ABSTRACT
A viscous solution of low molecular weight chitosan (CH) at 5% w/v (10.2 kDa, 75 % deacetylated, 1451 cP at 25 °C) was associated with a microemulsion (ME) that undergoes a phase transition after water absorption in situ (≈28 % w/w), forming a more viscous liquid crystal, which was potentially evaluated as a topical vehicle. The ME was selected from a phase diagram, selecting a composition based on Tween® 80 (52 %), myristate isopropyl (28 %), and the aqueous phase (water and polyethylene glycol 400, 60:40 w/w) (20 %), which was after replaced by CH and herbal medicines (HM). HM are alternatives to treat candidiasis, and Stryphnodendron adstringens shell extract, characterized by molecular networking, and Melaleuca alternifolia Chell essential oil (46 % of terpinen-4-ol), showed in vitro activity against Candida albicans. Associating CH in ME improved the mechanical properties of the topical formulation, as adhesiveness, which is an advantageous feature for the topical treatment of vulvovaginal candidiasis.
Subject(s)
Candida albicans/drug effects , Chitosan/chemistry , Fabaceae/chemistry , Melaleuca/chemistry , Tea Tree Oil/chemistry , Candida albicans/growth & development , Catechin/chemistry , Catechin/isolation & purification , Catechin/pharmacology , Emulsions , Flavonoids/chemistry , Flavonoids/isolation & purification , Flavonoids/pharmacology , Liquid Crystals/chemistry , Microbial Sensitivity Tests , Molecular Weight , Myristates/chemistry , Plant Extracts/chemistry , Polyethylene Glycols/chemistry , Polysorbates/chemistry , Proanthocyanidins/chemistry , Proanthocyanidins/isolation & purification , Proanthocyanidins/pharmacology , Rheology , Tea Tree Oil/pharmacology , Water/chemistryABSTRACT
Chlorthalidone (CTD) is an antihypertensive drug and exhibits four crystalline forms: I, II, III and IV. In this paper, the incidence of CTD polymorphs in raw materials and in tablets as well as the solubility and dissolution properties of forms I and II have been studied. Raw materials were named as A, B, C, D, and E and tablets as Reference, G1, G2 and S. Using powder X-ray diffraction and infrared spectroscopy analyses we found that A, B, E, Reference and G1 contain CTD form I; C, D and S contain predominantly form II; and G2 contain a mixture of both forms. Solubility experiments showed that form II is up to 49% more soluble than form I and dissolution studies showed a significantly effect of the polymorphism on the dissolution of CTD from tablets. Based on these results, it was concluded that only the CTD form I is acceptable for preparation of tablet form. Moreover, we proposed the polymorphic quality control of CTD raw materials and tablets.
Subject(s)
Antihypertensive Agents/chemistry , Chlorthalidone/chemistry , Drug Compounding , Antihypertensive Agents/analysis , Chemistry, Pharmaceutical , Chlorthalidone/analysis , Chromatography, High Pressure Liquid , Powders , Quality Control , Reference Standards , Solubility , Solvents , Spectrophotometry, Infrared , Tablets , X-Ray DiffractionABSTRACT
A liberaçäo transdérmica de muitos fármacos é dificultada pelas características de barreira do estrato córneo. Promotores químicos de absorçäo cutânea säo capazes de interagir com os constituintes do estrato córneo, induzindo aumento temporário e reversível na permeabilidade da pele. O objetivo deste trabalho foi avaliar a influência de sistemas monoleína (monoleato de glicerol)/solventes na absorçäo percutânea de um fármaco lipofílico (a progesterona), através do estrato córneo de camundongos sem pelo, bem como o efeito da monoleína nas características estruturais do estrato córneo, por meio de microscopia eletrônica de varredura...