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PubMed1989

Cancer chemotherapy administered by activated carbon particles and liposomes.

In cancer chemotherapy, a specific drug delivery system is expected since many anticancer drugs show toxicity against not only cancer cells but also against normal tissues. The dosage form comprising anticancer drugs adsorbed on activated carbon particles or encapsulated in liposomes is developed as a drug-delivery system which enhances the therapeutic efficacy and reduces the adverse effects. The dosage forms are versatile in size and electric charge, so that large amounts of the drugs are distributed to the "targeted" organs or tissues and lesser amounts are distributed to the whole body. The dosage forms are designed to release the drugs slowly for a long time at local sites. Through this process, practical use of the dosage forms as an anticancer drug carrier results in an enhancement of anticancer efficacy on the local lesion and a decrease of systemic toxicity.

Adjuvants, Immunologic↗
PubMed1998

Comparing the use of short-acting and long-acting calcium channel blockers in an HMO.

One of the questions surrounding the controversy over the risks of MI among hypertensives taking calcium channel blockers (CCBs) is the dosage form, and whether the short-acting form may be more likely than the long-acting to increase the risk of MI. This preliminary study compared HMO members receiving the two dosage forms by sociodemographic and clinical characteristics, and by utilization (hospital, office visits, emergency room, outside of HMO services) prior to and during CCB use. The sampling frame was members with one or more dispensings for a CCB 1990 through 1994. Incident users were those who received one or more CCB dispensings and no cardiovascular disease-related drugs the year prior to their first dispensing of a CCB. CCB users were those who had at least 90 days of continuous CCB use. Short-acting outnumbered long-acting users by eight to one. Few incident users of long-acting CCBs were found. Among incident users, diagnoses and comorbidities were similar. In general, short-acting users appeared to have less risk of exposure to heart-related medications, but similar risks of exposure to non-heart-related drugs and to utilization of the various services during the year prior to first use. The odds of being exposed to heart-related medications and non-heart related medications and use of services during periods of use of CCBs were similar in general, but where differences were observed, the odds of being exposed were less among short-acting users. Users of the two dosage forms in this setting prior to reports questioning the safety of short-acting CCBs were different quantitatively and qualitatively making a retrospective comparative study difficult, perhaps not possible, due to substantial selection bias among users. Further patient selection bias has also undoubtedly occurred subsequent to the reports. The final answer to the relative safety and effectiveness of the different dosage forms of calcium channel blockers is likely to have come from randomized clinical trials.

Journal Article↗
PubMed1980

A multiple-dose study of sustained-release theophylline and aminophylline.

This study evaluated the relative bioavailability of a sustained-release capsule of theophylline, an elixir of theophylline, and a sustained-release tablet of aminophylline. Twelve healthy, nonsmoking, adult male subjects received nine doses of each of the three products in a crossover study conducted over a ten-day period. Each dosage form contained approximately 250 mg of theophylline and was administered every eight hours. Concentrations of theophylline in the plasma at steady state demonstrated the equivalence of the three dosage forms in terms of the percent of drug absorbed, including the tablet which had exhibited reduced bioavailability in an earlier single-dose study of only five subjects. The steady-state average concentrations of theopylline in the plasma were 9.8 micrograms/ml, 10.3 micrograms/ml and 10.8 micrograms/ml for the tablet, capsulse, and elixir, respectively. The areas under the curves of the plasma level vs time for the three dosage forms were within 9 percent of each other. These data indicate that a significant reduction in fluctuations of the plasma level of theophylline was achieved with the two sustained-release dosage forms, compared to the elixir.

Adult↗
PubMed2003

[Characteristics of pharmaceuticals in "Heji Jufang"].

Dosage forms, methods of preparation, and methods of taking drugs for formulas described in "Heji Jufang" were investigated and the following results were obtained.1) Powders and pills (processed medicines), which are dosage forms seldom used in conventional traditional Chinese medicine, are often seen in "Heji Jufang". On the other hand, the fact that decoction (non-processed medicines), which is the principal dosage form in traditional Chinese medicine, seldom appears became apparent. In addition, a method of taking the drug by boiling down the powder was frequently seen.2) When decoction formulas are described in "Heji Jufang", the herbal medicines are often classified into two sections, a preceding section and latter one. The herbal medicines as prepared at a pharmacy are listed in the preceding section, while "standard household items" to add during home preparation are assumed to be described in the latter section.3) In "Heji Jufang", there is a rare method of taking drugs where boiling water is poured on powder consisting of aromatic herbal medicine before use. Many of these formulas are found in "Yinshan Zhengyao", which contains food and drink of the Arab region.4) "Heji Jufang" contains confections prepared with honey and powders of crude drugs. This dosage form is often seen in Indian and Arab medicine and was rarely seen in medical books before "Heji Jufang" in China.5) Thus, results 1-4 suggest that "Heji Jufang" was published in accordance with the development of processed medicines. It is believed that Arab medicine influenced the development of processed medicines in China.

