C to 142, 128, and 97 degrees C due to the addition of sucrose, sorbitol, and glycerol, respectively. At higher moisture contents, the excipients promoted a higher transition temperature at a given moisture content than the pure protein systems, indicating a stabilizing mechanism. An increase in the enthalpy of unfolding for dehydrated lysozyme was noted with increasing levels of moisture and/or excipient, despite the observed decrease in Tm. The thermal stability, or Tm, of the dehydrated proteins appeared to be correlated to the glass transition temperature (Tg) of the excipient, which in turn should be related to the Tg of the system. The lower the Tg of the excipient, the greater was the degree of destabilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Quality and functionality of excipients.

The quality of medicines depends not only on the active principles and production processes, but also the performance of the excipients. The traditional concept of the excipient as any component other than the active substance has undergone a substantial evolution from an 'inert' and cheap vehicle to an essential constituent of the formulation. The rapid evolution of scientific, regulatory and economic factors, the introduction of delivery systems and the advance in biopharmaceutics have led to a new interest in the role and functionality of the excipients. More than one thousand raw materials are available from a multitude of sources and are used today in the pharmaceutical industry. Their chemical structures vary from small molecules to complex natural or synthetic polymeric mixtures. Excipients are now chosen to perform a variety of functions to guarantee the stability and bioavailability of the drug substance from the drug product and its manufacturability on a production scale. Beyond the dosage form necessities, excipients are required to perform important and specific technological functions, particularly in the case of solid dosage forms. As a consequence, their characterisation must go beyond the simple tests for identity, purity and strength as prescribed in general by the Pharmacopoeia monographs. With the exception of the Textbook of Pharmaceutical Excipients, not many reference sources describing the physical mechanical characteristics of the powders for a specific role are available. Full physical characterisation of solid materials is now made possible with the help of high resolution analytical techniques on the molecular, particulate and bulk levels. This systematic approach is necessary to guarantee the behaviour of the excipient during the formulation and production phases. Some examples have been chosen in this mini-review in an effort to highlight the emerging trends in the development of 'tailor-made' materials. Three main approaches are followed by the industry: physical or minor chemical manipulation of materials already known, combination of two or more marketed excipients in order to reduce unwanted defects and, finally, preparation of new chemical entities with huge investments for the toxicity studies. Excipient harmonisation, standardised functionality tests, preformulation data bases and expert systems will contribute to change the conventional trial-and-error formulation approach into a far more scientific and technological development.

Chemistry, Pharmaceutical↗
PubMed1999

Drug and excipient diffusion and solubility in acrylate adhesives measured by infrared-attenuated total reflectance (IR-ATR) spectroscopy.

Infrared-attenuated total reflectance (IR-ATR) was used to measure drug and excipient diffusion in acrylate pressure-sensitive adhesives. The first part describes diffusion of drug and excipient from one adhesive layer to another. The IR-ATR spectrometer is used to continuously monitor the rate at which drug and excipient diffuse into the 'receptor' adhesive layer. In this way, the ability of the drug and/or excipient to leave an adhesive can be determined without any influence of receptor fluids or skin membranes. Data is reported here for terpineol and testosterone diffusion in isooctyl acrylate (IOA) and IOA-acrylic acid (AA) adhesives. It is shown that the diffusion rate is much higher in IOA adhesive than in IOA-AA adhesive. The second part describes the use of IR-ATR to measure the solubility of liquids in adhesives. In this method, a liquid excipient is placed in direct contact with an adhesive layer containing no excipient. The IR-ATR spectrometer is used to continuously monitor the rate at which excipient diffuses into the 'receptor' adhesive layer. At equilibrium, the IR spectrum can be compared to both the pure adhesive spectrum and the pure excipient spectrum to determine the solubility of the excipient in the adhesive. Data are reported here for terpineol in an IOA adhesive and for several liquids in an IOA-vinyl acetate adhesive.

Acrylates↗