A model to evaluate the pharmacokinetic and pharmacodynamic variables of extended-release products using in vivo tissue microdialysis in humans: bupivacaine-loaded microcapsules.

Evaluation of the Pharmacokinetic Profile of Ultra Rapid Lispro Administered Subcutaneously at Different Injection Sites

Changes in blood flow close to subcutaneous insulin injection sites in stable and brittle diabetics.

Morphine absorption from subcutaneous and intramuscular injection sites is dependent on local skin and muscle blood flow. Normally, drug absorption from intramuscular and subcutaneous injections at the same anatomical site is comparable, but spinal anesthesia alters muscle and skin blood flow in the blocked area. This study measured morphine absorption from pairs of intramuscular and subcutaneous injection sites at vastus lateralis and deltoid following a single dose of morphine sulfate in the presence of spinal anesthesia. Differences between the maximum concentration achieved after injection (Cmax) and the time at which this occurred (Tmax) were not significant when absorption for each "same-site" pair of injections was compared, but Tmax after intramuscular injection at vastus lateralis was significantly longer than that observed following either intramuscular or subcutaneous injection at the deltoid (P < 0.05 for both comparisons). Cmax/Tmax ratios and the area under concentration time curve (AUC) also were analyzed, but there were no statistically significant differences among any of the four groups.

In vitro model for predicting bioavailability of subcutaneously injected monoclonal antibodies

Pharmacokinetics (PK) and Pharmacodynamics (PD) of Subcutaneous Versus Intravenous Administration of Bortezomib in Patients with Relapsed Multiple Myeloma: Effects of Subcutaneous Injection Site and Concentration, and Patient Characteristics

To use noninvasive fluorescence imaging to investigate the influence of molecular weight (MW) of proteins on the rate of loss from a subcutaneous (SC) injection site and subsequent uptake by the draining lymph nodes in mice. Bevacizumab (149kDa), bovine serum albumin (BSA, 66kDa), ovalbumin (44.3kDa) or VEGF-C156S (23kDa), labeled with the near infrared dye IRDye 680, were injected SC into the front footpad of SKH-1 mice. Whole body non-invasive fluorescence imaging was performed to quantitate the fluorescence signal at the injection site and in axillary lymph nodes. The half-life values, describing the times for 50% loss of proteins from the injection site, were 6.81h for bevacizumab, 2.85h for BSA, 1.57h for ovalbumin and 0.31h for VEGF-C156S. The corresponding axillary lymph node exposure, represented as the area of the % dose versus time curve, was 6.27, 5.13, 4.06 and 1.54% dose ∙ h, respectively. Our results indicate that the rate of loss of proteins from a SC injection site is inversely related to MW of proteins, while lymph node exposure is proportionally related to the MW of proteins in a mouse model.

Methotrexate injection site reactions: Case report and literature review

Subcutaneous administration of low-molecular-weight heparin (LMWH) may cause complications such as haematoma, bruising and pain at different injection sites. Several studies have been carried out to investigate whether bruising and pain depend on injection sites; however, the results have been conflicting, and a clear consistent conclusion has not been reached. The purpose of this systematic review and meta-analysis was to assess the incidence and severity of bruising and pain after subcutaneous injection of LMWH in different sites. Two reviewers independently searched the Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure (CNKI) databases for randomized controlled and self-controlled trials reporting side-effects from LMWH with different subcutaneous injection sites. Cochrane bias risk assessment tools and the Newcastle-Ottawa Scale (NOS) were used to evaluate the quality of the randomized controlled and self-controlled trials, respectively. Rev Man 5.3 software was used to analyse the data that were extracted after quality assessment to determine the incidence and severity of side-effects at different subcutaneous injection sites. A total of eleven studies were included in this analysis. The meta-analysis provided evidence that subcutaneous injection in the abdominal area had a lower incidence of bruising than that in the arm area (risk ratios: 0.76; 95% confidence interval: 0.64-0.90; I2 =52%, p<.05), but the difference in the bruising size between the two injection sites was marginally significant (standardized mean difference: 0.08; 95% confidence interval: -0.45 to 0.62; I2 =85%, p>.05). There was also no significant difference in the bruising size between subcutaneous injection in the abdominal area and subcutaneous injection in the thigh area (standardized mean difference: -0.16; 95% confidence interval: -0.34 to 0.22; I2 =32%, p>.05). Subcutaneous injections in the abdominal area had a lower severity of pain than injections in the arm area (risk ratios: 0.57; 95% confidence interval: 0.48-0.67; I2 =81%; p<.05), but no statistically significant difference was shown between the pain intensity in the abdominal and arm area (mean difference: -1.64; 95% confidence interval: -4.36 to 1.08; I2 =99%; p>.05). Subcutaneous injection of LMWH in the abdominal area could reduce the incidence of side-effects at the injection site and reduce patient discomfort. The abdomen is proposed as the first choice of injection site for LMWH. The findings provide useful information to nurses in clinical practice when choosing the subcutaneous injection site for LMWH.