History, 20th Century↗
PubMed1989

The influence of different formula diets and different pharmaceutical formulations on the systemic availability of paracetamol, gallbladder size, and plasma glucose.

The influence of two liquid formula diets on the systemic availability of paracetamol was investigated in 12 healthy normal volunteers using a liquid and a solid paracetamol dosage form. The diets contained the same balanced amounts, but different patterns of nutrients and different amounts of dietary fiber. Plasma glucose and gallbladder response to the standard meal were used as indicators of gastric emptying. Paracetamol plasma concentrations following application of the liquid dosage form also served as a marker for the gastroduodenal transport of liquid gastric contents. For the liquid dosage form, the plasma concentration time curves did not vary with diet composition. However, with the tablets, a differential effect was observed. Following coingestion with the fiber depleted diet, the rate of systemic availability was reduced more than with the liquid preparation. A further delay was obvious, when the tablets were combined with the meal enriched in dietary fiber. Plasma glucose and gallbladder response did not vary with diet composition. Variations of gastric emptying are unlikely to account for the variability of food effects. Consequently our results illustrate that an interaction of certain meal components with a particular drug dosage form determines the rate of intragastric release of the active compound. This could be shown due to a high standardization of nutrition by using liquid formula diets. Because of the variation of drug release, paracetamol cannot be used as a marker of gastric emptying without taking into account the vehicle necessary for drug application. In contrast to previous studies, our data provide evidence that even balanced test meals retard paracetamol absorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaminophen↗
PubMed2003

Evaluating dissolution profiles of an anti-HIV agent using ANOVA and non-linear regression models in JMP software.

A powerful statistical method was designed using JMP software to detect factors contributing to differences in the dissolution process of an antiviral drug delivered in an oral dosage form. Due to the large number of dissolution media available for solid dosage forms, a statistical method to choose the appropriate medium is critical for testing solid dosage forms. We have developed an analysis of variance model to analyze the overall dissolution profile obtained from the various media. In vitro tests were performed using a standard USP basket apparatus (Vankel Inc., Cary, NC), and the analysis used the restricted/residual maximum likelihood method (JMP software) to partition the variance due to media (pH 1.2 and 6.8, +SDS, water alone and at pH 1.2 with pepsin), time (repeated measure) and capsule (random effect). This allowed correct standard error estimates to be used to compare dissolution in different media using planned linear contrasts. The model provided us with statistically powerful criteria to identify significant differences in capsule dissolution across time and to quantify capsule-to-capsule population variance estimate. The time specific linear contrasts showed the largest sum of square values (SS) occurred at 180 min (SS=0.268) for the simulated SIF (pH 6.8) versus SGF (pH 1.2) comparison (DF=166, MSE=3.92 x 10(-3)). The dissolution processes were further characterized using a non-linear regression fit of a power law function to the data for each capsule. This resulted in a method to statistically differentiate between the dissolution processes of the capsules in different media.

Analysis of Variance↗
PubMed2004

Emerging techniques in the treatment of postoperative pain.

PURPOSE: Causes of inadequate postoperative pain control, challenges with currently available analgesic therapies, characteristics of optimal postoperative analgesic therapy, a liposome-encapsulated, sustained-release dosage form of morphine, and other investigational analgesic therapies are described. SUMMARY: Technical difficulties in analgesic drug administration, inappropriate prescribing, unfounded patient fears or expectations, and the lack of availability of parenteral dosage forms of certain analgesic agents can potentially contribute to inadequate postoperative pain control. The use of epidural catheters for analgesic therapy is limited by the use of prophylactic anticoagulation, the tendency for catheters to migrate and fail, and the need for nursing staff time to monitor the catheter site and infusion pump. Continuous peripheral blocks are not always effective, the devices used are bulky, and the technology is prone to failure. Multimodal therapies are labor-intensive, and some components must be given orally because they are not available in parenteral dosage forms. Optimal postoperative analgesic drug therapy would therefore be noninvasive, easy to administer, require no cumbersome equipment, cause no or minimal adverse effects, and be safe to use in patients receiving prophylactic anticoagulation. A new morphine sulfate sustained-release liposome injection has several of these characteristics, including ease of administration and compatibility with anticoagulation. Single-dose epidural administration of morphine sulfate sustained-release liposome injection in patients undergoing hip arthroplasty provided better pain control than i.v. opioid analgesics given by PCA, with similar adverse effects. CONCLUSION: Opioid analgesics remain the mainstay of postoperative analgesic therapy, but the development of infusion pumps with improved reliability; needle-free technologies, parenteral dosage forms of acetaminophen, selective cyclooxygenase-2 inhibitors, and other non-opioid therapies; and new opioid analgesic agents that provide analgesia without the adverse effects of currently available opioid analgesics may substantially improve postoperative analgesia and health-related quality of life in the postoperative pain patient in the future.

