The Merck Index of Chemicals and Drugs An Encyclopedia for the Chemist, Pharmacist, Physician and Allied Professions Sixth edition Pp xiv + 1167 (Rahway, NJ: Merck and Company, Inc, 1952) 750 dollars; thumb-indexed, 8 dollars

The Merck Index

Critical factors in the release of drugs from sustained release hydrophilic matrices

Venous thromboembolism

Carrageenan and its applications in drug delivery.

Drug dosage forms contain many components in addition to the active pharmaceutical ingredient(s) to assist in the manufacturing process as well as to optimise drug delivery. Due to advances in drug delivery technology, excipients are currently included in novel dosage forms to fulfil specific functions and in some cases they directly or indirectly influence the extent and/or rate of drug release and absorption. Since plant polysaccharides comply with many requirements expected of pharmaceutical excipients such as non-toxicity, stability, availability and renewability they are extensively investigated for use in the development of solid oral dosage forms. Furthermore, polysaccharides with varying physicochemical properties can be extracted from plants at relatively low cost and can be chemically modified to suit specific needs. As an example, many polysaccharide-rich plant materials are successfully used as matrix formers in modified release dosage forms. Some natural polysaccharides have even shown environmental-responsive gelation characteristics with the potential to control drug release according to specific therapeutic needs. This review discusses some of the most important plant-derived polymeric compounds that are used or investigated as excipients in drug delivery systems.

https://www.mdpi.com/1420-3049/14/7/2602/pdf

Polymeric Plant-derived Excipients in Drug Delivery

Controlled-release matrix tablets of ibuprofen using cellulose ethers and carrageenans: effect of formulation factors on dissolution rates.

Aqueous solubility is an important parameter for the development of liquid formulations and in the determination of bioavailability of oral dosage forms. Ibuprofen (IB), a nonsteroidal anti-inflammatory drug, is a chiral molecule and is currently used clinically as a racemate (racIB). However, the S form of ibuprofen or S(+)-ibuprofen (SIB) is the biologically active isomer and is primarily responsible for the antiinflammatory activity. Phase solubility studies were carried out to compare the saturation solubilities of racIB and SIB in the presence of common pharmaceutical solvents such as glycerol, sorbitol solution, propylene glycol (PG), and polyethylene glycol (PEG 300) over the range of 20% to 80% v/v in aqueous based systems. The solubilities of the two compounds were also compared in the presence of cyclodextrins such as beta cyclodextrin (CD), hydroxypropyl beta cyclodextrin (HPCD), and beta cyclodextrin sulfobutyl ether sodium salt (CDSB) over the range of 5% to 25% w/v. Solubility determinations were carried at 25 degrees C and 37 degrees C. Cosolvents exponentially increased the solubility of both SIB and racIB, especially in the presence of PG and PEG 300. Glycerol was not very effective in increasing the aqueous solubilities of both compounds, whereas sorbitol solution had a minimal effect on their solubility. PG and PEG 300 increased the solubility of SIB by 400-fold and 1500-fold, respectively, whereas the rise in solubility for racIB was 193-fold and 700-fold, respectively, at 25 degrees C for the highest concentration of the cosolvents used (80% v/v). Of the two compounds studied, higher equilibrium solubilities were observed for SIB as compared with racIB. The derivatized cyclodextrins increased the aqueous solubility of racIB and SIB in a concentration-dependent manner giving AL type of phase diagrams. The phase solubility diagrams indicated the formation of soluble inclusion complexes between the drugs and HPCD and CDSB, which was of 1:1 stoichiometry. The addition of underivatized CD reduced the solubility of racIB and SIB via the formation of an insoluble complex. The S form formed more stable complexes with HPCD and CDSB as compared with raclB. The solubilization process is discussed in terms of solvent polarity and differential solid-state structure of raclB and SIB. The thermodynamic parameters for the solubilization process are presented.

Solubility of ( ± )-Ibuprofen and S ( + )-Ibuprofen in the Presence of Cosolvents and Cyclodextrins

Study Objective. To compare the cost-effectiveness of warfarin or enoxaparin with no prophylaxis for prevention of venous thromboembolism in patients undergoing total knee replacement (TKR) or knee arthroplasty.



Design. Literature search and retrospective database analysis.



Patients. Cohort of 42,692 patients over 40 years old who underwent TKR or knee arthroplasty, with a subsequent length of stay of at least 1 day, and who did not die postoperatively.



Measurements and Main Results. Both warfarin and enoxaparin were superior to no prophylaxis with regard to costs and clinical outcomes. Enoxaparin was associated with medical charges of $26,455/patient and prevented 194 deaths/10,000 patients. Warfarin was associated with medical charges of $27,360/patient and prevented 124 deaths/10,000 patients.



Conclusions. A wide range of model estimates and assumptions identify enoxaparin as the prophylaxis modality of choice for preventing venous thromboembolism and subsequent clinical complications following total knee replacement surgery.

Cost/death averted with venous thromboembolism prophylaxis in patients undergoing total knee replacement or knee arthroplasty.

The aqueous solubility of guaifenesin, a highly water‐soluble drug, in the presence of salts, sugars, and cosolvents was determined at 25°C and 40°C. The solubility of drug at both temperatures was...

Jayanti Nerurkar

Papers

Controlled-release matrix tablets of ibuprofen using cellulose ethers and carrageenans: effect of formulation factors on dissolution rates.

Solubility of ( ± )-Ibuprofen and S ( + )-Ibuprofen in the Presence of Cosolvents and Cyclodextrins

Cost/death averted with venous thromboembolism prophylaxis in patients undergoing total knee replacement or knee arthroplasty.

Solubility of Guaifenesin in the Presence of Common Pharmaceutical Additives