Background Widespread use of subcutaneous injection for parenteral medications is likely to be related to high medication bioavailability and rapid onset of action. Correct subcutaneous injection technique and site selection are essential for nursing care quality and patient safety. Aim The study aimed to determine nurses’ knowledge and practice preferences regarding subcutaneous injection technique and administration site selection. Design This cross-sectional study took place between March and June 2021. Methods This study included 289 nurses, willing to participate who worked in units performing subcutaneous injections in a university hospital in Turkey. Results Most nurses reported their preferred administration site for subcutaneous injections was the lateral aspects of the upper arm. More than half of the nurses did not use a rotation chart, they swabbed the skin before a subcutaneous injection, and they always pinched the skin at the injection site; 50% of nurses reported always administering subcutaneous injections at an angle of either 90 or 45 degrees. Most nurses performed an injection in less than 30 s and waited for 10 s before withdrawing the needle. They did not apply massage onto the site following the injection. Nurses’ knowledge of subcutaneous injection was at a moderate level. Conclusions Nurse knowledge of best practice subcutaneous injection administration and site selection could be improved in line with current evidence to improve personcentred and quality and safe care delivery. Future research should involve developing and evaluating educational strategies and practice standards to enhance nurse understanding of best practice evidence to meet patient safety goals.

Patients diagnosed with an advanced-stage cancer present a dismal prognosis due to the presence of metastases. From the primary tumor, the cancer cells are disseminated via lymphatic circulation; metastases develop initially in lymph nodes. Therefore, the targeting of lymph nodes needs to be improved in the design of future chemotherapy, and one way to ensure this targeting is by using the subcutaneous (SC) route. Using lipid nanocapsules (LNCs) (40 nm and fluorescently-labeled with DiD) as nanocarriers, a correlation between the SC injection site (behind the neck, the right and left flanks, and above the tail) for LNC administration and specific lymph node accumulation (left and right cervical, axillary and inguinal lymph nodes) was achieved for Sprague-Dawley rats. The pharmacokinetic and biodistribution profiles confirmed the absence of LNCs in systemic circulation after SC administration due to the optimal size of the LNCs. With appropriate SC administration, LNCs can accumulate in specific lymph nodes, whereas IV administration led to a weak accumulation of LNCs in all lymph nodes. Specific accumulation followed the lymph flow: bottom-up from the lower to upper limbs and top down from the head, with two lymph circulation partitions: right upper limb and the rest. Administration above the tail presented high inguinal and axillary lymph node accumulation whereas weak accumulation was observed after administration behind the neck. LNCs administered in the left flank only accumulated in the left inguinal and axillary lymph nodes, whereas left and right inguinal and axillary lymph nodes presented accumulation after administration in the right flank. Cervical lymph nodes, in the opposite direction of lymph flow, were never targeted after SC administration, whatever the injection site.

Comparative canine Pharmacokinetics–Pharmacodynamics of Fospropofol Disodium Injection, Propofol Eemulsion, and Cyclodextrin-Enabled Propofol Solution Following Bolus Parenteral Administration

Intra-articular injection of biologic anti-rheumatic drugs enhances local exposure to the joint-draining lymphatics