Analgesics↗
PubMed2003

[Immunotherapy with grouped doses].

Once the efficacy and safety of immunotherapy with allergen extracts has been shown, recently it has become evident the need for perfecting those aspects of the treatment that can be improved, such as its dosage form. The conventional dosage of subcutaneous immunotherapy in the phase of dose increase is slow in reaching an efficient level. For this reason other alternative dosages to the conventional one have been tried out, such as grouped dosages, which shorten this period of dose increase. On condition that the safety of the treatment is guaranteed, these doses offer the advantages of reducing the economic cost and the time involved, of reducing the discomfort of the treatment and of improving the patient's adherence to the treatment, and possibly of reaching clinical efficacy more rapidly. Nonetheless, it is not easy to determine the suitable dosage of administration (the shortest and with the least number of adverse reactions) and this article reviews the existing problems when it comes to designing these grouped doses. Finally, we present the results of a comparative study between the conventional dose and a grouped dose, with a double blind design, carried out by us, which shows that the grouped dose is quicker in achieving the desired clinical efficacy, shortens the times of reduction of cutaneous sensitivity to the allergen and of modification of the immunological parameters, all with a low frequency of adverse reactions that is similar to that registered with the conventional dosage.

Adolescent↗
PubMed2003

Application of artificial neural networks in the design of controlled release drug delivery systems.

Controlled release drug delivery systems offer great advantages over the conventional dosage forms. However, there are great challenges to efficiently develop controlled release drug delivery systems due to the complexity of these delivery systems. Traditional statistic response surface methodology (RSM) is one of the techniques that has been employed to develop and formulate controlled release dosage forms. However, there are some limitations to the RSM technique. Hence, another technique called artificial neural networks (ANN) has recently gained wide popularity in the development of controlled release dosage forms. In this review, the basic ANN structure, the development of the ANN model and an explanation of how to use ANN to design and develop controlled release drug delivery systems are discussed. In addition, the applications of ANN in the design and development of controlled release dosage forms are also summarized in this review.

Delayed-Action Preparations↗
PubMed2006

Assessing and monitoring override medications in automated dispensing devices.

BACKGROUND: Medication override is not without risk because the absence of pharmacist review may increase the potential for a medication error. The University of Pittsburgh Medical Center's Department of Pharmacy and Therapeutics assessed the safety of the automated dispensing device (ADD) override process to reduce the number of override medications stored in the ADD. METHODS: A representative expert panel developed criteria for override access and revised the override medication list; an override monitoring tool was used to perform random audits and determine nursing compliance; and changes in override practices for use of opioids, a high-alert medication class, were measured. RESULTS: The expert panel reduced the number of medications and dosage forms on the override list by 42%, from 119 different medications (in 244 different dosage forms) in 2001 to 92 different medications (in 163 different dosage forms) by December 2003. By May 2004 the opioid override rates were significantly decreased; although slight increases in rates occurred by December 2004, possibly reflecting the lack of formal override monitoring by nursing and pharmacy, the rates were still significantly lower than the baseline in October 2003. CONCLUSION: Pharmacists, in collaboration with the medical and nursing staffs, developed a sustainable process for preventing unauthorized and inappropriate override medication dispensing from ADDs.

Hospital Bed Capacity, 500 and over↗
PubMed2000

[Effect of macromolecular substances on pharmaceutical availability of a potential local anesthetic].

