Search results for "Absorption"
showing 10 items of 2701 documents
Biowaiver Monographs for Immediate-Release Solid Oral Dosage Forms: Nifedipine
2015
Literature data relevant to the biopharmaceutical properties of the active pharmaceutical ingredient (API) nifedipine are reviewed to evaluate whether a waiver of in vivo bioequivalence (BE) testing of immediate-release (IR) dosage forms formulated as tablets and soft gelatin capsules is warranted. Nifedipine's solubility and permeability, its therapeutic use and index, pharmacokinetics, food drug interactions, and any reported BE/bioavailability problems were all taken into consideration. Solubility and BA data indicate conclusively that nifedipine is a class II substance of biopharmaceutics classification system (BCS) and that the formulation of drug product plays a key role on the dissol…
Drugs and the Colon
1983
It is not our intention to review drug effects in the colon, which was done extensively and profoundly by Forth and Rummel1 and Powell.2 Our contribution will present studies of drug effects on physiological absorption and secretion processes obtained in the intact human colon and based on results of intestinal perfusion studies of the whole colon and measurements of transepithelial electrical potential difference (PD) in the rectosigmoid colon. These are at present the practiced and—regarding perfusion studies—most accurate techniques in the hands of clinicians to directly study drug effects on a local dose-response scale in the intact human colon. Since these methods are relatively new an…
Carbamazepine transbuccal delivery: the histo-morphological features of reconstituted human oral epithelium and buccal porcine mucosae in the transmu…
2009
Transbuccal drug delivery is an attractive way of administration since several well-known advantages are provided, especially with respect to peroral management. Carbamazepine (CBZ) is an anticonvulsant which is useful in controlling neuropathic pain, and it is currently administered by peroral route, although its absorption and bioavailability is limited due to various factors. The oral cavity could be an interesting site for transbuccal CBZ delivery due to two properties: slow administration of constant low drug doses and less dose-related side effects. However, in transbuccal absorption a major limitation could be the low permeability of the mucosa which results in low drug bioavailabil…
Pharmacology of Acamprosate: An Overview
2003
In the last years important advances have been made in the development of drugs for the treatment of alcohol addiction. Acamprosate (calcium bis‐acetylhomotaurine) is one of the better established drugs in this field on the European market. This review focuses first on the pharmacokinetics of acamprosate. The published data and the recent advances in our knowledge on the mechanisms involved in the intestinal absorption and elimination of this drug are summarized. The importance of pharmacokinetics for the proper clinical use of acamprosate is highlighted. The anti‐relapse as well as the well‐known effects of acamprosate on ethanol intake are discussed. The recent experiments in animal model…
Microfibrillar polymeric ocular inserts for triamcinolone acetonide delivery.
2019
Abstract Despite eye drops generally represent the most convenient, simple and patient-friendly formulations to treat ocular diseases, they suffer from poor retention on the ocular surface and low drug bioavailability leading to the necessity of prolonged and continuous treatment over time. Therefore, ocular insert could represent an innovative way to benefit from ocular topical administration while minimizing all the relevant limitation related to this route of administration. Polymeric non-erodible mucoadhesive ocular inserts should be comfortable and should rapidly adhere on the ocular surface, remain in situ for prolonged period, assure a reproducible and controlled drug release as well…
Influence of Chemical Enhancers and Iontophoresis on the In Vitro Transdermal Permeation of Propranolol: Evaluation by Dermatopharmacokinetics
2018
[EN] The aims of this study were to assess, in vitro, the possibility of administering propranolol transdermally and to evaluate the usefulness of the dermatopharmacokinetic (DPK) method in assessing the transport of drugs through stratum corneum, using propranolol as a model compound. Four chemical enhancers (decenoic and oleic acid, laurocapram, and R-(+)-limonene) and iontophoresis at two current densities, 0.25 and 0.5 mA/cm(2) were tested. R-(+)-limonene, and iontophoresis at 0.5 mA/cm(2) were proven to be the most efficient in increasing propranolol transdermal flux, both doubled the original propranolol transdermal flux. Iontophoresis was demonstrated to be superior than the chemical…
The Biopharmaceutics Classification System: Subclasses for in vivo predictive dissolution (IPD) methodology and IVIVC
2013
The Biopharmaceutics Classification System (BCS) has found widespread utility in drug discovery, product development and drug product regulatory sciences. The classification scheme captures the two most significant factors influencing oral drug absorption; solubility and intestinal permeability and it has proven to be a very useful and a widely accepted starting point for drug product development and drug product regulation. The mechanistic base of the BCS approach has, no doubt, contributed to its wide spread acceptance and utility. Nevertheless, underneath the simplicity of BCS are many detailed complexities, both in vitro and in vivo which must be evaluated and investigated for any given…
Unraveling the behavior of oral drug products inside the human gastrointestinal tract using the aspiration technique: History, methodology and applic…
2020
Fluid sampling from the gastrointestinal (GI) tract has been applied as a valuable tool to gain more insight into the fluids present in the human GI tract and to explore the dynamic interplay of drug release, dissolution, precipitation and absorption after drug product administration to healthy subjects. In the last twenty years, collaborative initiatives have led to a plethora of clinical aspiration studies that aimed to unravel the luminal drug behavior of an orally administered drug product. The obtained drug concentration-time profiles from different segments in the GI tract were a valuable source of information to optimize and/or validate predictive in vitro and in silico tools, freque…
Ion-pair approach coupled with nanoparticle formation to increase bioavailability of a low permeability charged drug.
2018
Abstract Atenolol is a drug widely used for the treatment of hypertension. However, the great drawback it presents is a low bioavailability after oral administration. To obtain formulations that allow to improve the bioavailability of this drug is a challenge for the pharmaceutical technology. The objective of this work was to increase the rate and extent of intestinal absorption of atenolol as model of a low permeability drug, developing a double technology strategy. To increase atenolol permeability an ion pair with brilliant blue was designed and the sustained release achieved through encapsulation in polymeric nanoparticles (NPs). The in vitro release studies showed a pH-dependent relea…
Physical methods to promote drug delivery on mucosal tissues of the oral cavity.
2013
Introduction: The successful of drug delivery through the mucosal tissue of the oral cavity represents a current challenge as well as a great future perspective. The need for more rapid onset of action and improved absorption of medications has resulted in great development of drug delivery technologies that use physical methods to overcome the barrier properties of oral mucosae. Areas covered: This review discusses the various physical techniques which have been, and are being, explored to sustain drug delivery in the oral cavity. In particular, supersaturation, eutectic formation, iontophoresis, electroporation, sonophoresis, laser radiation, photomechanical waves, and needleless injectio…