CHRONOBIOLOGY investigates biologic rhythms that are involved in the organization of living organisms. Biologic rhythms consist of variations of biologic phenomena that are periodic and foreseeable in time. They are genetically determined as indicated by their persistence during constant conditions such as continuous light or darkness. Temporal variations in cycles of light– dark, rest–activity, fasting–eating, and other environmental conditions, defined as synchronizers, give the organism temporal markers and thus impose their period on these biologic rhythms. These rhythms can therefore be characterized by different periods, leading to the division of circadian (a period of approximately 24 h), ultradian (a cycle that is shorter than 1 day), and infradian (a cycle that may last weeks, months, or seasons). These clocks influence how our bodies change throughout the day, affecting blood pressure, activity of the immune system, blood coagulation, and gastric and renal functions. Almost all hormones are regulated by circadian rhythms. For example, cortisol naturally decreases to its lowest concentrations at bedtime and reaches its highest concentrations during the early waking hours. This variation may be fit to a sinusoidal function by the cosinor method, a linear method of least squares (fig. 1). This function is characterized by parameters such as the midline-estimating statistic of rhythm (MESOR), i.e., the mean level that is equal to the 24-h average), amplitude (half of the peak-to-trough difference of the fitted cosinus function), and acrophase (the crest time of rhythm given in degrees, where 360° corresponds to a 24-h cycle, or in hours and minutes). Other methods, such as Fourier transformation, may be used to detect the periodicity of the rhythm. Biologic rhythms are influenced by socioecologic factors, such as jet lag and shiftwork, as well as by illness and drugs. Available clinical data have shown that signs and symptoms are not constant over time and often have cyclic patterns. More strokes and heart attacks occur in the morning compared with any other time of day, and people with osteoarthritis tend to feel less pain in the morning than at night. Studies also suggest that chemotherapy and treatments for asthma and arthritis may be more effective and less toxic if drugs are administered at carefully selected times. Taking into account the circadian rhythms for medical treatment by choosing the time of day for drug administration is called chronotherapy. Drug effects can be optimized and side effects can be reduced by basing drug administration on the circadian patterns of a disease. Chronopharmacology is the study of the influence of the moment of administration of a drug (hour, month, and year) on its response according to the temporal structure of the organism receiving it. Chronopharmacology also studies the drug-induced alterations of biologic rhythms. Two aspects of chronopharmacology must be distinguished: the time of administration of a drug may determine a different response from a qualitative or a quantitative point of view (chronopharmacodynamics) and/or a different effective drug concentration (chronopharmacokinetics). Pharmacokinetic parameters are influenced by different physiologic functions displaying circadian rhythm. Temporal changes of drug kinetics have been reported in animals and humans for more than a hundred drugs, including anesthetics. It has been shown, for example, that despite a constant infusion rate of heparin, the risk of bleeding and the activated partial thromboplastin are higher at night. Chronopharmacokinetic data may partly explain chronopharmacodynamic phenomena. Knowledge of the influence of the time of administration on the drug kinetics could therefore have implications for its prescription by modulating the distribution of the total daily dose over a 24-h period. The aim of this review is to provide an update on the chronobiologic and chronopharmacologic findings that could have an impact on the daily practice of anesthesiology and/or research in this area.

Utility of injection site tumorigenicity in assessing the carcinogenic risk of chemicals to man

Monoclonal antibodies (mAbs) are commonly administered by subcutaneous (SC) route. However, bioavailability is often reduced after SC administration. In addition, the sequential transfer of mAbs through the SC tissue and lymphatic system is not completely understood. Therefore, major objectives of this study were a) To understand absorption of mAbs via the lymphatic system after SC administration using physiologically based pharmacokinetic (PBPK) modeling, and b) to demonstrate application of the model for prediction of SC pharmacokinetics (PK) of mAbs. A minimal PBPK model was constructed using various physiological parameters related to the SC injection site and lymphatic system. The remainder of the body organs were represented using a 2-compartment model (central and peripheral compartments), with parameters derived from available intravenous (IV) PK data. The IV and SC clinical PK data of a total of 10 mAbs were obtained from literature. The SC PK data were used to estimate the lymphatic trunk-lymph node (LN) clearance. The mean estimated lymphatic trunk-LN clearance obtained from 37 SC PK profiles of mAbs was 0.00213 L/h (0.001332 to 0.002928, 95% confidence intervals). The estimated lymphatic trunk-LN clearance was greater for the mAbs with higher isoelectric point (pI). In addition, the estimated clearance increased with decrease in the bioavailability. The minimal PBPK model identified SC injection site lymph flow, afferent and efferent lymph flows, and volumes associated with the SC injection site, lymphatic capillaries and lymphatic trunk-LN as important physiological parameters governing the absorption of mAbs after SC administration. The model may be used to predict PK of mAbs using the relationship of lymphatic trunk-LN clearance and the pI. In addition, the model can be used as a bottom platform to incorporate SC and lymphatic in vitro clearance data for mAb PK prediction in the future.