Within the framework of the study of the derivatives of phenylcarbamic acid with a local anaesthetic effect, one of them, a potential medicinal agent with the working name of XX B, chemically N-[2-(3-heptyloxyphenylcarbamoyloxy)-ethyl]-dimethylammoniumchl oride, was investigated. Linking up with the previous studies, the paper investigated the effects of two auxiliary substances--cellulose derivatives (hydroxyethylcellulose, methylcellulose)--and their concentration on the pharmaceutical availability of the potential drug XX B from the dosage form. At the same time the effect of the employed concentration of the macromolecular substances on the viscosity of the dosage form was examined. The study revealed that with the growing concentration of cellulose derivatives the viscosity of the prepared dosage forms was increased, and the release of the active ingredient was decelerated. Both auxiliary substances influenced the pharmaceutical availability of the potential drug XX B in an approximately identical manner, and thus both could be employed for the same purpose.

Anesthetics, Local↗
PubMed1980

Pharmacokinetics--one user's perspective.

Rate/duration-specified drug delivery systems have recently begun to appear as pharmaceuticals and as research tools. In both therapeutics and research, their major advantage is prevention of transient peaking of blood or tissue concentrations that are side-effect producing and potentially toxic; these peaks are the rule with conventional drench- or pulse-modes of drug administration via ordinary dosage forms. Each drug's pharmacokinetics provides the basis for specifying the rates at which its controlled delivery dosage forms should function in vivo. That is what pharmacokinetics can do for controlled drug delivery systems. What the availability of controlled drug delivery systems can do for pharmacokinetics is to make it both convenient and economical to study the steady-state pharmacokinetic behavior of a drug during chronic administration--as opposed to the much more complex and costly procedure of studying the transient pharmacokinetic behavior of the drug. Moreover, achieving and maintaining an approximately steady-state simplifies the study of spatial gradients in drug concentration in body fluids and tissues. In this fashion, advances in the technology of dosage forms, and the conversion from their static specification only by quantity to a dynamic specification by rate/duration, are strongly interdependent with both the theory and practice of pharmacokinetics.

Dosage Forms↗
PubMed1998

[The effect of different variables on the in vitro dissolution of a theophylline sustained-release preparation].

In vitro dissolution studies are valuable tools to judge quality and stability of sustained release dosage forms and are often utilised to predict the in vivo performance. For this reason, in vitro dissolution experiments with varying pH, osmolarity, rotation speed, and with addition of surfactants were performed with a sustained release theophylline (CAS 58-55-9) dosage form (Bronchoretard). In order to mimic the physiological situation of the gastrointestinal tract more closely, the pH of the dissolution media was changed and human bile was added at different time points. The results obtained show that the in vitro dissolution of the dosage form differs only slightly for the parameters pH, osmolarity and stirring speed and always lies within in vivo verified dissolution limits. However, the addition of sodium dodecyl sulphate to the dissolution medium markedly altered the dissolution rate whereas addition of the physiologically surface active human bile did not change the dissolution rate. A comparison with in vivo results indicated, that only the physiologically adapted model guarantees reliable results whereas the addition of synthetic surfactants cannot allow for the prediction of bile or food effects. The meaning of in vitro dissolution tests thus is limited to development studies of dosage forms and to routine quality and stability control testing. For judging the in vivo characteristics in vitro studies have only limited value and have to be verified by pharmacokinetic studies.

Anti-Asthmatic Agents↗
PubMed1994

Biopharmaceutical aspects of anti-infective therapy at the extremes of age.

Optimal anti-infective therapy at the extremes of age can be supported by the development of appropriate dosage forms. With regard to neonates, infants and children an oral liquid formulation appears to be superior compared with standard formulations such as tablets and capsules, since individualized dosing by body weight or body surface area is more easily achieved. Reformulation of marketed dosage forms, such as crunched tablets or opened capsules, by the hospital pharmacist may result in stability and bioavailability problems and therapeutic failures may be the consequence. With regard to the elderly a reduction in dosing frequency and individualized dosing are important in order to increase compliance. A reduction of dosing frequency can be achieved by oral controlled-release dosage forms, which are designed to release the drug in small amounts at predefined rates. However, to permit ease of swallowing they require a relative small daily dose together with excipients. In addition absorption must occur throughout the entire gastrointestinal tract; this is not the case for several antibiotics. Various advantages and disadvantages of oral liquid and oral controlled-release dosage forms are discussed. In the development of an oral formulation, in addition to a standard tablet a variety of information, such as physico-chemical characteristics, pharmacokinetics and pharmacodynamics must be available. Physico-chemical disadvantages can largely be solved by advanced pharmaceutical concepts, such as the pro-drug approach, complex formation or coprecipitation, which are discussed. Using ciprofloxacin with its long lasting and extremely bitter taste as an example, the pharmaceutical development of an oral liquid formulation and the pharmacokinetic investigations in healthy volunteers are described.

