Cetirizine Hydrochloride

Cetirizine and meclizine are over-the-counter H1 antihistamines available in many countries. Meclizine can have a considerable sedative effect and can therefore be used in drug-facilitated crimes to incapacitate victims. Cetirizine does not usually produce a sedative effect but is often detected in drug-facilitated crimes. Quantification possibilities, reference concentrations, and temporal patterns of these antihistamines in hair, however, remain unknown. A single-dose study was conducted to investigate whether a single dose of cetirizine and meclizine could be quantified in head hair up to one year after intake. Twelve adult volunteers ingested a single dose of cetirizine (8.4 mg) and meclizine (23 mg). Hair samples were collected one, three, five, and twelve months after intake and analyzed using LC-MS/MS, with a lower limit of quantification of 1 pg/mg. Cetirizine was quantifiable in 100%, 100%, and 92% of the hair samples collected one, three, and five months post-intake, respectively. Meclizine was quantifiable in 100%, 92%, and 67% of the corresponding samples. In contrast, at one year post-intake, cetirizine and meclizine were quantifiable in only 40% and 10% of hair samples, respectively. Concentrations determined in 1-cm-long hair segments within one year after intake ranged from 0 to 14 pg/mg for cetirizine and from 0 to 19 pg/mg for meclizine. The findings demonstrate that a single dose of cetirizine or meclizine may be detectable and quantifiable in hair for several months. Moreover, temporal patterns following a single dose may resemble those observed after repeated intake, highlighting the need for drug-specific single-dose studies.

Abstract: Background: Chemotherapy-induced alopecia negatively impacts the mental health of cancer patients. Topical minoxidil, a widely recommended drug for hair regrowth, causes scalp irritation and contact dermatitis. Oral minoxidil causes multiple cardiovascular and neurological side effects. Cetirizine hydrochloride, an antihistamine with a better safety profile than minoxidil, may stimulate hair follicle activity by modulating prostaglandin levels. Objectives: The present study aimed to develop a cetirizine hydrochloride-loaded emulgel and evaluate its potential, in combination with microneedling, for the treatment of chemotherapy-induced alopecia. Methods: Different emulgel formulations comprising cetirizine HCl, liquid paraffin, carbopol 940, propylene glycol, oleic acid, Tween 20, Span 20 and propylparaben were optimized using central composite design and response surface methodology. Physicochemical evaluation of the prepared emulgel included physical examination, determination of pH, viscosity, spreadability, drug content and stability. Interactions and compatibility among formulation constituents were assessed using In-silico analysis and Fourier transform infrared spectroscopy. In-vitro drug release, ex-vivo permeation and in-vivo hair growth studies were carried out to evaluate the performance efficiency of emulgel. Results: The prepared emulgels exhibited acceptable physicochemical properties and remained stable for 3 months. Constituents were found to be compatible with each other. The optimized formulation F4 released >95% drug at pH 5.5 within 360 minutes. During an ex-vivo study, ~94% of the drug permeated across rat skin within 6 hours following application of emulgel on the microneedle-pretreated skin. In cyclophosphamide-induced alopecia in rats, application of emulgel to microneedle-pierced skin for 15 days promoted hair growth. Conclusion: The prepared cetirizine HCl-loaded emulgel and microneedle combination may be a promising approach to treating chemotherapy-induced alopecia.