Administration, Oral↗
PubMed1988

[Evaluation of retard drug forms with special reference to their therapeutic aspects].

The useful development and application of controlled-release dosage forms is an important possibility to improve the pharmacotherapy of many diseases. However, according to the present social conditions of reproduction the introduction of a new drug has to be directed not only to a high therapeutic benefit but also to an increased social efficiency i.e., to an improvement of cost-benefit-relation. In the present study, therefore, the effect of using controlled-release dosage forms on the development of social efficiency is discussed. Basing on a comprehensive estimation of the therapeutic efficiency (therapeutic advantages and disadvantages) of controlled-release dosage forms the criteria of cost and benefit being of importance for a complex evaluation of efficiency are described.

Delayed-Action Preparations↗
PubMed2005

Role of water in the physical stability of solid dosage formulations.

The interaction of moisture with pharmaceutical solids is highly crucial to an understanding of water-based processes, for example, manufacturing processes or prediction of solid dosage form stability and shelf life. Both the active pharmaceutical ingredient (API) and excipients in the formulation have different moisture sorption properties that can result in unexpected processing-induced phase transitions and they can affect solid-state phase transitions in the final dosage forms. The character of excipient effects on the stability of formulation. Phase transformations in formulations can lead to instability in physicochemical, biopharmaceutical, and processing properties of products. The aim of the present study was to investigate the water sorption properties of different excipients, model the sorption isotherms, examine the phase transitions, and identify differences of excipients in solid dosage form stability using dynamic vapor sorption analysis, near-infrared spectroscopy, and X-ray diffraction methods. The thermal processing was carried out with a variable temperature X-ray powder diffractometer to compare the dehydration behavior of wet excipients and evaluate solid-state properties during heating. These results showed that despite some limitations, moisture sorption isotherms of excipients are useful in predicting solid-state stability, interactions at early stages of formulation development, and effects of moisture on physicochemical properties of the final dosage forms.

Cellulose↗
PubMed2001

The role of particle size distribution on bioavailability of cyclosporine: novel drug delivery system.

During the long period of cyclosporine-containing dosage forms development a lot of significant findings have been done especially in the field of drug delivery systems. Currently available drugs are based, from technological point of view, on self-dispersible drug delivery systems, which contain cyclosporine solved in pharmaceutically acceptable vehicle. One can find difference among particular systems a) at particle size distribution after dispergation, b) at composition and c) at bioavailability of cyclosporine. As far as improvement of bioavailability between original brand leader formulation Sandimmune and recent brand leader formulation Neoral was followed by significant improvement in particle size distribution it was generally assumed that the reason for this improvement have been found. Several other formulations e.g. Consupren or SangCyA--self-dispersible systems, more or less correspond with above mentioned theory that smaller is better and by this principle bridged liquid based dosage forms with solid dosage forms. Bioavailability of novel drug delivery system which gives coarse dispersion with average particle size between 1-150 microns when dispersed have been tested on healthy volunteers. No difference among pharmacokinetic parameters of novel drug delivery system and microemulsion system have been observed in spite of fact that average particle size of novel system is almost 1000x bigger.

Adult↗
PubMed1996

IPDAS: a novel technology brings new benefits when applied to naproxen sodium.

The Intestinal Protective Drug Absorption System (IPDAS) is a new oral drug delivery approach that is applicable to gastrointestinal (GI) irritant drugs, including the nonsteroidal anti-inflammatory drug (NSAID) class. Although naproxen, as the free acid or the sodium salt, has pharmacokinetic characteristics that are consistent with once-daily dosing, the GI irritant and ulcerogenic potential associated with a large bolus dose of naproxen precludes safe use of an immediate-release form. In addition, the desired pharmacodynamic activity of a once-daily dosage form of naproxen requires rapidly available naproxen for a prompt onset of analgesic activity, as well as a prolonged phase of absorption to provide 24-hour analgesic/anti-inflammatory activity. Naprelan (naproxen sodium; Wyeth-Ayerst Laboratories, Philadelphia, Pennsylvania) controlled-release tablets are a unique dosage form designed to achieve the desired features of such a once-daily presentation. Through a series of in vivo studies, the pharmaceutical design features of the product have been confirmed in humans using a combination of imaging and pharmacokinetic characterization. In addition, the potential for limiting any undesirable GI adverse events has been supported by evaluation of the GI toxicity of Naprelan in specialized animal toxicity studies. Naprelan exhibited in vivo performance characteristics that support the hypothesis that, as a once-daily dosage form, it may demonstrate safety and efficacy advantages in clinical evaluation.

Adolescent↗